Nucleoside-2',3'-cyclic phosphate nucleotidohydrolase. Enzymes that catalyze the hydrolysis of the 2'- or 3'- phosphate bonds of 2',3'-cyclic nucleotides. Also hydrolyzes nucleoside monophosphates. Includes EC 3.1.4.16 and EC 3.1.4.37. EC 3.1.4.-.


The cap-like structure covering the anterior portion of SPERM HEAD. Acrosome, derived from LYSOSOMES, is a membrane-bound organelle that contains the required hydrolytic and proteolytic enzymes necessary for sperm penetration of the egg in FERTILIZATION.


Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.


An early local inflammatory reaction to insult or injury that consists of fever, an increase in inflammatory humoral factors, and an increased synthesis by hepatocytes of a number of proteins or glycoproteins usually found in the plasma.


The clumping together of suspended material resulting from the action of AGGLUTININS.


Behavior which may be manifested by destructive and attacking action which is verbal or physical, by covert attitudes of hostility or by obstructionism.


The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.


The elaboration of dental enamel by ameloblasts, beginning with its participation in the formation of the dentino-enamel junction to the production of the matrix for the enamel prisms and interprismatic substance. (Jablonski, Dictionary of Dentistry, 1992).


The modification of an amino acid to an active form, for incorporation into a peptide, protein or other macromolecule. [GOC:jl]


The cell cycle phase during which chromosomes separate and migrate towards the poles of the spindle the as part of a mitotic cell cycle. [GOC:mtg_cell_cycle]


The production of ANTIBODIES by proliferating and differentiated B-LYMPHOCYTES under stimulation by ANTIGENS.


The phenomenon of antibody-mediated target cell destruction by non-sensitized effector cells. The identity of the target cell varies, but it must possess surface IMMUNOGLOBULIN G whose Fc portion is intact. The effector cell is a "killer" cell possessing Fc receptors. It may be a lymphocyte lacking conventional B- or T-cell markers, or a monocyte, macrophage, or polynuclear leukocyte, depending on the identity of the target cell. The reaction is complement-independent.


Change in the surface ANTIGEN of a microorganism. There are two different types. One is a phenomenon, especially associated with INFLUENZA VIRUSES, where they undergo spontaneous variation both as slow antigenic drift and sudden emergence of new strains (antigenic shift). The second type is when certain PARASITES, especially trypanosomes, PLASMODIUM, and BORRELIA, survive the immune response of the host by changing the surface coat (antigen switching). (From Herbert et al., The Dictionary of Immunology, 4th ed)


Physiologic mechanisms which regulate or control the appetite and food intake.


The spontaneous disintegration of tissues or cells by the action of their own autogenous enzymes.


The cellular catabolic process in which cells digest parts of their own cytoplasm; allows for both recycling of macromolecular constituents under conditions of cellular stress and remodeling the intracellular structure for cell differentiation. [GOC:autophagy, ISBN:0198547684, PMID:11099404, PMID:9412464]


Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.


The directed transport of ORGANELLES and molecules along nerve cell AXONS. Transport can be anterograde (from the cell body) or retrograde (toward the cell body). (Alberts et al., Molecular Biology of the Cell, 3d ed, pG3)


A darkly stained mat-like EXTRACELLULAR MATRIX (ECM) that separates cell layers, such as EPITHELIUM from ENDOTHELIUM or a layer of CONNECTIVE TISSUE. The ECM layer that supports an overlying EPITHELIUM or ENDOTHELIUM is called basal lamina. Basement membrane (BM) can be formed by the fusion of either two adjacent basal laminae or a basal lamina with an adjacent reticular lamina of connective tissue. BM, composed mainly of TYPE IV COLLAGEN; glycoprotein LAMININ; and PROTEOGLYCAN, provides barriers as well as channels between interacting cell layers.


behavioural response to stimulus
behavior
behavioral response to stimulus

The observable response of a man or animal to a situation.


The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.


The process of giving birth to one or more offspring.


The movement of the BLOOD as it is pumped through the CARDIOVASCULAR SYSTEM.


The process of the interaction of BLOOD COAGULATION FACTORS that results in an insoluble FIBRIN clot.


The processes of heating and cooling that an organism uses to control its temperature.


The growth and development of bones from fetus to adult. It includes two principal mechanisms of bone growth: growth in length of long bones at the epiphyseal cartilages and growth in thickness by depositing new bone (OSTEOGENESIS) with the actions of OSTEOBLASTS and OSTEOCLASTS.


Renewal or repair of lost bone tissue. It excludes BONY CALLUS formed after BONE FRACTURES but not yet replaced by hard bone.


The axon of a dorsal root ganglion cell that are responsive to pain and temperature. C-fibers are small in diameter (0.2-1.5 um) and unmyelinated. [NIF_Subcellular:nlx_subcell_20090210]


Process by which organic tissue becomes hardened by the physiologic deposit of calcium salts.


Adherence of cells to surfaces or to other cells.


The phenomenon by which dissociated cells intermixed in vitro tend to group themselves with cells of their own type.


A cell aging process stimulated in response to cellular stress, whereby normal cells lose the ability to divide through irreversible cell cycle arrest. [GOC:BHF, PMID:28682291]


Any of several ways in which living cells of an organism communicate with one another, whether by direct contact between cells or by means of chemical signals carried by neurotransmitter substances, hormones, and cyclic AMP.


The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.


The termination of the cell's ability to carry out vital functions such as metabolism, growth, reproduction, responsiveness, and adaptability.


Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.


The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.


A cell cycle phase during which nuclear division occurs, and which is comprises the phases: prophase, metaphase, anaphase and telophase. [GOC:mtg_cell_cycle]


cell growth
cellular growth
growth of cell

The process in which a cell irreversibly increases in size over time by accretion and biosynthetic production of matter similar to that already present. [GOC:ai]


cellular membrane
cytoplasmic membrane
plasma membrane lipid bilayer
plasmalemma
cell membrane

The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.


Any process involved in the controlled self-propelled movement of a cell that results in translocation of the cell from one place to another. [GOC:dgh, GOC:dph, GOC:isa_complete, GOC:mlg]


Within most types of eukaryotic CELL NUCLEUS, a distinct region, not delimited by a membrane, in which some species of rRNA (RNA, RIBOSOMAL) are synthesized and assembled into ribonucleoprotein subunits of ribosomes. In the nucleolus rRNA is transcribed from a nucleolar organizer, i.e., a group of tandemly repeated chromosomal genes which encode rRNA and which are transcribed by RNA polymerase I. (Singleton & Sainsbury, Dictionary of Microbiology & Molecular Biology, 2d ed)


Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)


The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.


A generic term for any circumscribed mass of foreign (e.g., lead or viruses) or metabolically inactive materials (e.g., ceroid or MALLORY BODIES), within the cytoplasm or nucleus of a cell. Inclusion bodies are in cells infected with certain filtrable viruses, observed especially in nerve, epithelial, or endothelial cells. (Stedman, 25th ed)


Self-replicating, short, fibrous, rod-shaped organelles. Each centriole is a short cylinder containing nine pairs of peripheral microtubules, arranged so as to form the wall of the cylinder.


The clear constricted portion of the chromosome at which the chromatids are joined and by which the chromosome is attached to the spindle during cell division.


taxis in response to chemical stimulus
chemotaxis

The movement of cells or organisms toward or away from a substance in response to its concentration gradient.


immune cell chemotaxis
leucocyte chemotaxis

The movement of leukocytes in response to a chemical concentration gradient or to products formed in an immunologic reaction.


Plant cell inclusion bodies that contain the photosynthetic pigment CHLOROPHYLL, which is associated with the membrane of THYLAKOIDS. Chloroplasts occur in cells of leaves and young stems of plants. They are also found in some forms of PHYTOPLANKTON such as HAPTOPHYTA; DINOFLAGELLATES; DIATOMS; and CRYPTOPHYTA.


The outermost extra-embryonic membrane surrounding the developing embryo. In REPTILES and BIRDS, it adheres to the shell and allows exchange of gases between the egg and its environment. In MAMMALS, the chorion evolves into the fetal contribution of the PLACENTA.


Organelles in CHROMAFFIN CELLS located in the adrenal glands and various other organs. These granules are the site of the synthesis, storage, metabolism, and secretion of EPINEPHRINE and NOREPINEPHRINE.


Either of the two longitudinally adjacent threads formed when a eukaryotic chromosome replicates prior to mitosis. The chromatids are held together at the centromere. Sister chromatids are derived from the same chromosome. (Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)


In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)


microtubule-based flagellum
eukaryotic flagellum

Populations of thin, motile processes found covering the surface of ciliates (CILIOPHORA) or the free surface of the cells making up ciliated EPITHELIUM. Each cilium arises from a basic granule in the superficial layer of CYTOPLASM. The movement of cilia propels ciliates through the liquid in which they live. The movement of cilia on a ciliated epithelium serves to propel a surface layer of mucus or fluid. (King & Stansfield, A Dictionary of Genetics, 4th ed)


The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs or environmental and physiological stimuli.


TCA cycle
Krebs cycle
tricarboxylic acid cycle

A series of oxidative reactions in the breakdown of acetyl units derived from GLUCOSE; FATTY ACIDS; or AMINO ACIDS by means of tricarboxylic acid intermediates. The end products are CARBON DIOXIDE, water, and energy in the form of phosphate bonds.


Intellectual or mental process whereby an organism obtains knowledge.


The sequential activation of serum COMPLEMENT PROTEINS to create the COMPLEMENT MEMBRANE ATTACK COMPLEX. Factors initiating complement activation include ANTIGEN-ANTIBODY COMPLEXES, microbial ANTIGENS, or cell surface POLYSACCHARIDES.


Complement activation initiated by the interaction of microbial ANTIGENS with COMPLEMENT C3B. When COMPLEMENT FACTOR B binds to the membrane-bound C3b, COMPLEMENT FACTOR D cleaves it to form alternative C3 CONVERTASE (C3BBB) which, stabilized by COMPLEMENT FACTOR P, is able to cleave multiple COMPLEMENT C3 to form alternative C5 CONVERTASE (C3BBB3B) leading to cleavage of COMPLEMENT C5 and the assembly of COMPLEMENT MEMBRANE ATTACK COMPLEX.

complement activation, alternative pathway


Pavlovian conditioning
associative learning
conditional learning
conditional response

Learning that takes place when a conditioned stimulus is paired with an unconditioned stimulus.


Learning situations in which the sequence responses of the subject are instrumental in producing reinforcement. When the correct response occurs, which involves the selection from among a repertoire of responses, the subject is immediately reinforced.


Arrest of cell locomotion or cell division when two cells come into contact.


The interaction of two or more persons or organizations directed toward a common goal which is mutually beneficial. An act or instance of working or acting together for a common purpose or benefit, i.e., joint action. (From Random House Dictionary Unabridged, 2d ed)


Sexual union of a male and a female in non-human species.


The lysis or structural demise of the corpus luteum. During normal luteolysis, two closely related events occur. First, there is loss of the capacity to synthesize and secrete progesterone (functional luteolysis) followed by loss of the cells that comprise the corpus luteum (structural luteolysis). Preventing luteolysis is crucial to maintain pregnancy. [PMID:10617764]


cytokinesis
cytokinesis involved in cell cycle

The division of the cytoplasm and the plasma membrane of a cell and its partitioning into two daughter cells. [GOC:mtg_cell_cycle]


The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)


The movement of CYTOPLASM within a CELL. It serves as an internal transport system for moving essential substances throughout the cell, and in single-celled organisms, such as the AMOEBA, it is responsible for the movement (CELL MOVEMENT) of the entire cell.


The network of filaments, tubules, and interconnecting filamentous bridges which give shape, structure, and organization to the cytoplasm.


Adjustment of the eyes under conditions of low light. The sensitivity of the eye to light is increased during dark adaptation.


The cellular and vascular changes occurring in the endometrium of the pregnant uterus just after the onset of blastocyst implantation. This process involves the proliferation and differentiation of the fibroblast-like endometrial stromal cells into large, polyploid decidual cells that eventually form the maternal component of the placenta. [ISBN:0721662544, PMID:11133685]


The normal process of elimination of fecal material from the RECTUM.


Extensions of the nerve cell body. They are short and branched and receive stimuli from other NEURONS.


The formation of dentin. Dentin first appears in the layer between the ameloblasts and odontoblasts and becomes calcified immediately. Formation progresses from the tip of the papilla over its slope to form a calcified cap becoming thicker by the apposition of new layers pulpward. A layer of uncalcified dentin intervenes between the calcified tissue and the odontoblast and its processes. (From Jablonski, Dictionary of Dentistry, 1992)


A type of junction that attaches one cell to its neighbor. One of a number of differentiated regions which occur, for example, where the cytoplasmic membranes of adjacent epithelial cells are closely apposed. It consists of a circular region of each membrane together with associated intracellular microfilaments and an intercellular material which may include, for example, mucopolysaccharides. (From Glick, Glossary of Biochemistry and Molecular Biology, 1990; Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)


A phase of the ESTROUS CYCLES that follows METESTRUS. Diestrus is a period of sexual quiescence separating phases of ESTRUS in polyestrous animals.


The process of breakdown of food for metabolism and use by the body.


An increase in the excretion of URINE. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)


The reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule which contained damaged regions. The major repair mechanisms are excision repair, in which defective regions in one strand are excised and resynthesized using the complementary base pairing information in the intact strand; photoreactivation repair, in which the lethal and mutagenic effects of ultraviolet light are eliminated; and post-replication repair, in which the primary lesions are not repaired, but the gaps in one daughter duplex are filled in by incorporation of portions of the other (undamaged) daughter duplex. Excision repair and post-replication repair are sometimes referred to as "dark repair" because they do not require light.


Compensating for the variation in the unpaired sex chromosome:autosome chromosome ratios between sexes by activation or inactivation of genes on one or both of the sex chromosomes. [GOC:ems, ISBN:0140512888, PMID:11498577]


Behaviors associated with the ingesting of water and other liquids; includes rhythmic patterns of drinking (time intervals - onset and duration), frequency and satiety.


Diminished or failed response of an organism, disease or tissue to the intended effectiveness of a chemical or drug. It should be differentiated from DRUG TOLERANCE which is the progressive diminution of the susceptibility of a human or animal to the effects of a drug, as a result of continued administration.


An auditory orientation mechanism involving the emission of high frequency sounds which are reflected back to the emitter (animal).

perception of environment using reflected sound waves


The process whose specific outcome is the progression of an embryo from its formation until the end of its embryonic life stage. The end of the embryonic stage is organism-specific. For example, for mammals, the process would begin with zygote formation and end with birth. For insects, the process would begin at zygote formation and end with larval hatching. For plant zygotic embryos, this would be from zygote formation to the end of seed dormancy. For plant vegetative embryos, this would be from the initial determination of the cell or group of cells to form an embryo until the point when the embryo becomes independent of the parent plant. [GOC:go_curators, GOC:isa_complete, GOC:mtg_sensu]


Cellular uptake of extracellular materials within membrane-limited vacuoles or microvesicles. ENDOSOMES play a central role in endocytosis.


A system of cisternae in the CYTOPLASM of many cells. In places the endoplasmic reticulum is continuous with the plasma membrane (CELL MEMBRANE) or outer membrane of the nuclear envelope. If the outer surfaces of the endoplasmic reticulum membranes are coated with ribosomes, the endoplasmic reticulum is said to be rough-surfaced (ENDOPLASMIC RETICULUM, ROUGH); otherwise it is said to be smooth-surfaced (ENDOPLASMIC RETICULUM, SMOOTH). (King & Stansfield, A Dictionary of Genetics, 4th ed)


erythrocyte differentiation
red blood cell differentiation
erythropoiesis
erythrocyte cell differentiation

The production of red blood cells (ERYTHROCYTES). In humans, erythrocytes are produced by the YOLK SAC in the first trimester; by the liver in the second trimester; by the BONE MARROW in the third trimester and after birth. In normal individuals, the erythrocyte count in the peripheral blood remains relatively constant implying a balance between the rate of erythrocyte production and rate of destruction.


In certain living species, a period of dormancy during the summer months marked by decreased metabolism.


The period in the ESTROUS CYCLE associated with maximum sexual receptivity and fertility in non-primate female mammals.


Cellular release of material within membrane-limited vesicles by fusion of the vesicles with the CELL MEMBRANE.


exploration behavior
exploration behaviour
exploratory behaviour

The tendency to explore or investigate a novel environment. It is considered a motivation not clearly distinguishable from curiosity.


A meshwork-like substance found within the extracellular space and in association with the basement membrane of the cell surface. It promotes cellular proliferation and provides a supporting structure to which cells or cell lysates in culture dishes adhere.


Interstitial space between cells, occupied by INTERSTITIAL FLUID as well as amorphous and fibrous substances. For organisms with a CELL WALL, the extracellular space includes everything outside of the CELL MEMBRANE including the PERIPLASM and the cell wall.


eating behaviour
behavioural response to food
feeding behaviour
feeding behavior
behavioral response to food

Behavioral responses or sequences associated with eating including modes of feeding, rhythmic patterns of eating, and time intervals.


Anaerobic degradation of GLUCOSE or other organic nutrients to gain energy in the form of ATP. End products vary depending on organisms, substrates, and enzymatic pathways. Common fermentation products include ETHANOL and LACTIC ACID.


The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.


An abnormal elevation of body temperature, usually as a result of a pathologic process.


The natural enzymatic dissolution of FIBRIN.


A whiplike motility appendage present on the surface cells. Prokaryote flagella are composed of a protein called FLAGELLIN. Bacteria can have a single flagellum, a tuft at one pole, or multiple flagella covering the entire surface. In eukaryotes, flagella are threadlike protoplasmic extensions used to propel flagellates and sperm. Flagella have the same basic structure as CILIA but are longer in proportion to the cell bearing them and present in much smaller numbers. (From King & Stansfield, A Dictionary of Genetics, 4th ed)


cell-cell adhesion involved in flocculation

The aggregation of suspended solids into larger clumps.


The period of the MENSTRUAL CYCLE representing follicular growth, increase in ovarian estrogen (ESTROGENS) production, and epithelial proliferation of the ENDOMETRIUM. Follicular phase begins with the onset of MENSTRUATION and ends with OVULATION.


The process of germ cell development from the primordial GERM CELLS to the mature haploid GAMETES: ova in the female (OOGENESIS) or sperm in the male (SPERMATOGENESIS).


The evacuation of food from the stomach into the duodenum.


The asymmetrical segregation of genes during replication which leads to the production of non-reciprocal recombinant strands and the apparent conversion of one allele into another. Thus, e.g., the meiotic products of an Aa individual may be AAAa or aaaA instead of AAaa, i.e., the A allele has been converted into the a allele or vice versa.


The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.


Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.


general adaptation syndrome, physiological response

physiological process during general adaptation syndrome

general adaptation syndrome, physiological process

physiological response during general adaptation syndrome

The sum of all nonspecific systemic reactions of the body to long-continued exposure to systemic stress.


The production of a dense fibrous network of neuroglia; includes astrocytosis, which is a proliferation of astrocytes in the area of a degenerative lesion.


gluconeogenesis
glucose biosynthetic process

Biosynthesis of GLUCOSE from nonhexose or non-carbohydrate precursors, such as LACTATE; PYRUVATE; ALANINE; and GLYCEROL.


A metabolic process that converts GLUCOSE into two molecules of PYRUVIC ACID through a series of enzymatic reactions. Energy generated by this process is conserved in two molecules of ATP. Glycolysis is the universal catabolic pathway for glucose, free glucose, or glucose derived from complex CARBOHYDRATES, such as GLYCOGEN and STARCH.


The synthetic chemistry reaction or enzymatic reaction of adding carbohydrate or glycosyl groups. GLYCOSYLTRANSFERASES carry out the enzymatic glycosylation reactions. The spontaneous, non-enzymatic attachment of reducing sugars to free amino groups in proteins, lipids, or nucleic acids is called GLYCATION (see MAILLARD REACTION).


Golgi apparatus
Golgi
Golgi complex location
dictyosome

A stack of flattened vesicles that functions in posttranslational processing and sorting of proteins, receiving them from the rough ENDOPLASMIC RETICULUM and directing them to secretory vesicles, LYSOSOMES, or the CELL MEMBRANE. The movement of proteins takes place by transfer vesicles that bud off from the rough endoplasmic reticulum or Golgi apparatus and fuse with the Golgi, lysosomes or cell membrane. (From Glick, Glossary of Biochemistry and Molecular Biology, 1990)


Gradual increase in the number, the size, and the complexity of cells of an individual. Growth generally results in increase in ORGAN WEIGHT; BODY WEIGHT; and BODY HEIGHT.


The ability or act of sensing and transducing ACOUSTIC STIMULATION to the CENTRAL NERVOUS SYSTEM. It is also called audition.


hematopoiesis
haemopoiesis
hemopoiesis
blood cell formation

The development and formation of various types of BLOOD CELLS. Hematopoiesis can take place in the BONE MARROW (medullary) or outside the bone marrow (HEMATOPOIESIS, EXTRAMEDULLARY).


The process which spontaneously arrests the flow of BLOOD from vessels carrying blood under pressure. It is accomplished by contraction of the vessels, adhesion and aggregation of formed blood elements (eg. ERYTHROCYTE AGGREGATION), and the process of BLOOD COAGULATION.


heterochromatin
transcriptionally silent chromatin

The portion of chromosome material that remains condensed and is transcriptionally inactive during INTERPHASE.


The dormant state in which some warm-blooded animal species pass the winter. It is characterized by narcosis and by sharp reduction in body temperature and metabolic activity and by a depression of vital signs.


The processes whereby the internal environment of an organism tends to remain balanced and stable.


Altered reactivity to an antigen, which can result in pathologic reactions upon subsequent exposure to that particular antigen.


delayed-type hypersensitivity
delayed hypersensitivity response

An increased reactivity to specific antigens mediated not by antibodies but by sensitized T CELLS.


Hypersensitivity reactions which occur within minutes of exposure to challenging antigen due to the release of histamine which follows the antigen-antibody reaction and causes smooth muscle contraction and increased vascular permeability.


Nonsusceptibility to the invasive or pathogenic effects of foreign microorganisms or to the toxic effect of antigenic substances.


Manifestations of the immune response which are mediated by antigen-sensitized T-lymphocytes via lymphokines or direct cytotoxicity. This takes place in the absence of circulating antibody or where antibody plays a subordinate role.


innate immune response
nonspecific immune response

Innate immune responses are defense responses mediated by germline encoded components that directly recognize components of potential pathogens. [GO_REF:0000022, GOC:add, GOC:ebc, GOC:mtg_sensu]


A pathological process characterized by injury or destruction of tissues caused by a variety of cytologic and chemical reactions. It is usually manifested by typical signs of pain, heat, redness, swelling, and loss of function.


The development by insects of resistance to insecticides.


The deposit of SEMEN or SPERMATOZOA into the VAGINA to facilitate FERTILIZATION.


Direct contact of a cell with a neighboring cell. Most such junctions are too small to be resolved by light microscopy, but they can be visualized by conventional or freeze-fracture electron microscopy, both of which show that the interacting CELL MEMBRANE and often the underlying CYTOPLASM and the intervening EXTRACELLULAR SPACE are highly specialized in these regions. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p792)


Cytoplasmic filaments intermediate in diameter (about 10 nanometers) between the microfilaments and the microtubules. They may be composed of any of a number of different proteins and form a ring around the cell nucleus.


The interval between two successive CELL DIVISIONS during which the CHROMOSOMES are not individually distinguishable. It is composed of the G phases (G1 PHASE; G0 PHASE; G2 PHASE) and S PHASE (when DNA replication occurs).


Structures in fishes homologous to the cortical tissue of the mammalian adrenal gland; they are in close proximity to or imbedded in the kidney.


Uptake of substances through the lining of the INTESTINES.


Contractions of the intestinal tract that include peristalsis (moving contents onward) and non-peristaltic movement (moving contents back and forth). [GOC:sl, PMID:15890336]


Thin structures that encapsulate subcellular structures or ORGANELLES in EUKARYOTIC CELLS. They include a variety of membranes associated with the CELL NUCLEUS; the MITOCHONDRIA; the GOLGI APPARATUS; the ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.


The process in which the cytoplasm of the outermost cells of the vertebrate epidermis is replaced by keratin. Keratinization occurs in the stratum corneum, feathers, hair, claws, nails, hooves, and horns. [GOC:dph, GOC:ebc, GOC:sdb_2009, GOC:tb]


Locomotor behavior not involving a steering reaction, but in which there may be a turning random in direction. It includes orthokinesis, the rate of movement and klinokinesis, the amount of turning, which are related to the intensity of stimulation.


Sense of movement of a part of the body, such as movement of fingers, elbows, knees, limbs, or weights.


The processes of milk secretion by the maternal MAMMARY GLANDS after PARTURITION. The proliferation of the mammary glandular tissue, milk synthesis, and milk expulsion or let down are regulated by the interactions of several hormones including ESTRADIOL; PROGESTERONE; PROLACTIN; and OXYTOCIN.


Relatively permanent change in behavior that is the result of past experience or practice. The concept includes the acquisition of knowledge.


lipolysis
lipid degradation
lipid catabolic process
lipid catabolism

The metabolic process of breaking down LIPIDS to release FREE FATTY ACIDS, the major oxidative fuel for the body. Lipolysis may involve dietary lipids in the DIGESTIVE TRACT, circulating lipids in the BLOOD, and stored lipids in the ADIPOSE TISSUE or the LIVER. A number of enzymes are involved in such lipid hydrolysis, such as LIPASE and LIPOPROTEIN LIPASE from various tissues.


Movement or the ability to move from one place or another. It can refer to humans, vertebrate or invertebrate animals, and microorganisms.


The period in the MENSTRUAL CYCLE that follows OVULATION, characterized by the development of CORPUS LUTEUM, increase in PROGESTERONE production by the OVARY and secretion by the glandular epithelium of the ENDOMETRIUM. The luteal phase begins with ovulation and ends with the onset of MENSTRUATION.


Morphologic alteration of small B LYMPHOCYTES or T LYMPHOCYTES in culture into large blast-like cells able to synthesize DNA and RNA and to divide mitotically. It is induced by INTERLEUKINS; MITOGENS such as PHYTOHEMAGGLUTININS, and by specific ANTIGENS. It may also occur in vivo as in GRAFT REJECTION.


A class of morphologically heterogeneous cytoplasmic particles in animal and plant tissues characterized by their content of hydrolytic enzymes and the structure-linked latency of these enzymes. The intracellular functions of lysosomes depend on their lytic potential. The single unit membrane of the lysosome acts as a barrier between the enzymes enclosed in the lysosome and the external substrate. The activity of the enzymes contained in lysosomes is limited or nil unless the vesicle in which they are enclosed is ruptured or undergoes MEMBRANE FUSION. (From Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed).


The process of altering the morphology and functional activity of macrophages so that they become avidly phagocytic. It is initiated by lymphokines, such as the macrophage activation factor (MAF) and the macrophage migration-inhibitory factor (MMIF), immune complexes, C3b, and various peptides, polysaccharides, and immunologic adjuvants.


The act and process of chewing and grinding food in the mouth.


The behavior patterns associated with or characteristic of a mother.


Melanin-containing organelles found in melanocytes and melanophores.


The adherence and merging of cell membranes, intracellular membranes, or artificial membranes to each other or to viruses, parasites, or interstitial particles through a variety of chemical and physical processes.


Complex mental function having four distinct phases: (1) memorizing or learning, (2) retention, (3) recall, and (4) recognition. Clinically, it is usually subdivided into immediate, recent, and remote memory.


Remembrance of information for a few seconds to hours.


The first MENSTRUAL CYCLE marked by the initiation of MENSTRUATION.


The last menstrual period. Permanent cessation of menses (MENSTRUATION) is usually defined after 6 to 12 months of AMENORRHEA in a woman over 45 years of age. In the United States, menopause generally occurs in women between 48 and 55 years of age.


The period from onset of one menstrual bleeding (MENSTRUATION) to the next in an ovulating woman or female primate. The menstrual cycle is regulated by endocrine interactions of the HYPOTHALAMUS; the PITUITARY GLAND; the ovaries; and the genital tract. The menstrual cycle is divided by OVULATION into two phases. Based on the endocrine status of the OVARY, there is a FOLLICULAR PHASE and a LUTEAL PHASE. Based on the response in the ENDOMETRIUM, the menstrual cycle is divided into a proliferative and a secretory phase.


The periodic shedding of the ENDOMETRIUM and associated menstrual bleeding in the MENSTRUAL CYCLE of humans and primates. Menstruation is due to the decline in circulating PROGESTERONE, and occurs at the late LUTEAL PHASE when LUTEOLYSIS of the CORPUS LUTEUM takes place.


Any process that reduces or removes the toxicity of a toxic substance. These may include transport of the toxic substance away from sensitive areas and to compartments or complexes whose purpose is sequestration of the toxic substance. [GOC:dos]


The chemical reactions in living organisms by which energy is provided for vital processes and activities and new material is assimilated.


Profound physical changes during maturation of living organisms from the immature forms to the adult forms, such as from TADPOLES to frogs; caterpillars to BUTTERFLIES.


The cell cycle phase, following prophase, during which chromosomes become aligned on the equatorial plate of the cell as part of a mitotic cell cycle. [GOC:mtg_cell_cycle]


A condition in which there is a change of one adult cell type to another similar adult cell type.


The period following ESTRUS during which the phenomena of estrus subside in those animals in which pregnancy or pseudopregnancy does not occur.


Addition of methyl groups. In histo-chemistry methylation is used to esterify carboxyl groups and remove sulfate groups by treating tissue sections with hot methanol in the presence of hydrochloric acid. (From Stedman, 25th ed)


Electron-dense cytoplasmic particles bounded by a single membrane, such as PEROXISOMES; GLYOXYSOMES; and glycosomes.


actin filament
microfilament
striated muscle filament
actin cytoskeleton

The part of the cytoskeleton (the internal framework of a cell) composed of actin and associated proteins. Includes actin cytoskeleton-associated complexes. [GOC:jl, ISBN:0395825172, ISBN:0815316194]


Slender, cylindrical filaments found in the cytoskeleton of plant and animal cells. They are composed of the protein TUBULIN and are influenced by TUBULIN MODULATORS.


Minute projections of cell membranes which greatly increase the surface area of the cell.


Expulsion of milk from the mammary alveolar lumen, which is surrounded by a layer of milk-secreting EPITHELIAL CELLS and a network of myoepithelial cells. Contraction of the myoepithelial cells is regulated by neuroendocrine signals.


Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)


A type of CELL NUCLEUS division by means of which the two daughter nuclei normally receive identical complements of the number of CHROMOSOMES of the somatic cells of the species.


A spindle that forms as part of mitosis. Mitotic and meiotic spindles contain distinctive complements of proteins associated with microtubules. [GOC:mah, GOC:vw, PMID:11408572, PMID:18367542, PMID:8027178]


anatomical structure structural organization

The development of anatomical structures to create the form of a single- or multi-cell organism. Morphogenesis provides form changes of a part, parts, or the whole organism.


The specialized postsynaptic region of a muscle cell. The motor endplate is immediately across the synaptic cleft from the presynaptic axon terminal. Among its anatomical specializations are junctional folds which harbor a high density of cholinergic receptors.


mucociliary clearance
MCC
mucociliary transport

A non-specific host defense mechanism that removes MUCUS and other material from the LUNGS by ciliary and secretory activity of the tracheobronchial submucosal glands. It is measured in vivo as mucus transfer, ciliary beat frequency, and clearance of radioactive tracers.


A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.


That phase of a muscle twitch during which a muscle returns to a resting position.


Derangement in size and number of muscle fibers occurring with aging, reduction in blood supply, or following immobilization, prolonged weightlessness, malnutrition, and particularly in denervation.


The lipid-rich sheath surrounding AXONS in both the CENTRAL NERVOUS SYSTEMS and PERIPHERAL NERVOUS SYSTEM. The myelin sheath is an electrical insulator and allows faster and more energetically efficient conduction of impulses. The sheath is formed by the cell membranes of glial cells (SCHWANN CELLS in the peripheral and OLIGODENDROGLIA in the central nervous system). Deterioration of the sheath in DEMYELINATING DISEASES is a serious clinical problem.


The long cylindrical contractile organelles of STRIATED MUSCLE cells composed of ACTIN FILAMENTS; MYOSIN filaments; and other proteins organized in arrays of repeating units called SARCOMERES .


necrosis
cellular necrosis
necrotic cell death

The death of cells in an organ or tissue due to disease, injury or failure of the blood supply.


axon terminus
axon terminal
nerve ending

Branch-like terminations of NERVE FIBERS, sensory or motor NEURONS. Endings of sensory neurons are the beginnings of afferent pathway to the CENTRAL NERVOUS SYSTEM. Endings of motor neurons are the terminals of axons at the muscle cells. Nerve endings which release neurotransmitters are called PRESYNAPTIC TERMINALS.


Slender processes of NEURONS, including the AXONS and their glial envelopes (MYELIN SHEATH). Nerve fibers conduct nerve impulses to and from the CENTRAL NERVOUS SYSTEM.


signal transmission across a synapse
neurotransmission
conduction of nerve impulse
transmission of nerve impulse
synaptic transmission

The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.


A type of intermediate filament found in the core of neuronal axons. Neurofilaments are heteropolymers composed of three type IV polypeptides: NF-L, NF-M, and NF-H (for low, middle, and high molecular weight). Neurofilaments are responsible for the radial growth of an axon and determine axonal diameter. [ISBN:0198506732, ISBN:0716731363, ISBN:0815316194]


The synapse between a neuron and a muscle.


The process in certain BACTERIA; FUNGI; and CYANOBACTERIA converting free atmospheric NITROGEN to biologically usable forms of nitrogen, such as AMMONIA; NITRATES; and amino compounds.


The residual framework structure of the CELL NUCLEUS that maintains many of the overall architectural features of the cell nucleus including the nuclear lamina with NUCLEAR PORE complex structures, residual CELL NUCLEOLI and an extensive fibrogranular structure in the nuclear interior. (Advan. Enzyme Regul. 2002; 42:39-52)


The membrane system of the CELL NUCLEUS that surrounds the nucleoplasm. It consists of two concentric membranes separated by the perinuclear space. The structures of the envelope where it opens to the cytoplasm are called the nuclear pores (NUCLEAR PORE).


nuclear pore complex location
nucleopore
nuclear pore complex
NPC
nuclear pore

An opening through the NUCLEAR ENVELOPE formed by the nuclear pore complex which transports nuclear proteins or RNA into or out of the CELL NUCLEUS and which, under some conditions, acts as an ion channel.


The chromosome region which is active in nucleolus formation and which functions in the synthesis of ribosomal RNA.


tooth development
odontogeny
odontogenesis
odontosis

The process of TOOTH formation. It is divided into several stages including: the dental lamina stage, the bud stage, the cap stage, and the bell stage. Odontogenesis includes the production of tooth enamel (AMELOGENESIS), dentin (DENTINOGENESIS), and dental cementum (CEMENTOGENESIS).


The process of germ cell development in the female from the primordial germ cells through OOGONIA to the mature haploid ova (OVUM).


Specific particles of membrane-bound organized living substances present in eukaryotic cells, such as the MITOCHONDRIA; the GOLGI APPARATUS; ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.


bone formation
bone biosynthesis
ossification

The process of bone formation. Histogenesis of bone including ossification.


The process of laying or shedding fully developed eggs (OVA) from the female body. The term is usually used for certain INSECTS or FISHES with an organ called ovipositor where eggs are stored or deposited before expulsion from the body.


The discharge of an OVUM from a rupturing follicle in the OVARY.


Attachment of the blastocyst to the uterine lining. [GOC:isa_complete, http://www.medterms.com]


Electron transfer through the cytochrome system liberating free energy which is transformed into high-energy phosphate bonds.


A unisexual reproduction without the fusion of a male and a female gamete (FERTILIZATION). In parthenogenesis, an individual is formed from an unfertilized OVUM that did not complete MEIOSIS. Parthenogenesis occurs in nature and can be artificially induced.


The behavior patterns associated with or characteristic of a father.


The state of the PENIS when the erectile tissue becomes filled or swollen (tumid) with BLOOD and causes the penis to become rigid and elevated. It is a complex process involving CENTRAL NERVOUS SYSTEM; PERIPHERAL NERVOUS SYSTEMS; HORMONES; SMOOTH MUSCLES; and vascular functions.


pentose phosphate shunt
pentose phosphate pathway
hexose monophosphate pathway
pentose-phosphate pathway

The metabolic process in which glucose-6-phosphate is oxidized to form carbon dioxide (CO2) and ribulose 5-phosphate, coupled to reduction of NADP+ to NADPH; ribulose 5-P then enters a series of reactions that can yield biosynthetic precursors (ribose-5-phosphate and erythrose-4-phosphate) and glycolytic intermediates (fructose-6-phosphate and glyceraldehyde-3-phosphate). [GOC:pde, ISBN:0198506732, MetaCyc:PENTOSE-P-PWY]


A movement, caused by sequential muscle contraction, that pushes the contents of the intestines or other tubular organs in one direction.


The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (PHAGOCYTES).


A membrane-bounded intracellular vesicle formed by maturation of an early phagosome following the ingestion of particulate material by phagocytosis; during maturation, phagosomes acquire markers of late endosomes and lysosomes. [GOC:mah, PMID:12388753, PMID:14733906]


Membrane-bound cytoplasmic vesicles formed by invagination of phagocytized material. They fuse with lysosomes to form phagolysosomes in which the hydrolytic enzymes of the lysosome digest the phagocytized material.


The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.


Chemical bond cleavage reactions resulting from absorption of radiant energy.


The use of light to convert ADP to ATP without the concomitant reduction of dioxygen to water as occurs during OXIDATIVE PHOSPHORYLATION in MITOCHONDRIA.


The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide using energy obtained from light rather than from the oxidation of chemical compounds. Photosynthesis comprises two separate processes: the light reactions and the dark reactions. In higher plants; GREEN ALGAE; and CYANOBACTERIA; NADPH and ATP formed by the light reactions drive the dark reactions which result in the fixation of carbon dioxide. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)


A biologic function, activity, or process involving either specialized organ functions, individual organs, organ systems, body parts, or whole organisms.


Coloration or discoloration of a part by a pigment.


Thin, hairlike appendages, 1 to 20 microns in length and often occurring in large numbers, present on the cells of gram-negative bacteria, particularly Enterobacteriaceae and Neisseria. Unlike flagella, they do not possess motility, but being protein (pilin) in nature, they possess antigenic and hemagglutinating properties. They are of medical importance because some fimbriae mediate the attachment of bacteria to cells via adhesins (ADHESINS, BACTERIAL). Bacterial fimbriae refer to common pili, to be distinguished from the preferred use of "pili", which is confined to sex pili (PILI, SEX).


pilomotor reflex
horripilation
goosebump reflex

Involuntary erection or bristling of hairs.


The engulfing of liquids by cells by a process of invagination and closure of the cell membrane to form fluid-filled vacuoles.


The development of the PLACENTA, a highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products between mother and FETUS. The process begins at FERTILIZATION, through the development of CYTOTROPHOBLASTS and SYNCYTIOTROPHOBLASTS, the formation of CHORIONIC VILLI, to the progressive increase in BLOOD VESSELS to support the growing fetus.


A series of progressive, overlapping events, triggered by exposure of the PLATELETS to subendothelial tissue. These events include shape change, adhesiveness, aggregation, and release reactions. When carried through to completion, these events lead to the formation of a stable hemostatic plug.


The attachment of PLATELETS to one another. This clumping together can be induced by a number of agents (e.g., THROMBIN; COLLAGEN) and is part of the mechanism leading to the formation of a THROMBUS.


Catalyze the joining of preformed ribonucleotides or deoxyribonucleotides in phosphodiester linkage during genetic processes. EC 6.5.1.


A multiribosomal structure representing a linear array of RIBOSOMES held together by messenger RNA; (RNA, MESSENGER); They represent the active complexes in cellular protein synthesis and are able to incorporate amino acids into polypeptides both in vivo and in vitro. (From Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)


The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.


A phase of the ESTROUS CYCLE that precedes ESTRUS. During proestrus, the Graafian follicles undergo maturation.


The molecular events that lead to the excision of a viral genome from the host genome. [GOC:mlg]


The first phase of cell nucleus division, in which the CHROMOSOMES become visible, the CELL NUCLEUS starts to lose its identity, the SPINDLE APPARATUS appears, and the CENTRIOLES migrate toward opposite poles.


Sensory functions that transduce stimuli received by proprioceptive receptors in joints, tendons, muscles, and the INNER EAR into neural impulses to be transmitted to the CENTRAL NERVOUS SYSTEM. Proprioception provides sense of stationary positions and movements of one's body parts, and is important in maintaining KINESTHESIA and POSTURAL BALANCE.


The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.


Disruption of the non-covalent bonds and/or disulfide bonds responsible for maintaining the three-dimensional shape and activity of the native protein.


protein maturation by peptide bond cleavage

protein maturation by peptide bond hydrolysis

Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.


The protoplasm and plasma membrane of plant, fungal, bacterial or archaeon cells without the CELL WALL.


A dynamic actin-rich extension of the surface of an animal cell used for locomotion or prehension of food.


A period in the human life in which the development of the hypothalamic-pituitary-gonadal system takes place and reaches full maturity. The onset of synchronized endocrine events in puberty lead to the capacity for reproduction (FERTILITY), development of secondary SEX CHARACTERISTICS, and other changes seen in ADOLESCENT DEVELOPMENT.


Regularly spaced gaps in the myelin sheaths of peripheral axons. Ranvier's nodes allow saltatory conduction, that is, jumping of impulses from node to node, which is faster and more energetically favorable than continuous conduction.


Cytoplasmic vesicles formed when COATED VESICLES shed their CLATHRIN coat. Endosomes internalize macromolecules bound by receptors on the cell surface.


Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.


The physiological renewal, repair, or replacement of tissue.


The total process by which organisms produce offspring. (Stedman, 25th ed)


Reproduction without fusion of two types of cells, mostly found in ALGAE; FUNGI; and PLANTS. Asexual reproduction occurs in several ways, such as budding, fission, or splitting from "parent" cells. Only few groups of ANIMALS reproduce asexually or unisexually (PARTHENOGENESIS).


reproductive behavior in a multicellular organism

The specific behavior of an organism that is associated with reproduction. [GOC:jl, GOC:pr]


The action of copying RNA into DNA by reverse transcriptase.


Multicomponent ribonucleoprotein structures found in the CYTOPLASM of all cells, and in MITOCHONDRIA, and PLASTIDS. They function in PROTEIN BIOSYNTHESIS via GENETIC TRANSLATION.


Post-transcriptional biological modification of messenger, transfer, or ribosomal RNAs or their precursors. It includes cleavage, methylation, thiolation, isopentenylation, pseudouridine formation, conformational changes, and association with ribosomal protein.


The ultimate exclusion of nonsense sequences or intervening sequences (introns) before the final RNA transcript is sent to the cytoplasm.


The discharge of saliva from the SALIVARY GLANDS that keeps the mouth tissues moist and aids in digestion.


The excitable plasma membrane of a muscle cell. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)


The repeating contractile units of the MYOFIBRIL, delimited by Z bands along its length.


A network of tubules and sacs in the cytoplasm of SKELETAL MUSCLE FIBERS that assist with muscle contraction and relaxation by releasing and storing calcium ions.


The process in which specialized SENSORY RECEPTOR CELLS transduce peripheral stimuli (physical or chemical) into NERVE IMPULSES which are then transmitted to the various sensory centers in the CENTRAL NERVOUS SYSTEM.


In the interphase nucleus, a condensed mass of chromatin representing an inactivated X chromosome. Each X CHROMOSOME, in excess of one, forms sex chromatin (Barr body) in the mammalian nucleus. (from King & Stansfield, A Dictionary of Genetics, 4th ed)


The homologous chromosomes that are dissimilar in the heterogametic sex. There are the X CHROMOSOME, the Y CHROMOSOME, and the W, Z chromosomes (in animals in which the female is the heterogametic sex (the silkworm moth Bombyx mori, for example)). In such cases the W chromosome is the female-determining and the male is ZZ. (From King & Stansfield, A Dictionary of Genetics, 4th ed)


The process in developing sex- or gender-specific tissue, organ, or function after SEX DETERMINATION PROCESSES have set the sex of the GONADS. Major areas of sex differentiation occur in the reproductive tract (GENITALIA) and the brain.


The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.


A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility.


sense of smell
olfaction
smell perception
scent perception

The ability to detect scents or odors, such as the function of OLFACTORY RECEPTOR NEURONS.


Any behavior caused by or affecting another individual or group usually of the same species.


An error-prone process for repairing damaged microbial DNA. [GOC:jl, PMID:16000023]


The structural and functional changes by which SPERMATOZOA become capable of oocyte FERTILIZATION. It normally requires exposing the sperm to the female genital tract for a period of time to bring about increased SPERM MOTILITY and the ACROSOME REACTION before fertilization in the FALLOPIAN TUBES can take place.


The anterior portion of the spermatozoon (SPERMATOZOA) that contains mainly the nucleus with highly compact CHROMATIN material.


Movement characteristics of SPERMATOZOA in a fresh specimen. It is measured as the percentage of sperms that are moving, and as the percentage of sperms with productive flagellar motion such as rapid, linear, and forward progression.


The posterior filiform portion of the spermatozoon (SPERMATOZOA) that provides sperm motility.


The process of germ cell development in the male from the primordial germ cells, through SPERMATOGONIA; SPERMATOCYTES; SPERMATIDS; to the mature haploid SPERMATOZOA.


An action or movement due to the application of a sudden unexpected stimulus. [GOC:dph]


An activity in which the body is propelled through water by specific movement of the arms and/or the legs. Swimming as propulsion through water by the movement of limbs, tail, or fins of animals is often studied as a form of PHYSICAL EXERTION or endurance.


symbiosis, encompassing mutualism through parasitism

The relationship between two different species of organisms that are interdependent; each gains benefits from the other or a relationship between different species where both of the organisms in question benefit from the presence of the other.


Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions.


Cell membranes associated with synapses. Both presynaptic and postsynaptic membranes are included along with their integral or tightly associated specializations for the release or reception of transmitters.


Membrane-bound compartments which contain transmitter molecules. Synaptic vesicles are concentrated at presynaptic terminals. They actively sequester transmitter molecules from the cytoplasm. In at least some synapses, transmitter release occurs by fusion of these vesicles with the presynaptic membrane, followed by exocytosis of their contents.


The three-part structure of ribbon-like proteinaceous material that serves to align and join the paired homologous CHROMOSOMES. It is formed during the ZYGOTENE STAGE of the first meiotic division. It is a prerequisite for CROSSING OVER.


sense of taste
taste perception
gustation
sensory perception of taste

The ability to detect chemicals through gustatory receptors in the mouth, including those on the TONGUE; the PALATE; the PHARYNX; and the EPIGLOTTIS.


The final phase of cell nucleus division following ANAPHASE, in which two daughter nuclei are formed, the CYTOPLASM completes division, and the CHROMOSOMES lose their distinctness and are transformed into CHROMATIN threads.


The series of events required for an organism to receive a temperature stimulus, convert it to a molecular signal, and recognize and characterize the signal. Thermoception in larger animals is mainly done in the skin; mammals have at least two types of sensor, for detecting heat (temperatures above body temperature) and cold (temperatures below body temperature). [GOC:ai, Wikipedia:Thermoception]


The process whereby calcium salts are deposited in the dental enamel. The process is normal in the development of bones and teeth. (Boucher's Clinical Dental Terminology, 4th ed, p43)


Increased rate of gene expression directed by TRANS-ACTIVATORS.


The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.


Discharge of URINE, liquid waste processed by the KIDNEY, from the body.


myometrial smooth muscle contraction
uterine smooth muscle contraction
myometrium contraction


Any spaces or cavities within a cell. They may function in digestion, storage, secretion, or excretion.


negative regulation of blood vessel size

The physiological narrowing of BLOOD VESSELS by contraction of the VASCULAR SMOOTH MUSCLE.


positive regulation of blood vessel size

The physiological widening of BLOOD VESSELS by relaxing the underlying VASCULAR SMOOTH MUSCLE.


The infective system of a virus, composed of the viral genome, a protein core, and a protein coat called a capsid, which may be naked or enclosed in a lipoprotein envelope called the peplos.


The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its VIRULENCE FACTORS.


The mechanism by which latent viruses, such as genetically transmitted tumor viruses (PROVIRUSES) or PROPHAGES of lysogenic bacteria, are induced to replicate and then released as infectious viruses. It may be effected by various endogenous and exogenous stimuli, including B-cell LIPOPOLYSACCHARIDES, glucocorticoid hormones, halogenated pyrimidines, IONIZING RADIATION, ultraviolet light, and superinfecting viruses.


A general term for diseases caused by viruses.


The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.


visual perception
vision
sensory visual perception

The series of events required for an organism to receive a visual stimulus, convert it to a molecular signal, and recognize and characterize the signal. Visual stimuli are detected in the form of photons and are processed to form an image. [GOC:ai]


The active production and accumulation of VITELLINS (egg yolk proteins) in the non-mammalian OOCYTES from circulating precursors, VITELLOGENINS. Vitellogenesis usually begins after the first MEIOSIS and is regulated by estrogenic hormones.


Restoration of integrity to traumatized tissue.


The female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in human and other male-heterogametic species.


dosage compensation by inactivation of X chromosome

Compensating for the two-fold variation in X-chromosome:autosome ratios between sexes by a global inactivation of all, or most of, the genes on one of the X-chromosomes in the XX sex. [GOC:jl, GOC:mr, GOC:pr, ISBN:0140512888, PMID:11498577, PMID:20622855, Wikipedia:XY_sex-determination_system]


The male sex chromosome, being the differential sex chromosome carried by half the male gametes and none of the female gametes in humans and in some other male-heterogametic species in which the homologue of the X chromosome has been retained.


A tough transparent membrane surrounding the OVUM. It is penetrated by the sperm during FERTILIZATION.


The carbohydrate-rich zone on the cell surface. This zone can be visualized by a variety of stains as well as by its affinity for lectins. Although most of the carbohydrate is attached to intrinsic plasma membrane molecules, the glycocalyx usually also contains both glycoproteins and proteoglycans that have been secreted into the extracellular space and then adsorbed onto the cell surface. (Alberts et al., Molecular Biology of the Cell, 3d ed, p502)


A quiescent state of cells during G1 PHASE.


The period of the CELL CYCLE preceding DNA REPLICATION in S PHASE. Subphases of G1 include "competence" (to respond to growth factors), G1a (entry into G1), G1b (progression), and G1c (assembly). Progression through the G1 subphases is effected by limiting growth factors, nutrients, or inhibitors.


G2 phase of mitotic cell cycle
mitotic G2 phase

The period of the CELL CYCLE following DNA synthesis (S PHASE) and preceding M PHASE (cell division phase). The CHROMOSOMES are tetraploid in this point.


Phase of the CELL CYCLE following G1 and preceding G2 when the entire DNA content of the nucleus is replicated. It is achieved by bidirectional replication at multiple sites along each chromosome.


neuron protrusion
neuron projection
neurite
neuron process

In tissue culture, hairlike projections of neurons stimulated by growth factors and other molecules. These projections may go on to form a branched tree of dendrites or a single axon or they may be reabsorbed at a later stage of development. "Neurite" may refer to any filamentous or pointed outgrowth of an embryonal or tissue-culture neural cell.


A terminal section of a chromosome which has a specialized structure and which is involved in chromosomal replication and stability. Its length is believed to be a few hundred base pairs.


Intracytoplasmic, eosinophilic, round to elongated inclusions found in vacuoles of injured or fragmented neurons. The presence of Lewy bodies is the histological marker of the degenerative changes in LEWY BODY DISEASE and PARKINSON DISEASE but they may be seen in other neurological conditions. They are typically found in the substantia nigra and locus coeruleus but they are also seen in the basal forebrain, hypothalamic nuclei, and neocortex.


The continuous turnover of BONE MATRIX and mineral that involves first an increase in BONE RESORPTION (osteoclastic activity) and later, reactive BONE FORMATION (osteoblastic activity). The process of bone remodeling takes place in the adult skeleton at discrete foci. The process ensures the mechanical integrity of the skeleton throughout life and plays an important role in calcium HOMEOSTASIS. An imbalance in the regulation of bone remodeling's two contrasting events, bone resorption and bone formation, results in many of the metabolic bone diseases, such as OSTEOPOROSIS.


Orientation of intracellular structures especially with respect to the apical and basolateral domains of the plasma membrane. Polarized cells must direct proteins from the Golgi apparatus to the appropriate domain since tight junctions prevent proteins from diffusing between the two domains.


respiratory burst after phagocytosis
metabolic burst after phagocytosis
respiratory burst
metabolic burst
oxidative burst after phagocytosis

A large increase in oxygen uptake by neutrophils and most types of tissue macrophages through activation of an NADPH-cytochrome b-dependent oxidase that reduces oxygen to a superoxide. Individuals with an inherited defect in which the oxidase that reduces oxygen to superoxide is decreased or absent (GRANULOMATOUS DISEASE, CHRONIC) often die as a result of recurrent bacterial infections.


A layer of extracellular matrix found beneath epithelial tissues. It is secreted by epithelial cells and comprised of proteoglycans, laminin and type IV collagen.


establishment of integrated proviral latency

A process by which the virus integrates into the host genome and establishes as a stable provirus or prophage. [GOC:jl]


OBSOLETE. The process in which excision of introns from the primary transcript of messenger RNA (mRNA) is followed by ligation of the two exon termini exposed by removal of each intron, so that mRNA consisting only of the joined exons is produced. [GOC:krc, ISBN:0198506732]


Any of the granules, approximately 32 nm x 48 nm and consisting of highly aggregated phycobiliproteins, that are attached in arrays to the external face of a thylakoid membrane in algae of the phyla Cyanophyta and Rhodophyta, where they function as light-harvesting devices in photosynthesis. Excitation energy in the phycobilisome flows in the sequence: phycoerythrin, phycocyanin, allophycocyanin before passing to the antenna chlorophyll of photosystem II. [GOC:jl, PMID:11734882, Wikipedia:Phycobilisome]


Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a disturbance in organismal or cellular homeostasis, usually, but not necessarily, exogenous (e.g. temperature, humidity, ionizing radiation). [GOC:mah]


The production of light by certain enzyme-catalyzed reactions in cells. [ISBN:0198506732]


OBSOLETE. The process of noncoupled solute translocation or facilitated diffusion. [ISBN:0198506732]


The movement of ions across energy-transducing cell membranes. Transport can be active, passive or facilitated. Ions may travel by themselves (uniport), or as a group of two or more ions in the same (symport) or opposite (antiport) directions.


type I programmed cell death
apoptotic process
programmed cell death
apoptotic programmed cell death
apoptotic cell death
programmed cell death by apoptosis
PCD
RCD

A regulated cell death mechanism characterized by distinctive morphologic changes in the nucleus and cytoplasm, including the endonucleolytic cleavage of genomic DNA, at regularly spaced, internucleosomal sites, i.e., DNA FRAGMENTATION. It is genetically programmed and serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.


protein farnesylation
C-terminal protein farnesylation

The covalent attachment of a farnesyl group to a protein. [GOC:jl]


protein amino acid geranylgeranylation
C-terminal protein geranylgeranylation

The covalent attachment of a geranylgeranyl group to a protein. [GOC:jl]


The covalent addition of prenyl and multiprenyl residues to a macromolecule.


protein prenylation
C-terminal protein prenylation

The covalent attachment of a prenyl group to a protein; geranyl, farnesyl, or geranylgeranyl groups may be added. [GOC:di, ISBN:0198506732]


spliceosome complex
spliceosomal complex location
spliceosome
spliceosome complex location

Organelles in which the splicing and excision reactions that remove introns from precursor messenger RNA molecules occur. One component of a spliceosome is five small nuclear RNA molecules (U1, U2, U4, U5, U6) that, working in conjunction with proteins, help to fold pieces of RNA into the right shapes and later splice them into the message.


A process that changes the nucleotide sequence of mRNA from that of the DNA template encoding it. Some major classes of RNA editing are as follows: 1, the conversion of cytosine to uracil in mRNA; 2, the addition of variable number of guanines at pre-determined sites; and 3, the addition and deletion of uracils, templated by guide-RNAs (RNA, GUIDE, KINETOPLASTIDA).


Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.


intracellular anatomical structure
protoplasm
internal to cell

The organized colloidal complex of organic and inorganic substances (as proteins and water) that constitutes the living nucleus, cytoplasm, plastids, and mitochondria of the cell. It is composed mainly of nucleic acids, proteins, lipids, carbohydrates, and inorganic salts.


The portion of the plasma membrane surrounding the brush border. [GOC:mah]


movement of glucose through a biological system; can be across cell membranes and epithelial layers and also can occur within intracellular compartments and extracellular compartments.


The process whose specific outcome is the progression of a tissue over time, from its formation to the mature structure. [ISBN:0471245208]


A stainable aggregation of protein, lipid or small molecules in the cytoplasm.


Distinct stack of lamellae seen within chloroplasts. Grana contain the pigments, electron transfer compounds, and enzymes essential to the light-dependent reactions of photosynthesis. [ISBN:0140514031]


class switch recombination
isotype switch recombination
isotype switching

Gene rearrangement of the B-lymphocyte which results in a substitution in the type of heavy-chain constant region that is expressed. This allows the effector response to change while the antigen binding specificity (variable region) remains the same. The majority of class switching occurs by a DNA recombination event but it also can take place at the level of RNA processing.


gap junction
communicating junction
zonula communicans
gap junction macula
macula communicans

Connections between cells which allow passage of small molecules and electric current. Gap junctions were first described anatomically as regions of close apposition between cells with a narrow (1-2 nm) gap between cell membranes. The variety in the properties of gap junctions is reflected in the number of CONNEXINS, the family of proteins which form the junctions.


terminal button
synaptic bouton
terminal bouton
presynaptic bouton

The distal terminations of axons which are specialized for the release of neurotransmitters. Also included are varicosities along the course of axons which have similar specializations and also release transmitters. Presynaptic terminals in both the central and peripheral nervous systems are included.


A persistent increase in synaptic efficacy, usually induced by appropriate activation of the same synapses. The phenomenological properties of long-term potentiation suggest that it may be a cellular mechanism of learning and memory.


The process by which antigen is presented to lymphocytes in a form they can recognize. This is performed by antigen presenting cells (APCs). Some antigens require processing before they can be recognized. Antigen processing consists of ingestion and partial digestion of the antigen by the APC, followed by presentation of fragments on the cell surface. (From Rosen et al., Dictionary of Immunology, 1989)


A plastid containing pigments other than chlorophyll, usually yellow and orange carotenoid pigments. [ISBN:0471245208]


Self-replicating cytoplasmic organelles of plant and algal cells that contain pigments and may synthesize and accumulate various substances. PLASTID GENOMES are used in phylogenetic studies.


biosynthetic process
synthesis
anabolism
biosynthesis

The chemical reactions and pathways resulting in the formation of substances; typically the energy-requiring part of metabolism in which simpler substances are transformed into more complex ones. [GOC:curators, ISBN:0198547684]


The elimination by an organism of the waste products that arise as a result of metabolic activity. These products include water, carbon dioxide (CO2), and nitrogenous compounds. [ISBN:0192801023]


The process of generating thrombocytes (BLOOD PLATELETS) from the pluripotent HEMATOPOIETIC STEM CELLS in the BONE MARROW via the MEGAKARYOCYTES. The humoral factor with thrombopoiesis-stimulating activity is designated THROMBOPOIETIN.


A decrease in a behavioral response to a repeated stimulus. This is exemplified by the failure of a person to show a startle response to a loud noise that has been repeatedly presented. [ISBN:0582227089]


Portion of the neuronal cell soma from which the axon originates. [GOC:nln]


The dilated terminal portions of neurosecretory axons constituting the hypothalamohypophyseal tract, found in close proximity to sinusoidal capillaries in the posterior pituitary. Herring bodies consist of aggregates of membrane-bound neurosecretory vesicles where oxytocin or antidiuretic hormone (ADH) are stored prior to release. Each Herring body also contains ATP and either neurophysin I or neurophysin II which bind to oxytocin and ADH, respectively. [ISBN:0199652473, Wikipedia:Herring_bodies]


The intracellular plane, located halfway between the poles of the spindle, where chromosomes align during metaphase of mitotic or meiotic nuclear division. [GOC:mah]


nuclear intermembrane space
perinuclear space

The region between the two lipid bilayers of the nuclear envelope; 20-40 nm wide. [GOC:ai]


A class of nuclear body measuring 20-25 nm in diameter and distributed throughout the interchromatin space, linked together by thin fibrils. They are believed to be storage centers for various snRNAs, snRNPs, serine/arginine-rich proteins and RNA polymerase II. A typical mammalian cell contains 25-50 clusters of interchromatin granules. Interchromatin granule clusters do not contain the heterogeneous nuclear RNA-binding proteins (hnRNPs). [GOC:bf, PMID:10984439]


Extra-nucleolar nuclear domains usually visualized by confocal microscopy and fluorescent antibodies to specific proteins. [GOC:ma, PMID:10330182]


connexon complex location
connexon
connexin complex
connexon complex

An assembly of six molecules of connexin, made in the Golgi apparatus and subsequently transported to the plasma membrane, where docking of two connexons on apposed plasma membranes across the extracellular space forms a gap junction. [PMID:11146276]


belt desmosome
zonula adherens
adhesion belt
zonula adhaerens

A cell-cell adherens junction which forms a continuous belt near the apex of epithelial cells. [ISBN:0815316208]


A cell-substrate junction (attachment structure) found in epithelial cells that links intermediate filaments to extracellular matrices via transmembrane complexes. In vertebrates, hemidesmosomes mediate contact between the basal side of epithelial cells and the basal lamina. In C. elegans, hemidesmosomes connect epithelial cells to distinct extracellular matrices on both the apical and basal cell surfaces. [GOC:kmv, ISBN:0815316208, PMID:20205195]


A cell-cell junction that forms a continuous band around each cell in an epithelium; within the septate junction the membranes of adjacent cells maintain a constant distance of approximately 15 nm; found in arthropods. [ISBN:0815332181, PMID:11700298, PMID:12612641, PMID:20795303, PMID:28636800]


An actin-based protrusion from the apical surface of auditory and vestibular hair cells and of neuromast cells. These protrusions are supported by a bundle of cross-linked actin filaments (an actin cable), oriented such that the plus (barbed) ends are at the tip of the protrusion, capped by a tip complex which bridges to the plasma. Bundles of stereocilia act as mechanosensory organelles. [GOC:ecd, PMID:15661519, PMID:7840137]


A thin sheetlike process extended by the leading edge of a migrating cell or extending cell process; contains a dense meshwork of actin filaments. [ISBN:0815316194]


A membrane projection with related cytoskeletal components at the trailing edge of a cell in the process of migrating or being activated, found on the opposite side of the cell from the leading edge or immunological synapse, respectively. [GOC:add, ISBN:0781735149, PMID:12714569, PMID:12787750]


An apical plasma membrane part that forms a narrow enfolded luminal membrane channel, lined with numerous microvilli, that appears to extend into the cytoplasm of the cell. A specialized network of intracellular canaliculi is a characteristic feature of parietal cells of the gastric mucosa in vertebrates. [GOC:mah, ISBN:0721662544, PMID:10700045]


An extremely narrow tubular channel located between adjacent cells. An instance of this is the secretory canaliculi occurring between adjacent parietal cells in the gastric mucosa of vertebrates. [ISBN:0721662544]


A membrane raft that forms small pit, depression, or invagination that communicates with the outside of a cell and extends inward, indenting the cytoplasm and the cell membrane. Examples include flask-shaped invaginations of the plasma membrane in adipocytes associated with caveolin proteins, and minute pits or incuppings of the cell membrane formed during pinocytosis. Caveolae may be pinched off to form free vesicles within the cytoplasm. [GOC:mah, ISBN:0721662544, PMID:16645198]


A membrane-bounded, cytoplasmic secretory granule found in enzyme-secreting cells and visible by light microscopy. Contain zymogen, an inactive enzyme precursor, often of a digestive enzyme. [GOC:jl, ISBN:0198506732]


membrane-coating granule
keratinosome
lamellar body

A membrane-bounded organelle, specialized for the storage and secretion of various substances (surfactant phospholipids, glycoproteins and acid phosphates) which are arranged in the form of tightly packed, concentric, membrane sheets or lamellae. Has some similar properties to, but is distinct from, a lysosome. [GOC:cjm, GOC:jl, PMID:12243725, Wikipedia:Lamellar_granule]


Dynamic cytoplasmic organelles found in almost all cells. They consist of a central core of LIPIDS surrounded by a phospholipid monolayer studded with surface proteins, and are involved in LIPID METABOLISM and storage.


Q disc
transverse disc
A band
anisotropic disc

The dark-staining region of a sarcomere, in which myosin thick filaments are present; the center is traversed by the paler H zone, which in turn contains the M line. [ISBN:0321204131]


A region of a sarcomere that appears as a light band on each side of the Z disc, comprising a region of the sarcomere where thin (actin) filaments are not overlapped by thick (myosin) filaments; contains actin, troponin, and tropomyosin; each sarcomere includes half of an I band at each end. [ISBN:0321204131]


A relatively pale zone traversing the center of the A band of a sarcomere, visible in relaxed muscle fibers; consists of the central portion of thick (myosin) filaments that are not overlapped by thin (actin) filaments. [GOC:mtg_muscle, ISBN:0321204131]


The midline of aligned thick filaments in a sarcomere; location of specific proteins that link thick filaments. Depending on muscle type the M band consists of different numbers of M lines. [GOC:mtg_muscle, ISBN:0198506732, ISBN:0815316194]


Platelike region of a muscle sarcomere to which the plus ends of actin filaments are attached. [GOC:mtg_muscle, ISBN:0815316194]


Either of the ends of a spindle, where spindle microtubules are organized; usually contains a microtubule organizing center and accessory molecules, spindle microtubules and astral microtubules. [GOC:clt]


An immature form of a centriole or basal body.


A small (70-100 nm) cytoplasmic granule that contains a number of centrosomal proteins; centriolar satellites traffic toward microtubule minus ends and are enriched near the centrosome. [GOC:BHF, PMID:10579718, PMID:12403812]


The bundle of microtubules and associated proteins that forms the core of cilia (also called flagella) in eukaryotic cells and is responsible for their movements. [GOC:bf, GOC:cilia, ISBN:0198547684]


The lipid bilayer surrounding any of the compartments of the Golgi apparatus. [GOC:mah]


Any of the thin, flattened membrane-bounded compartments that form the central portion of the Golgi complex. [GOC:mah]


The lipid bilayer surrounding the endoplasmic reticulum. [GOC:mah]


A type of endoplasmic reticulum (ER) where polyribosomes are present on the cytoplasmic surfaces of the ER membranes. This form of ER is prominent in cells specialized for protein secretion and its principal function is to segregate proteins destined for export or intracellular utilization.


A type of endoplasmic reticulum lacking associated ribosomes on the membrane surface. It exhibits a wide range of specialized metabolic functions including supplying enzymes for steroid synthesis, detoxification, and glycogen breakdown. In muscle cells, smooth endoplasmic reticulum is called SARCOPLASMIC RETICULUM.


smooth endoplasmic reticulum membrane
SER membrane

The lipid bilayer surrounding the smooth endoplasmic reticulum. [GOC:mah]


Stacks of endoplasmic reticulum (ER) membranes containing a high density of nuclear pores, thought to form from excess nuclear membrane components, that have been described in a number of different cells. Annulate lamellar membranes are continuous with and embedded within the ER. [PMID:12631728]


The lipid bilayer surrounding the lysosome and separating its contents from the cell cytoplasm. [GOC:ai]


A lysosome before it has fused with a vesicle or vacuole. [GOC:jl, ISBN:0815316194]


Vacuole formed by the fusion of a lysosome with an organelle (autosome) or with a primary phagosome. [GOC:jl, ISBN:0815316194]


degrading autophagic vacuole
autolysosome
autophagolysosome

A type of secondary lysosome in which a primary lysosome has fused with the outer membrane of an autophagosome. It is involved in the second step of autophagy in which it degrades contents with acidic lysosomal hydrolases. [GOC:sart, NIF_Subcellular:sao8444068431, PMID:19008921]


A type of endosome in which regions of the limiting endosomal membrane invaginate to form internal vesicles; membrane proteins that enter the internal vesicles are sequestered from the cytoplasm. [PMID:11566881, PMID:16533950]


A membrane-bounded vesicle wholly contained within a multivesicular body. [GOC:pde, PMID:21183070]


The lipid bilayer surrounding a microbody. [GOC:mah]


mitochondrion outer membrane
outer mitochondrion membrane
mitochondrial outer membrane

The outer, i.e. cytoplasm-facing, lipid bilayer of the mitochondrial envelope. [GOC:ai]


mitochondrial inner membrane
inner mitochondrial membrane
inner mitochondrion membrane

The inner, i.e. lumen-facing, lipid bilayer of the mitochondrial envelope. It is highly folded to form cristae. [GOC:ai]


Any of the inward folds of the mitochondrial inner membrane. Their number, extent, and shape differ in mitochondria from different tissues and organisms. They appear to be devices for increasing the surface area of the mitochondrial inner membrane, where the enzymes of electron transport and oxidative phosphorylation are found. Their shape can vary with the respiratory state of the mitochondria. [ISBN:0198506732]


The division of a mitochondrion within a cell to form two or more separate mitochondrial compartments. [PMID:11038192]


A sub-structure within the large single mitochondrion of kinetoplastid parasites and which is closely associated with the flagellar pocket and basal body of the flagellum. [GOC:mb]


An supramolecular fiber that consists of an insoluble core of polymerized tropoelastin monomers and a surrounding mantle of microfibrils. Elastic fibers provide elasticity and recoiling to tissues and organs, and maintain structural integrity against mechanical strain. [GOC:BHF, GOC:mah, PMID:20236620]


An intracellular, often complex, membranous structure, sometimes with additional membranous lamellae inside, found in bacteria. They are associated with synthesis of DNA and secretion of proteins. [PMID:31921091, PMID:33327493]


Direct ossification that occurs within mesenchyme or an accumulation of relatively unspecialized cells. [ISBN:0878932437]


Transfer of an organized electrical impulse across the heart to coordinate the contraction of cardiac muscles. The process begins with generation of an action potential (in the sinoatrial node (SA) in humans) and ends with a change in the rate, frequency, or extent of the contraction of the heart muscles. [GOC:dph]


The regulated release of gastric acid (hydrochloric acid) by parietal or oxyntic cells during digestion. [GOC:hjd]


The spontaneous peristaltic movements of the stomach that aid in digestion, moving food through the stomach and out through the pyloric sphincter into the duodenum. [GOC:cy, ISBN:9781416032458, PMID:16139031]


regulation of small intestine emptying
regulation of gastric emptying

Any process that modulates the frequency, rate or extent of any gastric emptying process, the process in which the liquid and liquid-suspended solid contents of the stomach exit through the pylorus into the duodenum. [GOC:sl, PMID:15890336]


A digestive process in which food, usually grass or hay, is swallowed into a multi-compartmented stomach, regurgitated, chewed again, and swallowed again. [GOC:maf, Wikipedia:Rumination]


The regulated release of bile acid, composed of any of a group of steroid carboxylic acids occurring in bile, by a cell or a tissue. [GOC:ecd]


The process in which plasma is filtered through the glomerular membrane which consists of capillary endothelial cells, the basement membrane, and epithelial cells. The glomerular filtrate is the same as plasma except it has no significant amount of protein. [GOC:mtg_cardio, GOC:sart, ISBN:0721643949]


spermatid development
spermatid cell development

The process whose specific outcome is the progression of a spermatid over time, from its formation to the mature structure. [GOC:dph, GOC:go_curators]


The vesicular release of acetylcholine from a presynapse, across a chemical synapse, the subsequent activation of dopamine receptors at the postsynapse of a target cell (neuron, muscle, or secretory cell) and the effects of this activation on the postsynaptic membrane potential and ionic composition of the postsynaptic cytosol. This process encompasses both spontaneous and evoked release of neurotransmitter and all parts of synaptic vesicle exocytosis. Evoked transmission starts with the arrival of an action potential at the presynapse. [GOC:dos, Wikipedia:Cholinergic]


The vesicular release of dopamine. from a presynapse, across a chemical synapse, the subsequent activation of dopamine receptors at the postsynapse of a target cell (neuron, muscle, or secretory cell) and the effects of this activation on the postsynaptic membrane potential and ionic composition of the postsynaptic cytosol. This process encompasses both spontaneous and evoked release of neurotransmitter and all parts of synaptic vesicle exocytosis. Evoked transmission starts with the arrival of an action potential at the presynapse. [GOC:dos, GOC:dph]


A reflex process in which an animal immediately tries to turn over after being placed in a supine position. [GOC:dph, PMID:8635460]


Sensing of noxious mechanical, thermal or chemical stimuli by NOCICEPTORS. It is the sensory component of visceral and tissue pain (NOCICEPTIVE PAIN).


CSF flow
CSF circulation
cerebrospinal fluid flow

The neurological system process driven by motile cilia on ependymal cells of the brain by which cerebrospinal fluid circulates from the sites of secretion to the sites of absorption. In ventricular cavities, the flow is unidirectional and rostrocaudal, in subarachnoid spaces, the flow is multi-directional. [GOC:mgi_curators, PMID:22100360, PMID:24229449]


The reception of a photon by a cell. [GOC:go_curators]


The muscle system process that results in enlargement or overgrowth of all or part of a muscle organ due to an increase in the size of its muscle cells. Physiological hypertrophy is a normal process during development (it stops in cardiac muscle after adolescence) and can also be brought on in response to demand. In athletes cardiac and skeletal muscles undergo hypertrophy stimulated by increasing muscle activity on exercise. Smooth muscle cells in the uterus undergo hypertrophy during pregnancy. [GOC:mtg_muscle]


Formation of differentiated cells and complicated tissue organization to provide specialized functions.


tight junction
zonula occludens
occluding junction
occluding cell junction

Cell-cell junctions that seal adjacent epithelial cells together, preventing the passage of most dissolved molecules from one side of the epithelial sheet to the other. (Alberts et al., Molecular Biology of the Cell, 2nd ed, p22)


The process in which the neutrophil is stimulated by diverse substances, resulting in degranulation and/or generation of reactive oxygen products, and culminating in the destruction of invading pathogens. The stimulatory substances, including opsonized particles, immune complexes, and chemotactic factors, bind to specific cell-surface receptors on the neutrophil.


An amorphous region of electron dense material in the cytoplasm from which the MICROTUBULES polymerization is nucleated. The pericentriolar region of the CENTROSOME which surrounds the CENTRIOLES is an example.


The cell center, consisting of a pair of CENTRIOLES surrounded by a cloud of amorphous material called the pericentriolar region. During interphase, the centrosome nucleates microtubule outgrowth. The centrosome duplicates and, during mitosis, separates to form the two poles of the mitotic spindle (MITOTIC SPINDLE APPARATUS).


The directional growth of organisms in response to gravity. In plants, the main root is positively gravitropic (growing downwards) and a main stem is negatively gravitropic (growing upwards), irrespective of the positions in which they are placed. Plant gravitropism is thought to be controlled by auxin (AUXINS), a plant growth substance. (From Concise Dictionary of Biology, 1990)


The directional growth of an organism in response to an external stimulus such as light, touch, or gravity. Growth towards the stimulus is a positive tropism; growth away from the stimulus is a negative tropism. (From Concise Dictionary of Biology, 1990)


The directional growth of organisms in response to light. In plants, aerial shoots usually grow towards light. The phototropic response is thought to be controlled by auxin (= AUXINS), a plant growth substance. (From Concise Dictionary of Biology, 1990)


Vesicles formed when cell-membrane coated pits (COATED PITS, CELL-MEMBRANE) invaginate and pinch off. The outer surface of these vesicles are covered with a lattice-like network of coat proteins, such as CLATHRIN, coat protein complex proteins, or CAVEOLINS.


Catalysis of a biochemical reaction at physiological temperatures. In biologically catalyzed reactions, the reactants are known as substrates, and the catalysts are naturally occurring macromolecular substances known as enzymes. Enzymes possess specific binding sites for substrates, and are usually composed wholly or largely of protein, but RNA that has catalytic activity (ribozyme) is often also regarded as enzymatic. [GOC:vw, ISBN:0198506732]


A complex and coordinated series of cellular movements that occurs at the end of cleavage during embryonic development of most animals. The details of gastrulation vary from species to species, but usually result in the formation of the three primary germ layers, ectoderm, mesoderm and endoderm. [GOC:curators, ISBN:9780878933846]


secondary metabolite metabolic process
secondary metabolite metabolism
secondary metabolic process

The chemical reactions and pathways resulting in many of the chemical changes of compounds that are not necessarily required for growth and maintenance of cells, and are often unique to a taxon. In multicellular organisms secondary metabolism is generally carried out in specific cell types, and may be useful for the organism as a whole. In unicellular organisms, secondary metabolism is often used for the production of antibiotics or for the utilization and acquisition of unusual nutrients. [GOC:go_curators]


Microbodies which occur in plant cells, and in some eukaryotic microorganisms, and which contain enzymes of the glyoxylate cycle. (Singleton and Stainsbury, Dictionary of Microbiology and Molecular Biology, 2nd ed)


The passage of a leukocyte between the tight junctions of endothelial cells lining blood vessels, typically the fourth and final step of cellular extravasation. [ISBN:0781735149, PMID:14680625, PMID:14708592, PMID:7507411, PMID:8600538]


A sequence of responses that occur when an organism is exposed to excessive heat. In humans, an increase in skin temperature triggers muscle relaxation, sweating, and vasodilation.


An immune response taking place in mucosal tissues, including those of the intestinal tract, nasal and upper respiratory tract, and genital tract. [GO_REF:0000022, GOC:jal, ISBN:0781735149]


A directed change in translational READING FRAMES that allows the production of a single protein from two or more OVERLAPPING GENES. The process is programmed by the nucleotide sequence of the MRNA and is sometimes also affected by the secondary or tertiary mRNA structure. It has been described mainly in VIRUSES (especially RETROVIRUSES); RETROTRANSPOSONS; and bacterial insertion elements but also in some cellular genes.


virion organization
virion assembly and maintenance
viral particle assembly
virus particle assembly
virion assembly
viral assembly

The assembly of VIRAL STRUCTURAL PROTEINS and nucleic acid (VIRAL DNA or VIRAL RNA) to form a VIRUS PARTICLE.


oxidative metabolism
cellular respiration
oxidative metabolic process
aerobic respiration

The metabolic process of all living cells (animal and plant) in which oxygen is used to provide a source of energy for the cell.


The movement of a mast cell within or between different tissues and organs of the body. [GOC:cvs, PMID:24152847]


Blood vessel formation when new vessels emerge from the proliferation of pre-existing blood vessels. [ISBN:0878932453]

blood vessel formation from pre-existing blood vessels


The chemical reactions and pathways involving carbohydrates, any of a group of organic compounds based of the general formula Cx(H2O)y. [GOC:mah, ISBN:0198506732]


The regulated release of hormones, substances with a specific regulatory effect on a particular organ or group of cells. [ISBN:0198506732]


The movement of a neutrophil within or between different tissues and organs of the body. [PMID:1826836]


The directed movement of a neutrophil cell, the most numerous polymorphonuclear leukocyte found in the blood, in response to an external stimulus, usually an infection or wounding. [GOC:jl, ISBN:0198506732]


The directed movement of a lymphocyte in response to an external stimulus. [GOC:hjd, GOC:jid, PMID:12391252]


The compaction of chromatin during apoptosis. [GOC:mah]


Formation of CORPUS LUTEUM. This process includes capillary invasion of the ruptured OVARIAN FOLLICLE, hypertrophy of the GRANULOSA CELLS and the THECA CELLS, and the production of PROGESTERONE. Luteinization is regulated by LUTEINIZING HORMONE.


Direct ossification in which bone formation occurs as result of the direct transformation of non-bone cells into bone cells without cell division. [GO_REF:0000034]


A protein modification process that results in the addition of a carbohydrate or carbohydrate derivative unit to a protein amino acid, e.g. the addition of glycan chains to proteins. [GOC:curators, GOC:pr]