BIO - TERMS - CELL Flashcards
activation-induced cell death
A process by which autoreactive T cells are induced to die if they complete thymic maturation and migrate to the periphery.
adhesion belt
Adherens junctions in epithelia that form a continuous belt (zonula adherens) just beneath the apical face of the epithelium, encircling each of the interacting cells in the sheet.
agonist selection
A process by which T cells are positively selected in the thymus by their interaction with relatively high-affinity ligands.
alarmone
A chemical signal that promotes a cell’s response to environmental stress.
alkaline battery
A dry-cell battery that employs half-reactions in a basic medium.
amphitrichous
Having flagella at both ends of a cell.
Anchorage independence
Th e ability of some cells to grow in the absence of a surface on which to adhere; oft en detected by the ability to form colonies in semisolid media. (Chapter 6)
Animalia
The kingdom composed of multicellular eukaryotes lacking cell walls.
aorta-gonad-mesonephros (AGM)
An embryonic region in which hematopoietic cells arise during development.
Apical domain
The specialized surface of an epithelial cell exposed to the environment. Also called apical surface. (Chapters 2, 9, and 12)
asexual spore
A reproductive cell produced by mitosis and cell division (eukaryotes) or binary fission (actinomycetes).
axon terminal
The end region of an axon, usually a site of synaptic contact with another cell; also called terminal bouton or presynaptic terminal.
B-cell mitogens
Any substance that nonspecifically causes B cells to proliferate.
Basolateral domain
The nonspecialized surface of an epithelial cell that contacts an internal basal lamina or adjacent or underlying cells in the tissue. Also called basolateral surface. (Chapters 2, 9, and 12)
batch production
An industrial process in which cells are grown for a period of time after which the product is collected.
Bcl-6
A transcriptional repressor that opposes differentiation of B cells into plasma cells.
binary fission
Prokaryotic cell reproduction by division into two daughter cells.
binocular competition
A process believed to occur during the development of the visual system whereby the inputs from the two eyes actively compete to innervate the same cells.
binocular visual field
The portion of the visual fi eld viewed by both eyes. bipolar cell In the retina, a cell that connects photoreceptors to ganglion cells.
biogenesis
The theory that living cells arise only from preexisting cells.
Biomarker
Biological parameters at the cellular and multicellular level indicating biochemical changes under environmental stress.
biotechnology
The industrial application of microorganisms, cells, or cell components to make a useful product.
blastoconidium
An asexual fungal spore produced by budding from the parent cell.
BLIMP-1
A transcriptional repressor that promotes B-cell differentiation into plasma cells and suppresses proliferation, and further class switching and affinity maturation.
budding yeast
Following mitosis, a yeast cell that divides unevenly to produce a small cell (bud) from the parent cell.
Calcium channel blockers
Drugs that block voltagegated calcium channels in excitable cells.
callus
(kal′ŭs) Composite mass of cells and extracellular matrix that forms at a fracture site to establish continuity between the bone ends.
cancer stem cells
Rare cancer cells capable of dividing indefinitely.
cartilage
Form of connective tissue composed of cells (chondrocytes) embedded in a matrix rich in type II collagen and chondroitin sulfate proteoglycan.
CCL19
Chemokine made by dendritic cells and stromal cells in T-cell zones of lymph nodes that binds CCR7 and functions to attract naive T cells.
CCL20
Chemokine made by follicle-associated epithelial cells and binds CCR6, recruiting activated T and B cells, NK cells, and dendritic cells into GALT.
CCL21
Chemokine made by dendritic cells and stromal cells in T cell zones of lymph nodes that binds CCR7 and functions to attract naive T cells.
CCL25 (TECK)
Chemokine made by small-intestinal epithelial cells that binds CCR9 to recruit gut-homing T and B cells.
CCL28 (MEC, mucosal epithelial chemokine)
Chemokine made by colonic intestinal cells, salivary gland, and lactating mammary gland cells that binds CCR10 to recruit B lymphocytes producing IgA into these tissues.
CCL9 (MIP-1γ)
Chemokine made by follicle-associated epithelial cells and binds CCR6, recruiting activated T and B cells, NK cells, and dendritic cells into GALT.
CD45RO
An alternatively spliced variant of CD45 that serves as a marker for memory T cells.
CD70
The ligand for CD27 that is expressed on activated dendritic cells and delivers a potent co-stimulatory signal to T cells early in the activation process.
cell culture
Eukaryotic cells grown in culture media; also called tissue culture.
cell determination
Process whereby a cell progressively loses the potential to form other cell types, as development proceeds.
cell signaling
Biochemical processes in a cell responsible for communication and coordination of events.
central (primary) lymphoid organ
Organ in which T or B lymphocytes are produced from precursor cells. In adult mammals, these are the thymus and bone marrow, respectively.
centroblasts
Large, rapidly dividing activated B cells present in the dark zone of germinal centers in follicles of peripheral lymphoid organs.
centrocytes
Small B cells that derive from centroblasts in the germinal centers of follicles in peripheral lymphoid organs; they populate the light zone of the germinal center.
cerebellar granule cell
A neuron in the cerebellar cortex that receives input from mossy fibers and gives rise to parallel fibers that innervate Purkinje cells. Plasticity of the synapses between granule cells and Purkinje cells is believed to be important for motor learning.
Checkpoint
A mechanism that halts progression through the eukaryotic cell cycle.
chondroblast
(kon′drō-blast) A dividing cell in cartilage, which produces the cartilage matrix.
chondrocyte
(kon′drō-sı̄t) Mature, nondividing cartilage cell.
ciliary escalator
Ciliated mucosal cells of the lower respiratory tract that move inhaled particulates away from the lungs.
climbing fiber
An axon of an inferior olive neuron that innervates a Purkinje cell of the cerebellum. Climbing fiber activity is an important trigger for LTD, a form of synaptic plasticity believed to be important for motor learning.
clue cells
Sloughed-off vaginal cells covered with Gardnerella vaginalis.
coenocytic hypha
A fungal filament that is not divided into uninucleate cell-like units because it lacks septa.
color-opponent cell
A cell in the visual system with an excitatory response to wavelengths of light of one color and an inhibitory response to wavelengths of another color; the color pairs that cancel each other are red–green and blue–yellow.
columnar
(kol-ŭm′năr) Relating to epithelial cells that are taller than they are wide.
committed precursor
Cell derived from a stem cell that divides for a limited number of times before terminally differentiating; also known as a transit amplifying cell.
common lymphoid progenitor (CLP)
Stem cell that can give rise to all the types of lymphocytes with the exception of innate lymphoid cells (ILCs).
contractile ring
Ring containing actin and myosin that forms under the surface of animal cells undergoing cell division. Contracts to pinch the two daughter cells apart.
convergent extension
Rearrangement of cells within a tissue that causes it to extend in one dimension and shrink in another.
cortical plate
A cell layer of the immature cerebral cortex containing undifferentiated neurons.
cuboidal
(kū-boy′dăl) Relating to cells that are cube-shaped.
CXCL12 (SDF-1)
Chemokine produced by stromal cells in the dark zone of the germinal center that binds CXCR4 expressed by centroblasts.
CXCL13
Chemokine produced in the follicle and the light zone of the germinal center that binds CXCR5 expressed on circulating B cells and centrocytes.
cytoarchitecture
The arrangement of neuronal cell bodies in various parts of the brain.
cytoplasmic streaming
The movement of cytoplasm in a eukaryotic cell.
Damage-associated molecular patterns
Host components that are released upon cellular damage. (Chapter 3)
dark-field microscopy
Type of light microscopy in which oblique rays of light focused on the specimen do not enter the objective lens, but light that is scattered by components in the living cell can be collected to produce a bright image on a dark background.
Daughter cell
A product of cell division.
DC-SIGN
A lectin on the dendritic-cell surface that binds ICAM-3 with high affinity.
degranulation
The release of contents of secretory granules from mast cells or basophils during anaphylaxis.
delayed hypersensitivity
Cell-mediated hypersensitivity.
dendritic epidermal T cells (dETCs)
A specialized class of γ:δ T cells found in the skin of mice and some other species, but not humans. They express Vγ5:Vδ1 and may interact with ligands such as Skint-1 expressed by keratinocytes.
Determination
Process by which undifferentiated cells in an embryo become committed to develop into specific cell types, such as neuron, fibroblast, and muscle cell.
differential centrifugation
Separation of cell organelles or other particles of different size by their different rates of sedimentation in a centrifugal field.
diploid cell line
Eukaryotic cells grown in vitro.
Diploid cell strains
Cell cultures that consist of a homogeneous population of a single type and that can divide up to 100 times before dying. (Chapter 2)
direct microscopic count
Enumeration of cells by observation through a microscope.
direction selectivity
The property of cells in the visual system that respond only when stimuli move within a limited range of directions.
distributed memory
The concept that memories are encoded by widespread synaptic modifications of many neurons, not by a single synapse or cell.
DN1, DN2, DN3, DN4
Substages in the development of CD4+CD8+ double-positive T cells in the thymus. Rearrangement of the TCRβ-chain locus starts at DN2 and is completed by DN4.
donor lymphocyte infusion (DLI)
Transfer of mature lymphocytes (i.e., T cells) from donor into patients during bone marrow transplantation for cancer treatment to help eliminate residual tumor.
dorsal horn
The dorsal region of the spinal cord containing neuronal cell bodies.
E-cadherin
Integrin expressed by epithelial cells important in forming the adherens junctions between adjacent cells.
effector caspases
Intracellular proteases that are activated as a result of an apoptotic signal and mediate the cellular changes associated with apoptosis. To be distinguished from initiator caspases, which act upstream of effector caspases to initiate the caspase cascade.
Embryoid bodies
Masses of differentiated and undifferentiated cells derived from embryonic stem cells.
endomysium
(en′dō-miz′ē-ŭm, -mis′ē-ŭm) Areolar connective tissue layer surrounding a muscle cell or fiber.
endosymbiotic theory
A model for the evolution of eukaryotes which states that organelles arose from prokaryotic cells living inside a host prokaryote.
Energy charge
A measure for the energy status of a cell.
enteroadherent
Escherichia coli Referring to multiple strains of E. coli capable of attachment to, and infection and destruction of cells of the intestinal microvilli, causing colitis and diarrheagenic diseases.
ependymal
(ep-en′di-mal) Relating to the cellular lining of the brain ventricles and central canal of the spinal cord; assists in production and circulation of CSF.
ependymal cell
A type of glial cell that provides the lining of the brain’s ventricular system.
excitability
The ability of a cell to respond to a stimulus.
excitation–contraction coupling
The physiological process by which the excitation of a muscle cell leads to its contraction.
executioner caspases
Apoptotic caspases that catalyze the widespread cleavage events during apoptosis that kill the cell.
Extracellular
Outside the cells.
extracellular fluid (ECF)
Fluid located outside of cells; plasma and interstitial fluid.
extracellular pathogens
Pathogens that disturb host cells and can cause serious disease without replicating in host cells.
fate map
Representation showing which cell types will later derive from which regions of a tissue; e.g. from the blastula.
fission yeast
Following mitosis, a yeast cell that divides evenly to produce two new cells.
flow cytometry
A method of counting cells using a flow cytometer, which detects cells by the presence of a fluorescent tag on the cell surface.
fluorescence-activated cell sorter (FACS)
A modification of a flow cytometer that counts and sorts cells labeled with fluorescent antibodies.
Foci
(plural) Clusters of cells that are derived from a single progenitor and share properties, such as unregulated growth, that cause them to pile up on one another. One such cluster is called a focus. (Chapter 2)
G1-cyclin
Cyclin present in the G1 phase of the eukaryotic cell cycle. Forms complexes with Cdks that help govern the activity of the G1/S-cyclins, which control progression to S phase.
G1/S-cyclin
Cyclin that activates Cdks in late G1 of the eukaryotic cell cycle and thereby helps trigger progression through Start, resulting in a commitment to cell-cycle entry. Its level falls at the start of S phase.
gametocyte
A male or female protozoan cell.
ganglion cell layer
A layer of the retina closest to the center of the eye, containing ganglion cells.
Gastrula
An early animal embryo consisting of two layers of cells; an embryological stage following the blastula.
Germ plasm
The hereditary material transmitted to the offspring through the germ cells.
germ-line cell
A type of animal cell that is formed early in embryogenesis and may multiply by mitosis or produce by meiosis cells that develop into gametes (egg or sperm cells).
Germline mutation
Mutation arising in the cell lineage that gives rise to gametes.
gland
Organ or individual cells that secrete a substance.
granulocyte/macrophage (GM) progenitor cell
Committed progenitor cell in the bone marrow that gives rise to neutrophils and macrophages.
gray matter
Brain or spinal cord tissue composed of neuron cell bodies, dendrites, and unmyelinated axons.
group 1 ILCs (ILC1s)
The subtype of innate lymphoid cells (ILCs) characterized by IFN-γ production.
Hemoglobin S
Sickle cell hemoglobin.
heterocyst
A large cell in certain cyanobacteria; the site of nitrogen fixation.
high-energy bond
Cellular chemical bond (normally phosphate) by which energy is stored and subsequently released to drive a biochemical reaction.