B Flashcards
B Cells
Lymphocytes that are produced in the bone marrow (mammals) and bursa of Fabricus (birds), recognized by their expression of B cell receptors that bind to antigens.
Baroreceptor
A receptor that senses pressure (by sensing the resulting stretch on the cell membrane).
Baroreceptor Reflex
A homeostatic feedback loop that regulates blood pressure. Pressure sensors in the heart and arterial system detect changes in blood pressure and send sensory feedback to the central nervous system that causes physiological responses that
return blood pressure back to the normal range.
Basal Lamina
The extracellular matrix underlying a sheet of epithelial cells; part of the connective tissue formed largely by fibroblasts.
Basal Metabolic Rate (BMR)
see also resting metabolic rate, standard metabolic rate
The metabolic rate of a homeothermic animal at rest, at a thermal neutral temperature, and post-absorptive.
Basal Nuclei
Interconnected groups of gray matter within the mammalian brain.
Base
A molecule that accepts a proton, or otherwise causes a reduction in proton concentration through effects on the dissociation of water.
Basilar Membrane
The location of the auditory hair cells in the mammalian cochlea.
Basophil
A type of white blood cell that releases histamine; involved in the vertebrate immune response.
Batch Reactor
A chemical reactor in which nutrients enter and exit through the same
opening; nutrients are retained in the reactor and digested; the undigested material is then expelled, and replaced by another batch of nutrients to be processed.
Behavioral Thermoregulation
The use of behavior to control the body temperature of a poikilotherm, or to reduce the costs of thermoregulation for a homeotherm.
Beta-Oxidation (β-oxidation)
Pathway of fatty acid catabolism that produces acetyl CoA and reducing equivalents.
Beta-Sheet (β-sheet)
Protein folding pattern in which stretches of amino acids are aligned along another amino acid stretch. This secondary structure is stabilized by hydrogen bonds.
Bicuspid Valve (also called the mitral valve)
The valve between the left atrium and the left ventricle of the mammalian
heart.
Bilateral Symmetry
A body form in which the body can be divided by a single plane such that the right and left sides are approximate mirror images.
Bile
A thick, yellow-green fluid composed of salts, pigments, and lipids produced by the liver and stored by the gallbladder; when released into the small intestine it neutralizes gastric acid and aids in the digestion of nutrients, particularly lipids.
Bile Duct
The connection between the liver and
the small intestine.
Bile Pigments
Nondigestible breakdown products of porphyrins, including the hemes found in hemoglobin and cytochromes.
Bile Salts
Cholic acid conjugated with amino acids, primarily glycine and taurine; assist in emulsification of lipid within the small intestine.
Binocular Vision
The ability to compare the images coming from two eyes to produce three-dimensional perception.
Binocular Zone
The area of overlap between the right and left visual fields of a vertebrate that
allows depth perception.
Biogenic Amine
A class of neurotransmitters derived from amino acids including the catecholamines and dopamine.
Bioluminescence
The production of light by living organisms.
Bipolar Neuron
A neuron with two main processes leading from the cell body, one of which conveys signals toward the cell body, and one of which conveys signals away from
the cell body.
Blastema
A mass of cells that can proliferate and differentiate to regenerate damaged tissues or organs.