Exam Questions and CORRECT Answers
A-Band - CORRECT ANSWER - one of the transverse bands making up repeated
striations of cardiac and skeletal muscle; region of aligned myosin-containing thick filaments
Absolute Refractory period - CORRECT ANSWER - time during which an excitable
membrane cannot generate an action potential in response to any stimulus
Acetylcholine (ACh) - CORRECT ANSWER - a neurotransmitter released by pre- and
postganglionic parasympathetic neurons, preganglionic sympathetic neurons, somatic neurons,
and some CNS neurons
Acetylcholinesterase - CORRECT ANSWER - enzyme that breaks down acetylcholine
into acetic acid and choline 22
Actin - CORRECT ANSWER - polymers of G-actin that form part of the cell cytoskeleton
and are part of the contractile apparatus of muscle cells; also called microfilaments
Action potential - CORRECT ANSWER - electrical signal propagated by neurons and
muscle cells; an all-or-none depolarization of membrane polarity; has a threshold and refractory
period and is conducted without decrement
Active Zone - CORRECT ANSWER - region within an axon terminal where
neurotransmitter vesicles are clustered prior to secretion
Aerobic metabolism - CORRECT ANSWER - in presence of oxygen
Afferent neuron - CORRECT ANSWER - neuron that carries information from sensory
receptors at its peripheral endings to CNS; cell body lies outside CNS
,Alzheimer's Disease - CORRECT ANSWER - Degradation of neurons associated with the
Ach system. Associated with a decreased amount of Ach in certain areas of the brain. Loss of
postsynaptic neurons that responded to Ach. Results in declining language and perceptual
abilities, confusion, and memory loss
Anaerobic metabolism - CORRECT ANSWER - in the absence of oxygen
Apical membrane - CORRECT ANSWER - the surface of an epithelial cell that faces a
lumen, such as that of the intestines
Astrocyte - CORRECT ANSWER - a form of glial cell that regulates composition of
extracellular fluid around neurons and forms part of the blood-brain barrier
ATP - CORRECT ANSWER - nucleotide that transfers energy from metabolism to cell
functions during its breakdown to ADP and release of Pi
Autocrine - CORRECT ANSWER - chemical messenger secreted into extracellular fluid
that acts upon the cell that secreted it; compare paracrine substance
Axon - CORRECT ANSWER - chemical messenger secreted into extracellular fluid that
acts upon the cell that secreted it; compare paracrine substance
Axon terminal - CORRECT ANSWER - end of axon; forms synaptic or neuroeffector
junction with postjunctional cell
Basolateral membrane - CORRECT ANSWER - sides of epithelial cell other than luminal
surface; also called serosal or blood side of cell
Botulinum toxin (Botox®) - CORRECT ANSWER - clostridium botulinum bacilli toxin
(botulism). Interferes with SNARE proteins at excitatort synapses that activate muscles.
Botilusm is characterized as muscle paralysis.
, Botox injections can help treat face wrinkles, severe sweating, and uncontrollable blinking
Cell - CORRECT ANSWER - the functional unit of living organisms; four broad classes
included epithelial, connective, nervous, and muscle
Cell body dendrite - CORRECT ANSWER - receive info, direct info towards the cell
body. Short branching, dendritic spines where axons can synapse
Central nervous system (CNS) - CORRECT ANSWER - brain and spinal cord
Chemical synapse - CORRECT ANSWER - synapse at which neurotransmitters released
by one neuron diffuse across an extracellular gap to influence a second neuron's activity
Circadian rhythm - CORRECT ANSWER - occurring in an approximately 24 h cycle
Connective tissue - CORRECT ANSWER - one of the four major categories of tissues in
the body; major component of extracellular matrices, cartilage, and bone
Contraction phase: - CORRECT ANSWER - the activation of tension generating sites
within muscle fibers.
Convergence - CORRECT ANSWER - (neuronal) many presynaptic neurons synapsing
upon one postsynaptic neuron;
Creatine phosphate - CORRECT ANSWER - molecule that transfers phosphate and energy
to ADP to generate ATP
Cross-bridge - CORRECT ANSWER - in muscle, myosin projection extending from thick
filament and capable of exerting force on thin filament, causing the filaments to slide past each
other