Neuroscience: Exploring The Brain
(Fourth Edition) REAL QUESTIONS AND
ANSWERS
Absolute refractory period - ANS The period of time, measured from the onset of an action
potential, during which another action potential cannot be triggered.
Accommodation – ANS The focusing of light by changing the shape of the eye's lens.
Acetylcholine (ACh) - ANSAn amine that serves as a neurotransmitter at many synapses in the
peripheral and central nervous systems, including the neuromuscular junction.
Actin - ANSA cytoskeletal protein in all cells and the major thin filament protein in a skeletal
muscle fiber; causes muscle contraction by specific chemical interactions with myosin.
Action potential - ANSA brief fluctuation in membrane potential caused by the rapid opening
and closing of voltage-gated ion channels; also known as spike, discharge. Action potentials
sweep nerve impulse, or like a wave along axons to transfer information from one place to
another in the nervous system.
Activational effect – ANS The ability of a hormone to activate reproductive processes or
behaviors in the mature organism.
Active zone - ANSA presynaptic membrane differentiation that is the site of neurotransmitter
release.
Adenylyl cyclase – ANS An that catalyzes the enzyme conversion of adenosine triphosphate
(ATP) to cyclic adenosine monophosphate (cAMP), a second messenger.
adrenal cortex – ANS The outer segment of the adrenal gland; releases cortisol when stimulated
by the pituitary adrenocorticotropic hormone.
adrenal medulla – ANS The inner segment of the adrenal gland, innervated by preganglionic
sympathetic fibers; releases epinephrine.
adrenaline - ANSA catecholamine neurotransmitter synthesized from norepinephrine; also
called epinephrine.
, adrenocorticotropic hormone (ACTH) - ANS hormone released by the anterior pituitary in to
corticotropin-releasing hormone; stimulates the response release of cortisol from the adrenal
gland.
affective aggression - ANSA threatening or defensive form of aggression accompanied by
vocalizations and a high level of ANS activity.
affective disorder - ANSA psychiatric condition characterized by disordered emotions; also called
mood disorder. Examples are major depression and bipolar disorder.
affective neuroscience – ANS The study of the neural basis of mood and emotion.
afferent – ANS An axon coursing toward and innervating a given structure. See also efferent.
after-hyperpolarization – ANS The hyperpolarization that follows strong depolarization of the
membrane; the last part of an action potential, also called undershoot.
agnosia – ANS The inability to recognize objects, even though simple sensory skills appear to be
normal; most commonly caused by damage to posterior parietal areas of the brain.
agoraphobia - ANSA mental disorder characterized by severe anxiety about being in situations in
which escape might be difficult or embarrassing.
alpha motor neuron - ANSA neuron that innervates the extrafusal fibers of skeletal muscle.
amacrine cell - ANSA neuron in the retina of the eye that projects neurites laterally in the inner
plexiform layer.
amino acid - ANSA chemical building block of protein molecules, containing a central carbon
atom, an amino group, a carboxyl group, and a variable R group.
Ammon's horn - ANSA layer of neurons in the hippocampus that sends axons into the fornix.
amnesia - ANSA severe loss of memory or the ability to learn. See also anterograde amnesia,
retrograde amnesia.
AMPA receptor - ANSA subtype of glutamate receptor; a glutamate-gated ion channel that is
permeable to Na+ and K+.
ampulla – ANS The bulge along a semicircular canal, which contains the hair cells that transduce
rotation.
amygdala – ANS An almond-shaped nucleus in the anterior temporal lobe thought to be
involved in emotion and certain types of learning and memory.
anabolism – ANS The biosynthesis of organic molecules from nutritive precursors; also called
anabolic metabolism. See also catabolism.
(Fourth Edition) REAL QUESTIONS AND
ANSWERS
Absolute refractory period - ANS The period of time, measured from the onset of an action
potential, during which another action potential cannot be triggered.
Accommodation – ANS The focusing of light by changing the shape of the eye's lens.
Acetylcholine (ACh) - ANSAn amine that serves as a neurotransmitter at many synapses in the
peripheral and central nervous systems, including the neuromuscular junction.
Actin - ANSA cytoskeletal protein in all cells and the major thin filament protein in a skeletal
muscle fiber; causes muscle contraction by specific chemical interactions with myosin.
Action potential - ANSA brief fluctuation in membrane potential caused by the rapid opening
and closing of voltage-gated ion channels; also known as spike, discharge. Action potentials
sweep nerve impulse, or like a wave along axons to transfer information from one place to
another in the nervous system.
Activational effect – ANS The ability of a hormone to activate reproductive processes or
behaviors in the mature organism.
Active zone - ANSA presynaptic membrane differentiation that is the site of neurotransmitter
release.
Adenylyl cyclase – ANS An that catalyzes the enzyme conversion of adenosine triphosphate
(ATP) to cyclic adenosine monophosphate (cAMP), a second messenger.
adrenal cortex – ANS The outer segment of the adrenal gland; releases cortisol when stimulated
by the pituitary adrenocorticotropic hormone.
adrenal medulla – ANS The inner segment of the adrenal gland, innervated by preganglionic
sympathetic fibers; releases epinephrine.
adrenaline - ANSA catecholamine neurotransmitter synthesized from norepinephrine; also
called epinephrine.
, adrenocorticotropic hormone (ACTH) - ANS hormone released by the anterior pituitary in to
corticotropin-releasing hormone; stimulates the response release of cortisol from the adrenal
gland.
affective aggression - ANSA threatening or defensive form of aggression accompanied by
vocalizations and a high level of ANS activity.
affective disorder - ANSA psychiatric condition characterized by disordered emotions; also called
mood disorder. Examples are major depression and bipolar disorder.
affective neuroscience – ANS The study of the neural basis of mood and emotion.
afferent – ANS An axon coursing toward and innervating a given structure. See also efferent.
after-hyperpolarization – ANS The hyperpolarization that follows strong depolarization of the
membrane; the last part of an action potential, also called undershoot.
agnosia – ANS The inability to recognize objects, even though simple sensory skills appear to be
normal; most commonly caused by damage to posterior parietal areas of the brain.
agoraphobia - ANSA mental disorder characterized by severe anxiety about being in situations in
which escape might be difficult or embarrassing.
alpha motor neuron - ANSA neuron that innervates the extrafusal fibers of skeletal muscle.
amacrine cell - ANSA neuron in the retina of the eye that projects neurites laterally in the inner
plexiform layer.
amino acid - ANSA chemical building block of protein molecules, containing a central carbon
atom, an amino group, a carboxyl group, and a variable R group.
Ammon's horn - ANSA layer of neurons in the hippocampus that sends axons into the fornix.
amnesia - ANSA severe loss of memory or the ability to learn. See also anterograde amnesia,
retrograde amnesia.
AMPA receptor - ANSA subtype of glutamate receptor; a glutamate-gated ion channel that is
permeable to Na+ and K+.
ampulla – ANS The bulge along a semicircular canal, which contains the hair cells that transduce
rotation.
amygdala – ANS An almond-shaped nucleus in the anterior temporal lobe thought to be
involved in emotion and certain types of learning and memory.
anabolism – ANS The biosynthesis of organic molecules from nutritive precursors; also called
anabolic metabolism. See also catabolism.
