Chapter 5

Question 1

acetylcholine (Ach)

Answer 1

First neurotransmitter discovered in the PNS and CNS; activates skeletal muscles in the SNS; may either excite or inhibit internal organs in the ANS.

Question 2

epinephrine (EP, or adrenaline)

Answer 2

Chemical messenger that acts as a neurotransmitter in the CNS and as a hormone to mobilize the body for fight or flight during times of stress.

Question 3

norepinephrine (NE, or noradrenaline)

Answer 3

Neurotransmitter that accelerates heart rate in mammals; found in the brain and in the sympathetic division of the ANS.

Question 4

neurotransmitter

Answer 4

Chemical with an excitatory or inhibitory effect when released by a neuron onto a target.

Question 5

Parkinson disease

Answer 5

Motor system disorder correlated with dopamine loss in the substantia nigra; characterized by tremors, muscular rigidity, and reduction in voluntary movement.

Question 6

dopamine (DA)

Answer 6

Amine neurotransmitter involved in coordinating movement, attention, learning, and in reinforcing behaviors.

Question 7

synaptic vesicle

Answer 7

Membranous compartment that encloses a quantum of neurotransmitter.

Question 8

synaptic cleft

Answer 8

Gap separating the neuronal presynaptic membrane from the postsynaptic membrane.

Question 9

chemical synapse

Answer 9

Junction at which messenger molecules are released when stimulated by an action potential.

Question 10

presynaptic membrane

Answer 10

Axon terminal membrane on the transmitter, or output, side of a synapse.

Question 11

postsynaptic membrane

Answer 11

Membrane on the transmitter, or input, side of a synapse.

Question 12

storage granule

Answer 12

Membranous compartment that holds several vesicles containing a neurotransmitter.

Question 13

gap junction (electrical synapse)

Answer 13

Area of contact between adjacent cells in which ion channels form a pore that allows ions to pass directly from one cell to the next.

Question 14

transporter

Answer 14

Protein molecule that pumps substances across a membrane.

Question 15

transmitter-activated receptor

Answer 15

Protein that has a binding site for a specific neurotransmitter and is embedded in the membrane of a cell.

Question 16

autoreceptor

Answer 16

Self-receptor in a neuronal membrane; that is, it responds to the same transmitter released by the neuron.

Question 17

quantum (pl. quanta)

Answer 17

Amount of neurotransmitter, equivalent to the content of a single synaptic vesicle, that produces a just-observable change in postsynaptic electric potential.

Question 18

reuptake

Answer 18

Deactivation of a neurotransmitter when membrane transporter proteins bring the transmitter back into the presynaptic axon terminal for reuse.

Question 19

small-molecule transmitter

Answer 19

Quick-acting neurotransmitter synthesized in the axon terminal from products derived from the diet.

Question 20

histamine (H)

Answer 20

Neurotransmitter that controls arousal and waking; can cause the constriction of smooth muscles; when activated in allergic reactions, constricts airway and contributes to asthma.

Question 21

rate-limiting factor

Answer 21

Any chemical in limited supply that restricts the pace at which another chemical can be synthesized.

Question 22

serotonin (5-Ht)

Answer 22

Amine neurotransmitter; helps to regulate mood and aggression, appetite and arousal, perception of pain, and respiration.

Question 23

glutamate (Glu)

Answer 23

Amino acid neurotransmitter; typically excites neurons.

Question 24

gamma-aminobutyric acid (GABA)

Answer 24

Amino acid neurotransmitter; typically inhibits neurons.

Question 25

neuropeptide

Answer 25

Short (fewer than 100), multifunctional amino acid chain; acts as a neurotransmitter and can act as a hormone; may contribute to learning.

Question 26

endocannabinoid

Answer 26

Class of lipid neurotransmitters, including anandamide and 2-AG, synthesized at the postsynaptic membrane to act on receptors at the presynaptic membrane; affects appetite, pain, sleep, mood, memory, anxiety, and the stress response.

Question 27

nitric oxide (NO)

Answer 27

Gaseous neurotransmitter; acts, for example, to dilate blood vessels, aid digestion, and activate cellular metabolism.

Question 28

carbon monoxide (CO)

Answer 28

Gaseous neurotransmitter; activates cellular metabolism.

Question 29

hydrogen sulfide (H2s)

Answer 29

Gaseous neurotransmitter; slows cellular metabolism.

Question 30

ionotropic receptor

Answer 30

Embedded membrane protein; acts as (1) a binding site for a neurotransmitter and (2) a pore that regulates ion flow to directly and rapidly change membrane voltage.

Question 31

metabotropic receptor

Answer 31

Embedded membrane protein with a binding site for a neurotransmitter linked to a G protein; can affect other receptors or act with second messengers to affect other cellular processes, including opening a pore.

Question 32

G protein

Answer 32

Guanyl nucleotide–binding protein coupled to a metabotropic receptor; when activated, binds to other proteins.

Question 33

subunit

Answer 33

Protein molecule that assembles with other protein molecules.

Question 34

second messenger

Answer 34

Chemical that initiates a biochemical process when activated by a neurotransmitter (the first messenger).

Question 35

cholinergic neuron

Answer 35

Neuron that uses acetylcholine as its main neurotransmitter; cholinergic applies to any neuron that uses ACh as its main transmitter.

Question 36

activating system

Answer 36

Neural pathways that coordinate brain activity through a single neurotransmitter; its cell bodies lie in a brainstem nucleus; axons are distributed through a wide CNS region.

Question 37

Alzheimer disease

Answer 37

Degenerative brain disorder related to aging; first appears as progressive memory loss and later develops into generalized dementia.

Question 38

schizophrenia

Answer 38

Behavioral disorder characterized by delusions, hallucinations, disorganized speech, blunted emotion, agitation or immobility, and a host of associated symptoms.

Question 39

noradrenergic neuron

Answer 39

From adrenaline, Latin for epinephrine; a neuron containing norepinephrine.

Question 40

major depression

Answer 40

Mood disorder characterized by prolonged feelings of worthlessness and guilt, the disruption of normal eating habits, sleep disturbances, a general slowing of behavior, and frequent thoughts of suicide.

Question 41

mania

Answer 41

Disordered mental state of extreme excitement.

Question 42

obsessive-compulsive disorder (OcD)

Answer 42

Behavior characterized by compulsively repeated acts (such as hand washing) and repetitive, often unpleasant, thoughts (obsessions).

Question 43

learning

Answer 43

Relatively permanent change in behavior that results from experience.

Question 44

habituation

Answer 44

Learned behavior in which the response to a stimulus weakens with repeated presentations.

Question 45

sensitization

Answer 45

Learned behavior in which the response to a stimulus strengthens with repeated presentations.

Question 46

posttraumatic stress disorder (PtsD)

Answer 46

Syndrome characterized by physiological arousal associated with recurrent memories and dreams arising from a traumatic event that occurred months or years earlier.