Chapter 4

Question 1

membrane potential

Answer 1

the difference in electrical charge between the inside and outside of a cell

Question 2

microelectrodes

Answer 2

extremely fine recording electrodes which are used for intracellular recording

Question 3

neuron at rest’s mV

Answer 3

-70 mV

Question 4

polarized

Answer 4

neuron at resting state with -70mV charge built up across its membrance

Question 5

ions

Answer 5

positively or negatively charged particles

Question 6

resting neurons have more ____ on the inside and more _____ on the outside

Answer 6

more K+ on the inside and more Na+ on the outside

Question 7

ion channels

Answer 7

pores in neural membranes through which specific ions pass

Question 8

of sodium ions out; # of potassium in

Answer 8

3;2

Question 9

postsynaptic potentials (PSPs)

Answer 9

potentials that move the postsynaptic cell’s membrane potential away from the resting state

Question 10

when neurotransmitter molecules bind to postsynaptic receptors they have one or two effects

Answer 10

1. depolarize the receptive membrane (-70 to -67)
2. hyperpolarize the receptive membrane (-70 to -72)

Question 11

excitatory postsynaptic potentials (EPSPs)

Answer 11

graded postsynaptic depolarizations, which increase the likehood that an action potential will be generated

Question 12

inhibitory postsynaptic potentials (IPSPs)

Answer 12

graded postsynaptic depolarizations, which decrease the likehood that an action potential will be generated

Question 13

axon inital segment

Answer 13

between axon and axon hillock and where action potentials occur

Question 14

threshold of excitation

Answer 14

the level of depolarization necessary to generate an action potential; usually about -65mV

Question 15

what have all or nothing responses

Answer 15

action potentials

Question 16

spatial summation

Answer 16

the integration of signals that originate at different sites on the neuron’s membrane

Question 17

temporal summation

Answer 17

the integration of neural signals that occur at different times at the same synapse

Question 18

voltage-gated ion channels

Answer 18

ion channels that open and close in response to changes in the level of membrane potential

Question 19

antidromic conduction

Answer 19

axonal conduction opposite to the normal direction; conduction from axon terminals back toward the cell body

Question 20

orthodromic conduction

Answer 20

axonal conduction in the normal direction - from the cell body toward the terminal buttons

Question 21

saltatory conduction

Answer 21

conduction of an action potential from one node of ranvier to the next along a myelinated axon

Question 22

tripartite synapse

Answer 22

a synapse that involves two neurons and an astroglia

Question 23

neuropeptides

Answer 23

all large neurotransmitters
short amino acid chains

Question 24

synaptic vesicles

Answer 24

-small spherical membranes that store neurotransmitter molecules and release them into the synaptic cleft
-small-molecule neurotransmitters are typically sythesized in the cytoplasm of the terminal button

Question 25

coexistence

Answer 25

the presence of more than one neurotansmitter in the same neuron

Question 26

exocytosis

Answer 26

the process of releasing a neurotransmitter

Question 27

second messenger

Answer 27

a chemical synthesized in a neuron in response to the binding of a neurotransmitter to a metabotropic receptor in its cell membrane

Question 28

autoreceptors

Answer 28

a type of metabotropic receptor located on the presynaptic membrane that bind to their neuron's own neurotransmitters

Question 29

reuptake

Answer 29

the drawing back into the terminal button of neurotransmitter molecules after their release into the synapes; the most common mechanism for deactivating a released neurotransmitter

Question 30

enzymatic degradation

Answer 30

the breakdown of chemicals by enzymes - one of the two mechanisms for deactivating released neurotransmitters

Question 31

gap junctions

Answer 31

narrow spaces between adjacent neurons that are bridged by fine tubular channels containing cytoplasm, through which electrical signals and small molecules can pass readily

Question 32

four most widely studied amino acid neurotransmitter

Answer 32

glutamate, aspartate, glycine, and gamma-aminobutyric acid (GABA)

Question 33

monoamine neurotransmitters

Answer 33

small-molecule neurotransmitters that are synthesizedfrom monoamines and comprise two classes: carecholamines and indolamines

Question 34

four monoamine neurotransmitters

Answer 34

iconic legends dopamine, epinephrine, norepinephrine, serotonin

Question 35

catecholamines

Answer 35

come from tyroshine dopamine, epinephrine, norepinephrine

Question 36

indolamines

Answer 36

come from tryptopham serotonin

Question 37

acetylcholine

Answer 37

a neurotransmitter that is created by the addition of an acetyl group to a choline molecule

Question 38

soluble-gas neurotransmitters

Answer 38

a class of unconventional neurotransmitters that includes nitric oxide and carbon monoxide

Question 39

endocannabinoids

Answer 39

a class of unconventional neurotransmitters that are chemically similar to THC

Question 40

anandamide

Answer 40

the first endogenous endocannabinoid to be discovered and characterized

Question 41

neuropeptide transmitters

Answer 41

peptides that function as neurotransmitters. about 100 have been identified

Question 42

agonists

Answer 42

drugs that facilitate the effects of a particular neurotransmitter

Question 43

antagonists

Answer 43

drugs that inhibit the effects of a particular neurotransmitter

Question 44

receptor blockers

Answer 44

antagonistic drugs that bind to postsynaptic receptors without activating them and block the access of the usual neurotransmitter

Question 45

atropine

Answer 45

a receptor blocker that exerts its antagonistic effect by binding to muscarinic receptors

Question 46

botox

Answer 46

neurotoxin that blocks the release of acetylcholine at neuromuscular junctions