Chapter 10

Question 1

action potential

Answer 1

Question 2

trigger zone

Answer 2

zone at the first part of an axon that contains many voltage-gated sodium channels

Question 3

absolute refractory period

Answer 3

when threshold stimulus does not start another action potential

Question 4

relative refractory period

Answer 4

when stronger threshold stimulus can start another action potential

Question 5

hyperpolarization

Answer 5

cell membrane becomes more negative

Question 6

depolarization

Answer 6

cell membrane becomes less negative

Question 7

saltatory conduction

Answer 7

process by which myelinated axons transmit impulses; is faster than impulse conduction along unmyelinated axons

Question 8

impulse conduction

Answer 8

speed of conduction varies on different types of neurons

thick fibers transmit faster than thin fibers

Question 9

repolarization

Answer 9

returning membrane to normal resting state?

Question 10

threshold

Answer 10

: level of potential at which an action potential is triggered in a neuron

Question 11

synaptic potential

Question 12

receptors

Question 13

excitatory postsynaptic potential

Answer 13

graded

depolarizes the membrane of postsynaptic neuron

action potential of postsynaptic neuron becomes more likely

Question 14

inhibitory postsynpatic potential

Answer 14

graded

hyperpolarizes membrane of postsynaptic neuron

ction potential less likely

Question 15

somatic nervous system

Question 16

autonomic nervous system

Question 17

neurofibrils

Question 18

chromatophilic substance (Nissl bodies)

Question 19

synaptic cleft

Question 20

sensory receptors

Question 21

summation

Answer 21

when EPSPs and IPSPs are added together

more EPSPs lead to greater probability of an action potential

usually occurs at trigger zone

Question 22

neuropeptides

Answer 22

short-chain polypeptides that act as neurotransmitters

includes:

• enkphalins, endorphins: in CNS; generally inhibitory; reduce pain by inhibiting substance P release
• substance P: in PNS; excitatory; responsible for pain perception

Question 23

neuromodulator

Question 24

monoamine oxidase

Question 25

acetylcholinesterase

Question 26

neuronal pools

Answer 26

groups of interneurons that make synaptic connections with each other and work together to perform a common function

receives input from other neurons and generates output to other neurons

facilitation may occur

Question 27

facilitation

Question 28

convergence

Answer 28

one neuron receives input from several neurons, representing information from different types of sensory receptors

allows nervous system to collect, process, and respond to information

makes it possible for a neuron to sum impulses from different sources

Question 29

divergence

Answer 29

one neuron sends impulses to several

can amplify an impulse

impulse from single neuron in CNS can be amplified to activate enough motor units needed for muscle contraction

Question 30

What are the two types of cells in nervous tissue?

Answer 30

neuroglia and neurons

Question 31

astrocyte

astr-

Answer 31

starlike

Question 32

axon

ax-

Answer 32

axle

Question 33

bipolar neuron

bi-

Answer 33

two

Question 34

dendrite

dendr-

Answer 34

tree

Question 35

ependyma

ependym-

Answer 35

tunic

Question 36

neurilemma

-lemm

Answer 36

rind or peel

Question 37

motor neuron

moto-

Answer 37

moving

Question 38

multipolar neuron

multi-

Answer 38

many

Question 39

oligodendrocyte

oligo-

Answer 39

few

Question 40

peripheral nervous system

peri-

Answer 40

all around

Question 41

saltatory conduction

saltator-

Answer 41

a dancer

Question 42

sensory neuron

sens-

Answer 42

feeling

Question 43

synapse

syn-

Answer 43

together

Question 44

unipolar neuron

uni-

Answer 44

one