Nervous system vocab

Question 1

stimulus

Answer 1

A change in an organism’s surroundings that causes the organism to react

Question 2

response

Answer 2

An action or change in behavior that occurs as a result of a stimulus.

Question 3

neuron

Answer 3

cells of the nervous system specialized to transmit mes-
sages throughout the body

Question 4

soma

Answer 4

The cell body of a neuron which contains most of the cell’s organelles

Question 5

dendrites

Answer 5

Branchlike parts of a neuron that are specialized to receive
information

Question 6

axon

Answer 6

Long nerve fiber that conducts impulses away from the cell
body of the neuron

Question 7

myelin

Answer 7

a white fatty substance that insulates and protects the axon

Question 8

synapse

Answer 8

Location at which a neuron can transfer an impulse to another cell

Question 9

neurotransmitter

Answer 9

Chemical messengers that cross the synaptic gaps between neurons

Question 10

glial cells

Answer 10

Cells in the nervous system that support, nourish, and protect neurons

Question 11

membrane potential

Answer 11

the difference in electric potential between the two sides
of a cell membrane

Question 12

action potential

Answer 12

Reversal of charges across the cell membrane of a neuron; also called a nerve impulse

Question 13

depolarization

Answer 13

loss or reduction of negative membrane potential (less negative charge inside cell than outside)

Question 14

repolarization

Answer 14

Movement of the membrane potential to the initial resting
(polarized) state; K+ moves out of axon

Question 15

sensory neuron

Answer 15

The nerve cell that carries afferent impulses from a sense
receptor to the brain or spinal cord

Question 16

interneuron

Answer 16

Located in the CNS; transmits impulses between neurons;
completes pathways between afferent and efferent neu-
rons

Question 17

motor neuron

Answer 17

a neuron that sends an efferent impulse to a muscle or
gland, causing the muscle or gland to react

Question 18

central nervous system

Answer 18

the brain and spinal cord

Question 19

peripheral nervous system

Answer 19

The network of afferent and efferent nerves that connects
the brain and spinal cord to other parts of the body

Question 20

cerebrum

Answer 20

Area of the brain responsible for all voluntary activities of the body

Question 21

cerebellum

Answer 21

posterior part of the brain that coordinates muscle movements and maintains balance

Question 22

brain stem

Answer 22

Located at the base of the brain and controls involuntary
actions; midbrain, pons and medulla oblongata

Question 23

sympathetic nervous system

Answer 23

the division of the autonomic nervous system that arouses
the body, mobilizing its energy during a flight or fight
response

Question 24

parasympathetic nervous system

Answer 24

the division of the autonomic nervous system that calms
the body, conserving its energy