3 Key terms Nervous System & Senses MT

Question 1

action potential

Answer 1

a nerve impulse; a rapid change in membrane potential that involves depolarization and repolarization

Question 2

brain stem

Answer 2

the portion of the brain between the diencephalon and spinal cord that contains the midbrain, pons, and medulla oblongata

Question 3

cerebellum

Answer 3

second largest part of the human brain, located posterior to the pons and medulla oblongata, and involved in the coordination of muscular movements

Question 4

diencephalon

Answer 4

part of the brain between the cerebral hemispheres and the midbrain; includes the thalamus, hypothalamus, and epithalamus

Question 5

myelin

Answer 5

white, fatty substance that surrounds many nerve fibers

Question 6

neurilemma

Answer 6

the layer of cells that surrounds a nerve fiber in the PNS and, in some cases, produces myelin

Question 7

cerebrum

Answer 7

the largest and uppermost part of the human brain; concerned with consciousness, learning, memory, sensations, and voluntary movements

Question 8

salutatory conduction

Answer 8

process in which a nerve impulse travels along a myelinated nerve fiber by jumping from one node of Ranvier to the next

Question 9

synapse

Answer 9

the region of communication between two neurons

Question 10

threshold stimulus

Answer 10

minimum level of stimulation that is required to start a nerve impulse or muscle contraction; also called liminal stimulus