Module 7

Question 1

accessory nerve

Answer 1

cranial nerve XI extending from brain stem area to the neck muscles through jugular foramen

Question 2

action

Answer 2

major movement associated with a muscle

Question 3

action potential

Answer 3

change in voltage of a cell membrane in response to a stimulus that results in transmission of an electrical signal; unique to neurons and muscle fibers

Question 4

activation gate

Answer 4

part of the voltage-gated Na+ channel that opens when the membrane voltage reaches threshold

Question 5

axon

Answer 5

single process of the neuron that carries an electrical signal/action potential away from the cell body toward a target cell

Question 6

axon hillock

Answer 6

tapering of the neuron cell body that gives rise to the axon

Question 7

axon segment

Answer 7

single stretch of the axon insulated by myelin and bounded by nodes of Ranvier at either end (except for the first, which is after the initial segment, and the last, which is followed by the axon terminal)

Question 8

axon terminal

Answer 8

end of the axon, where there are usually several branches extending toward the target cell

Question 9

axoplasm

Answer 9

cytoplasm of an axon, which is different in composition than the cytoplasm of the neuronal cell body

Question 10

dendrite

Answer 10

one of many branchlike processes that extends from the neuron cell body and functions as a contact for incoming signals/synapses from other neurons or sensory cells

Question 11

depolarization

Answer 11

change in a cell membrane potential from rest toward zero

Question 12

external oblique

Answer 12

superficial abdominal muscle with fascicles that extend inferiorly and medially

Question 13

facial nerve

Answer 13

cranial nerve VII extending from brain stem area to the facial muscles through stylomastoid foramen

Question 14

foramen ovale of the middle cranial fossa

Answer 14

oval-shaped opening in the floor of the middle cranial fossa

Question 15

hyperpolarization

Answer 15

while the K+ channels are open, membrane goes slightly over the resting potential

Question 16

inactivation gate

Answer 16

part of a voltage-gated Na+ channel that closes when the membrane potential reaches +30 mV

Question 17

insertion

Answer 17

end of a skeletal muscle that is attached to the structure (usually a bone) that is moved when the muscle contracts

Question 18

internal oblique

Answer 18

flat, intermediate abdominal muscle with fascicles that run perpendicular to those of the external oblique

Question 19

jugular foramen

Answer 19

irregularly shaped opening located in the lateral floor of the posterior cranial cavity

Question 20

lateral pterygoid

Answer 20

muscle that moves the mandible from side to side

Question 21

linea alba

Answer 21

white, fibrous band that runs along the midline of the trunk

Question 22

masseter

Answer 22

main muscle for chewing that elevates the mandible to close the mouth

Question 23

mastication

Answer 23

chewing

Question 24

mastoid process

Answer 24

large bony prominence on the inferior, lateral skull, just behind the earlobe

Question 25

membrane potential

Answer 25

distribution of charge across the cell membrane, based on the charges of ions

Question 26

nerve

Answer 26

cord-like bundle of axons located in the peripheral nervous system that transmits sensory input and response output to and from the central nervous system

Question 27

neuron

Answer 27

neural tissue cell that is primarily responsible for generating and propagating electrical signals into, within, and out of the nervous system

Question 28

oblique

Answer 28

at an angle

Question 29

orbicularis oculi

Answer 29

circular muscle that closes the eye

Question 30

orbicularis oris

Answer 30

circular muscle that moves the lips

Question 31

origin

Answer 31

end of a skeletal muscle that is attached to another structure (usually a bone) in a fixed position

Question 32

rectus abdominis

Answer 32

long, linear muscle that extends along the midline of the trunk

Question 33

refractory period

Answer 33

time after the initiation of an action potential when another action potential cannot be generated

Question 34

repolarization

Answer 34

return of the membrane potential to its normally negative voltage at the end of the action potential

Question 35

resting membrane potential

Answer 35

the difference in voltage measured across a cell membrane under steady-state conditions, typically -70 mV

Question 36

phrenic nerve

Answer 36

nerve that is connected to the spinal cord at cervical levels 3-5 responsible for the muscle contractions that drive ventilation

Question 37

spinal cord

Answer 37

organ of the central nervous system found within the vertebral cavity and connected with the periphery through spinal nerves; mediates reflex behaviours

Question 38

splenius capitis

Answer 38

neck muscle that inserts into the head region

Question 39

sternocleidomastoid

Answer 39

major muscle that laterally flexes and rotates the head

Question 40

stylomastoid foramen

Answer 40

opening located on inferior skull, between the styloid process and mastoid process

Question 41

styloid process

Answer 41

downward projecting, elongated bony process located on the inferior aspect of the skull

Question 42

synapse

Answer 42

narrow junction across which a chemical signal passes from one neuron to the next, initiating a new electrical signal in the target cell

Question 43

synaptic cleft

Answer 43

small gap between cells in a chemical synapse where neurotransmitter diffuses from the presynaptic element to the postsynaptic element

Question 44

temporalis

Answer 44

muscle that retracts the mandible

Question 45

threshold

Answer 45

membrane voltage at which an action potential is initiated

Question 46

transversus abdominis

Answer 46

muscle that compresses abdominal viscera

Question 47

trigeminal nerve

Answer 47

cranial nerve V extending from brain stem area to the jaw muscles through the foramen ovale

Question 48

voltage-gated channel

Answer 48

ion channel that opens because of a change in the charge distributed across the membrane where it is located

Question 49

zygomaticus major

Answer 49

muscle that draws upper lip upwards