Chapter 13

Question 1

What are motor endings?

Answer 1

An element of the PNS that active effectors by releasing neurotransmitters

Question 2

What do motor endings do?

Answer 2

Make something happen

Question 3

What are the 4 steps of excitation

Answer 3

1.) Movement of Na+ and K+ across a membrane
2.) The muscle cell depolarizes
3.) The excitation triggers an action potential
4.) The muscle contracts

Question 4

What level does innervation of skeletal muscle take place at

Answer 4

The neuromuscular junction

Question 5

What neurotransmitter gets released in innervation of skeletal muscle

Answer 5

ACh

Question 6

What is simpler and slower: Autonomic motor endings and visceral effectors or somatic junctions

Answer 6

Autonomic motor endings and visceral effectors

Question 7

What do branches in visceral muscles and glands form

Answer 7

synapses “en passant” (in passing) through varicosities

Question 8

How do neurotransmitters in visceral muscles and glands act

Answer 8

Indirectly through second messenger systems

Question 9

What are the neurotransmitters involved in visceral muscles and glands

Answer 9

ACh and norepinephrine

Question 10

What are the 3 motor control levels in skeletal muscle (lowest to highest)

Answer 10

Segmental, projection, precommand

Question 11

What does the segmental level control

Answer 11

Reflexes and spinal cord circuits

Question 12

What are central pattern generators (CPGs)

Answer 12

Segmental circuits that activate networks of ventral horn neurons to stimulate specific groups of muscle

Question 13

What does the projection level do

Answer 13

Sends information to the lower motor neurons and lets higher levels know what is happening

Question 14

What anatomy is a part of the projection level

Answer 14

Precentral gyrus, cortex, brain stem

Question 15

What is the cortex in charge of on the projection level of motor control

Answer 15

Initiates direct systems, voluntary movement, through upper motor neurons

Question 16

What is the brain stem in charge of on the projection level of motor control

Answer 16

Oversees indirect systems, reflexes and CPG activity, through motor areas

Question 17

What anatomy is a part of the precommand level

Answer 17

Cerebellum and basal nuclei

Question 18

What is the job of the precommand level

Answer 18

Control the outputs of the cortex and brain stem

Question 19

What does the precommand level do for activity

Answer 19

Determines if activity will start or stop

Question 20

What does the cerebellum do on the precommand level of motor control

Answer 20

1.) Acts on motor pathways through projection areas in the brain stem
2.) Acts on motor cortex through the thalamus

Question 21

What does the basal nuceli do on the precommand level of motor control

Answer 21

Acts to inhibit motor centers

Question 22

What are reflexes

Answer 22

a rapid, predictable, involuntary motor response to a given stimulus

Question 23

What are the two categories of reflexes

Answer 23

Autonomic and somatic

Question 24

What are autonomic reflexes

Answer 24

Reflexes that involve smooth muscle, cardiac muscle, and glands

Question 25

Examples of autonomic reflexes

Answer 25

sweat, increase in heart rate, salivation

Question 26

What are somatic reflexes

Answer 26

reflexes that involve skeletal muscle that are quick

Question 27

Examples of somatic reflexes

Answer 27

shiver, knee jerk, cough, muscle strech

Question 28

What does a reflex arc describe

Answer 28

how actions happen

Question 29

What are the steps to a reflex arc

Answer 29

1.) receptor picks up a stimulus 2.) sensory neurons carry info to the CNS in action potentials 3.) Integrate synapse in the CNS 4.) Motor neuron carries AP away from the CNS 5.) An effector gives a response

Question 30

What is the muscle stretch reflex used for

Answer 30

to make sure that a muscle stays at the same length

Question 31

Why do alpha and motor neurons stimulate together

Answer 31

So the muscle spindle responds at various muscle lengths

Question 32

Intrafusal muscle fibers

Answer 32

skeletal muscle cells inside the spindle

Question 33

What does sensory neuron type 1 do

Answer 33

respond to stretch and speed

Question 34

What does sensory neuron type 2 do

Answer 34

respond to stretch degree/amount

Question 35

What are the events of the muscle stretch reflex

Answer 35

1.) The muscle stretch activates the spindle, increasing AP's to the CNS through the sensory neuron 2.) Sensory neurons synapse with alpha motor neurons of the stretched muscle 3.) Inhibitory interneuron inhibits the alpha motor neuron of the antagonist muscle 4.) The stretched muscle contracts and the antagonist muscle relaxes

Question 36

Withdrawl reflex (somatic)

Answer 36

Pull away from painful stimuli

Question 37

Crossed extensor reflex (somatic)

Answer 37

One side reflexes and the other side extends

Question 38

Golgi tendon organ reflex (somatic)

Answer 38

Acs to inhibit a muscle from pulling too hard on a tendon

Question 39

Superficial spinal reflexes (somatic)

Answer 39

Elicited by gentle cutaneous stimulation

Question 40

Digestive system reflex (autonomic)

Answer 40

stretch the stomach, causes the colon to move

Question 41

Cardiovascular system reflex (autonomic)

Answer 41

hr, bp, vessel flow

Question 42

Integument system reflex (autonomic)

Answer 42

sweat, goosebumps

Question 43

Eyes reflex (autonomic)

Answer 43

the pupil moves in response to light

Question 44

Urinary system reflex (autonomic)

Answer 44

bladder contracts

Question 45

Reproductive system reflex (autonomic)

Answer 45

child birth, orgasm

Question 46

Why test reflexes?

Answer 46

1.) function of nerves, sensory and motor 2.) function of CNS at various levels 3.) degree of stimulation/inhibition of motor areas from the brain

Question 47

What does the muscle spindle respond to

Answer 47

length

Question 48

What does the tension organ respond to

Answer 48

tension