Spinal Reflexes

Question 0

What are the two types of muscle fibers?

Answer 0

Intrafusal and extrafusal

Question 1

If you increase the length of a muscle you cause it to contract via negative feedback that maintains muscle length describes what?

Answer 1

Tendon stretch myotatic

Question 2

Intrafusal fibers contain what type of motor neuron?

Answer 2

Gamma motor neuron

Question 3

Extrafusal fibers contain what type of motor neurons?

Answer 3

Alpha motor neurons

Question 4

What are the two types of extrafusal muscle fibers?

Answer 4

Type I and type II

Question 5

Slow twitch aerobic fibers describe what kind of fibers?

Answer 5

Type I

Question 6

Fast twitch anaerobic fibers describe what kind of fibers?

Answer 6

Type II

Question 7

All neurons that innervate a muscle (including alpha and gamma motor neurons) describe what?

Answer 7

Motor neuron pool

Question 8

All muscle fibers that are innervated by an alpha motor unit describe what?

Answer 8

Motor unit

Question 9

Small neurons have a lower threshold for synaptic inputs describes what?

Answer 9

Size principle

Question 10

What are the smallest motor neurons, first ones recruited, innervate intrafusal muscle fibers which produce negligible force, don’t fatigue?

Answer 10

Gamma motor neurons

Question 11

What neurons innervate type I muscle fibers, produce small force, don’t fatigue?

Answer 11

Small alpha motor neuron

Question 12

What neuron innervates type II muscle fibers, produce large force, fatigue rapidly?

Answer 12

Large alpha motor neuron

Question 13

What give information about the position of the body in space?

Answer 13

Propioceptors

Question 14

What measure muscle length and the velocity of shortening?

Answer 14

Muscle spindles

Question 15

What measures muscle force?

Answer 15

Golgi tendon organs

Question 16

What measures the angles of joints?

Answer 16

Joint angle receptors

Question 17

What type of muscle fibers have muscle spindles w/ cell bodies in the dorsal root ganglia that synapse in the spinal cord?

Answer 17

Intrafusal muscle fibers

Question 18

What are the two types of intrafusal muscle fibers?

Answer 18

Static and dynamic

Question 19

What are the two types of muscle spindle receptors?

Answer 19

Primary and secondary

Question 20

What type of spindle receptors are wrapped around static and dynamic intrafusal muscle fibers, type Ia fibers?

Answer 20

Primary spindle receptors

Question 21

What type of spindle receptors wrap around only static intrafusal muscle fibers, type II fibers?

Answer 21

Secondary spindle receptors

Question 22

What type of muscle fiber gives information about velocity and length?

Answer 22

Type Ia

Question 23

What type of muscle fiber gives information about length only?

Answer 23

Type II

Question 24

What controls the sensitivity of spindle receptors?

Answer 24

Gamma motor neurons

Question 25

What modulate the stretch reflex but are not directly apart of it, exist in the tendon of the muscle, are situated in a good position to measure force, and are sensitive to active contraction?

Answer 25

Golgi tendon organs

Question 26

What are primarily involved in the stretch reflex?

Answer 26

Muscle spindles

Question 27

An increase in muscle length leads to an increase in muscle firing leads to an increase in activity of the alpha motor neuron which leads to contraction describes what?

Answer 27

Homonymous stretch reflex

Question 28

In the homonymous stretch reflex afferents control what?

Answer 28

Spindle fibers

Question 29

In the homonymous stretch reflex efferents control what?

Answer 29

Alpha motor neurons

Question 30

What is important for muscle tone and can induce spasticity?

Answer 30

Homonymous stretch reflex

Question 31

Low threshold gamma interneurons fire, activation of intrafusal muscle fibers which stretch muscle spindle, increase activity of spindle fibers, combination of spindle afferents with w/ descending alpha neuron afferents bring neuron to threshold, contraction of extrafusal muscle fibers describes what?

Answer 31

Alpha gamma co activation -voluntary movement

Question 32

What type of muscles increase the activity of the stretch reflex on each other?

Answer 32

Synergists

Question 33

What type of muscles decrease the activity of the stretch reflex on each other?

Answer 33

Antagonistic muscles

Question 34

Interneuron GABA release that activates GABAb receptor which blocks calcium channel in presynaptic junction describes what?

Answer 34

Antagonistic muscle decreased reflex

Question 35

What GABAb agonist decrease stretch reflexes and motor spasticity?

Answer 35

Baclofen