Spinal Reflexes and EMG Demonstration

Question 1

direct synaptic contacts are?

Answer 1

monosynaptic

Question 2

indirect synaptic contact are?

Answer 2

polysynaptic

Question 3

Only afferent in CNS that receives a nerve supply?

Answer 3

Muscle spindle-stretch receptor

Question 4

Muscle spindle is arranged in?

Answer 4

parallel with extrafusal (regular) muscle fibers

Question 5

Intrafusal muscle fiber are innervated by?

Answer 5

target for gamma motor neurons, smaller soma than alpha motor neuron

Question 6

What are the two sensory zones for intrafusal fibers?

Answer 6

1. Central region (bag) = 1a receptors=dynamic

2. distal region= type II receptors = static

Question 7

Process in which agonist excited, antagonists inhibited by gamma 1a inhib. interneuron is called

Answer 7

reciprocal inhibition

Question 8

What occurs during the stretch reflex?

Answer 8

When alpha motor neuron extrafusal Muscle fibers contract -> intrafusal muscle fibers gamma motor neurons also shorten to remain sensitive to further changes n muscle length

Question 9

What makes GTO fire?

Answer 9

GTO fires with active muscle contractions-not with passive stretch

Question 10

Describe a GTO receptor and its role.

Answer 10

type Ib gamma arranged in series with extrafusal fibers.

GTO muscle reflex for active contraction: fires Ib inhib. interneuron for agonist + excites antagonist muscle

Question 11

What is CPG

Answer 11

neuron in the spinal cord that can produce coordinated movement in the absence of higher inputs