Y2 M2

Question 1

Extrafusal fibers are innervated by

a. alpha motor nerves
b. beta motor nerves
c. delta motor nerves
d. gamma gain

Answer 1

a. alpha motor nerves

Question 2

Activation of efferent alpha nerve fibers produces _________ of extrafusal fibers of the main muscle mass.

a. stretch
b. contraction
c. shear
d. torsion

Answer 2

b. contraction

Question 3

Activation of efferent gamma nerve fibers contract the ______________ muscle fibers of the muscle spindles.

a. large extrafusal
b. small extrafusal
c. large intrafusal
d. small intrafusal

Answer 3

d. small intrafusal

Question 4

The Ia afferent to the efferent alpha nerve reflex is _________.

a. monosynaptic
b. polysynaptic

Answer 4

a. monosynaptic

Question 5

______ transmit information to the CNS regarding the length or tension of muscles.

Answer 5

proprioceptors

Question 6

T/F
GTO’s respond to changes in force and not changes in length.

Answer 6

True

Question 7

The muscle spindle and its intrafusal muscle fibers are innervated by _________.

a. alpha motor nerve
b. beta motor nerve
c. delta motor nerve
d. gamma motor nerve

Answer 7

d. gamma motor nerve

Question 8

There are two types of proprioceptive structures within each muscle spindle:

a. GTO and annulospiral
b. GTO and flower-spray
c. annulospiral and flower-spray

Answer 8

c. annulospiral and flower-spray

Question 9

T/F
Group 1a are myelinated afferent fibers that report proprioceptive information to the spinal cord from the annulospiral endings, while group 2 are unmyelinated fibers that report to proprioceptive information from the flower-spray endings.

Answer 9

True

Question 10

T/F
Gamma motor nerves “set” the length of the intrafusal muscle fibers.

Answer 10

True

Question 11

Mechanically, the T11/12 (PPP) harnesses the primary motion of the upper polygon, which is ________ and in the lower polygon is ________.

a. SB/R and F/E
b. F/E SB/R
c. SB/R, torsion

Answer 11

a. SB/R and F/E