Motor Systems

Question 1

Most important role of gamma motoneurons

Answer 1

Maintain 1a afferent activity during muscle contraction

Question 2

Stretch reflex (myotatic reflex or knee jerk reflex)

Answer 2

MONOsynaptic
Ia
muscle is stretched –> contraction of muscle

Question 3

Clasp-Knife reflex (Golgi Tendon Reflex or Inverse Stretch Reflex)

Answer 3

DIsynaptic
Ib
muscle contracts –> relaxation of muscle

Question 4

Flexor Withdrawal Reflex

Answer 4

POLYsynaptic
II, III, IV
pain –> ipsilateral flexion; contralateral extension

Question 5

Detect DYNAMIC changes

Answer 5

Nuclear Bag Fibers

Ia

Question 6

Detect STATIC changes

Answer 6

Nuclear Chain Fibers

II

Question 7

Muscle stretch leads to a direct increase firing rate of which type of nerve

Answer 7

Group Ia fibers

Question 8

Muscle that contracts during knee-jerk reflex/patellar reflex

Answer 8

Quadriceps femoris (extensor muscle)

Question 9

Reflex responsible for monosynaptic excitation of ipsilateral homonymous muscle

Answer 9

Stretch reflex (myotatic reflex or knee jerk reflex)

Question 10

Reflex responsible for polysynaptic excitation of contralateral extensors

Answer 10

Flexor Withdrawal Reflex

Question 11

Claw hand

Answer 11

Ulnar nerve

Question 12

Hand of Benediction or Ape Hand

Answer 12

Median nerve

Question 13

Wrist drop

Answer 13

Radial nerve

Question 14

Essential for voluntary movement

Answer 14

precentral gyrus
corticospinal tract
corticobulbar tract