Motor 3/4

Question 1

anticipatory motor control, locomotor initiation

Answer 1

Reticulospinal tract:

Question 2

unconscious responses to vestibular stimulation

Answer 2

Vestibulospinal tract:

Question 3

(aka “tectospinal”) : orientation of gaze and stance to a stimulus in space

Answer 3

Colliculospinal tract

Question 4

Superior Colliculus aka

Answer 4

Tecum

Important for orienting movements toward unexpected stimulus

Important in Gaze

Question 5

Superior colliculus maps:

Answer 5

diverse sensory modalities onto external space

Question 6

Axons of M1 pyramidal neurons descend in the:

Answer 6

corticobulbar and corticospinal tracts.

M1 is brodman area 4

Question 7

lateral corticospinal tract –> 90% of fibers cross the mideline at the caudal end of the __________

Answer 7

medulla

Question 8

10% “lateral corticospinal tract” do not cross at medulla. These become the ventral (aka medial) cs tract and serve:

Answer 8

axial musculature like the RF.

Some fibers contact motor neurons of the hand directly, but very few.

Question 9

Net population vectors

Answer 9

M1 Averages of Tuning Curves EXACTLY encodes movement direction

Encodes critical aspects of voluntary movements

Question 10

Upper motor neuron syndrome

Answer 10

Short term: flaccidity of body and lower face contralateral to damage

Limbs are most affected due to spared brainstem control areas

After spinal shock wears off:

Babinski sign: extension of big toe and fanning of other toes when stroking sole of foot

Spasticity: hyperactive stretch reflexes, clonus (oscillatory response to muscle stretching)

Rigidity of extensor muscles of legs and flexor muscles of arms due to reduced inhibitory tone

Loss of ability to perform fine movements.