Deck 29: Balance and Control of Movement

Question 1

The substantia nigra

A) Excites the direct pathway and inhibits the indirect pathway
B) Inhibits the direct pathway and excites the indirect pathway
C) Uses serotonin as its main neurotransmitter
D) Connects mainly to the caudate and the external globus pallidus
E) Both A and C are correct

Answer 1

A

Question 2

Motor neurons for the proximal m uscles are located

A) M edially in th e ve ntral h orn
B) Laterally in the ventral horn
C) Tow ards the outside of the cord
D) Tow ards the inside of the cord
E) N ea r th e m us cle

Answer 2

A

Question 3

Apraxia, the lack of coordination of bilateral movem ents, can be produced by deficits in the

A) Substan tia nigra
B) Primary motor cortex
C) Supplementary motor cortex
D) Sensory association cortex
E) Prefrontal cortex

Answer 3

C

Question 4

The substantia nigra

A) uses dopamine as a neurotransmitter
B) activates the direct pathway to promote movem ent
C) inhibits the indirect pathway that inhibits movement
D) is dysfunctional in Parkinson's disease
E) All of the above are true

Question 5

Myotom es are

A) Groups of muscles whose alpha motor neurons lie usually in a single spinal segment
B) Large muscles
C) Region of the sk eleton that map s onto a region of the spinal cord
D) Region of the skin whose sensory information enters the spinal cord at one segment
E) Grou p of m otor neurons w ithin the spinal cord

Question 6

"Duplicate" motor comm ands enter the cerebellum over

A) Pu rk inje ce lls
B) Ba sk et c ells
C) Climbing fibers
D) M oss y fibers
E) Rubrospinal tract

Question 7

The m otor neuron pool for a given muscle is the

A) Extracellular fluid that bathes the motor neurons
B) Cerebrospinal fluid, CSF
C) Set of motor neurons grouped vertica lly in th e sp inal c ord tha n in ne rva te a s ing le m us cle
D) Se t of m oto r ne ur on s in the prim ar y co rte x th at in ne rva tes a s ing le m us cle
E) Motor neurons not yet recruited

Question 8

The primary motor cortex is located in the

A) Pre-central gyrus
B) Post-central gyrus
C) Dorsal columns
D) Dorsal root
E) Ventral horn of the spinal cord

Question 9

Rotation of the head in the horizontal plane excites

A) ha ir ce lls in the utr icle
B) hair cells in the posterior canal
C) hair cells in the antrerior canal
D) hair cells in the horizontal canal
E) ha ir ce lls in the sa cc ule

Question 10

Rotation of the head to its right

A) Excites h air cells in the right horizon tal canal bu t inhibits them in the left
B) Ex cite s h air ce lls in bo th r igh t an d le ft h or izon tal c an als
C) Inh ibits ha ir ce lls in bo th r igh t an d le ft h or izon tal c an als
D) Inhibits hair cells in the right horizontal canal but excites them in the left
E) Ma ke s a p ers on d izzy

Question 11

Sensory information about what movem ent has occurred enters the cerebellum over

A) Pu rk inje ce lls
B) Ba sk et c ells
C) Clim bing fibers
D) Mos sy fibers
E) Rubrospinal tract

Question 12

"L ow er m oto r ne ur on s" are ne ur on s w ho se ce ll bo die s a re loc ate d in

A) Pre-central gyrus
B) Post-central gyrus
C) Dorsal columns
D) Dorsal root
E) Ven tral ho rn of th e sp inal co rd

Question 13

D ef or m atio n o f th e k ino ciliu m aw ay fr om the oth er ste re oc ilia

A) Opens a Ca₂+ ch an ne l tha t de po lar izes the ha ir ce lls
B) Opens a Na+ ch an ne l tha t de po lar izes the ha ir ce lls
C) Opens a C l- ch an ne l tha t hyp er po lar izes the ha ir ce lls
D) Opens a C l- ch an ne l tha t de po lar izes the ha ir ce lls
E) Opens a K+ channel that depolarizes the cells because the endolymph has a very high [K +]

Question 14

Muscles can vary their force mainly by which of the following ?

A) Recruiting mo re motor units
B) Increasing the len gth of t he m us cle
C) Increasing the frequ ency o f stimulation of recruited m otor un its
D) Increasing the phosphorylation of myosin light chains
E) A and C are correct

Question 15

The "po pula tion co de" f or m usc le forc e ref ers to

A) W hether slow twitch or fast twitch muscles are recruited
B) The number of motor units, and therefore muscle fibers, that are active
C) W hich muscles are activated
D) Inverse innervation of antagonistic muscles
E) Co-innervation of synergistic muscles

Question 16

Which of the following is not part of the basal ganglia?

A) External globus pallidus
B) Caudate nucleus
C) Putamen
D) Superior colliculus
E) Substan tia nigra

Question 17

Sensory information about static gravity derives from hair cells in the

A) Horizontal canal
B) Anterior canal
C) Posterior canal
D) Sa ccu le an d U tricle
E) Cochlea