Motor Systems

Question 1

Alpha motor neurons

Answer 1

Large cell body in Ventral horn. Final common path by which brain and SC influence motor output

Question 2

Motor units

Answer 2

Single Alpha motor neuron and all muscle fibers it innervates

Question 3

Gamma motor neurons

Answer 3

Innervate intrafusal muscle fibers

Question 4

Muscle Spindle

Answer 4

In intrafusal muscle, in parallel w extrafusal muscle. Innervated by 1a afferents which convey status of muscles to CNS

Question 5

Golgi Tendon Organs

Answer 5

Detect muscle tension at musculotendon jct in series w muscle. innervated by 1b afferents.

Question 6

Myotatic reflex

Answer 6

Stretch muscle spindles, activate 1a afferents, MONOSYNAPTIC muscular contraction to protect muscles from over stretching

Question 7

Flexor reflex

Answer 7

Extensors inhibited when flexors are excited

Question 8

Crossed extension Reflex

Answer 8

Posture maintained by exciting extensors on side opposite flexor excitation

Question 9

Central Pattern Generator

Answer 9

Opperate at local spinal level and gen basic rhythmic motor output through communicating amoung spinal segments

Question 10

Ventromedial tracts

Answer 10

Maintain posture. Lateral Vestibulospinal, Reticulospinal, Tectospinal tracts

Question 11

Dorsolateral Tracts

Answer 11

Distal muscles of limbs, Voluntary movement. Rubrospinal, Corticospinal Tracts

Question 12

Lateral Vestibulospinal Tract

Answer 12

Stimulate extensors, inhibit flexors

Question 13

Reticulospinal tract

Answer 13

Stimulate flexors, inhibit extensors

Question 14

Tectospinal Tract

Answer 14

Muscles of neck and upper trunk, orienting responses

Question 15

Rubrospinal tract

Answer 15

Affects forelimb muscles

Question 16

Corticospinal tract

Answer 16

affects hindlimb muscles

Question 17

basal Ganglia

Answer 17

Continually updates which cortical activity is important. then gates thalamus accordingly (initiating movements)
Caudate, Putamen, Globus pallidus

Question 18

Cerebellum

Answer 18

Provides for precise timing of movements w contiual direct sensory feedback (fine movements)

Question 19

Dorsum striatum

Answer 19

Caudate and Putamen

Question 20

Ventral Striatum

Answer 20

nucleus accumbens and olfactory tubercle

Question 21

Cerebrocerebellum

Answer 21

Lat Hemispheres. Planning movements and fine motor control

Question 22

Spinocerebellum

Answer 22

Vermis and Medial hemisphere. Posture/Locomotion and Coordination of extremities

Question 23

Vestibulocerebellum

Answer 23

Nodulus and flocculi. Equilibrium, coordinate head and eye movements via MLF