Motor systems

Question 1

Alpha motoneuron

Answer 1

contact muscle fibers, final pathway brain uses to control motor output

Question 2

gamma motoneuron

Answer 2

class of motoneuron that only innervates intrafusal fibers

Question 3

motor unit

Answer 3

a single alpha motoneuron and all the muscle fibers it innervates

Question 4

muscle spindle

Answer 4

composed of intrafusal fibers that measure the length of the muscle

Question 5

golgi tendon organ

Answer 5

detect muscle tension, innervated by 1b afferents

Question 6

myotatic reflex

Answer 6

stretch reflex, group 1a fibers travel up dorsal horn, contact interneurons in intermediate zone, and then contact the alpha motoneuron in the ventral horn to innervate the same muscle that the signal came from, a monosynaptic reflex

Question 7

flexor reflex

Answer 7

flexors are excited while extensors are inhibited, example is removing hand from hot stove

Question 8

crossed extensor reflex

Answer 8

extensors are excited on the opposite side of the body that has excited flexors, example is stepping on a nail

Question 9

corticobulbar projections

Answer 9

terminate in the brainstem, influence cranial nerve motor nuclei via pontine and medullary reticular formations

Question 10

corticopontine projections

Answer 10

terminate in pontine nuclei, influence cerebellum

Question 11

red nucleus

Answer 11

source of the rubrospinal tract

Question 12

ventromedial tracts

Answer 12

maintain posture by controlling axial skelelton, limb girdles, and proximal limb

Question 13

_________tract stimulates flexors, inhibits extensors

Answer 13

reticulospinal

Question 14

________tract stimulates extensors, inhibits flexors

Answer 14

vestibulospinal

Question 15

_________ tract is involved with muscles of the neck and upper trunk; orienting responses

Answer 15

tectospinal

Question 16

dorsolateral tracts

Answer 16

control distal muscles of the limb, voluntary movements

Question 17

_________tract affects forelimb muscles

Answer 17

rubrospinal

Question 18

_________tract affects distal muscles of both limbs

Answer 18

corticospinal

Question 19

motor component of the corticospinal tract

Answer 19

primary motor cortex (MI) in the brain

Question 20

non-motor component of the corticospinal tract

Answer 20

somatic sensory cortex (SI) in the brain

Question 21

central pattern generators

Answer 21

operate at the local spinal level and generate a basic rhythmic motor output, modulated by tectospinal, rubrospinal, and corticospinal tracts, interconnected CPGs provide the basic rhythm of locomotion

Question 22

sensory-motor basal ganglia loop

Answer 22

sensory-motor and premotor cortex>putamen>global pallidus and substantia nigra>pars reticulata>ventrolateral thalamus

Question 23

limbic basal ganglia loop

Answer 23

limbic cortex>ventral striatum>ventral pallidum>mediodorsal thalamus

Question 24

cerebrocerebellum input

Answer 24

pontine nuclei

Question 25

cerebrocerebellum output

Answer 25

dentate nucleus, then red nucleus, motor thalamus, motor and premotor cortex

Question 26

cerebrocerebellum fxn

Answer 26

planning movements and fine motor control

Question 27

spinocerebellum input

Answer 27

spinal cord, vestibular n, trigeminal n.

Question 28

IT’S THE MOST WONDERFUL TIME

Answer 28

OF THE YEARRRRRRR!!!!!!!!

Question 29

spinocerebellum output

Answer 29

fastigial, globose, emboliform nuclei, then to brainstem motor centers

Question 30

spinocerebellum fxn

Answer 30

• vermis: posture and locomotion

- medial hemisphere: motor coordination of extremities

Question 31

vestibulocerebellum input

Answer 31

vestibular nerve and nuclei

Question 32

vestibulocerebellum output

Answer 32

vestibular nuclei

Question 33

vestibulocerebellum fxn

Answer 33

equilibrium, coordination of head and eye movements

Question 34

rostral cerebellar peduncle:

Answer 34

output to red nucleus and VL thalamus

Question 35

middle cerebellar peduncle:

Answer 35

input from pons

Question 36

caudal cerebellar peduncle

Answer 36

input from vestibular nuclei and spinal cord

Question 37

deep cerebellar nuclei

Answer 37

generate outputs from the cerebellum to other brain regions