Motor systems Flashcards Preview

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Flashcards in Motor systems Deck (37)
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1
Q

Alpha motoneuron

A

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

2
Q

gamma motoneuron

A

class of motoneuron that only innervates intrafusal fibers

3
Q

motor unit

A

a single alpha motoneuron and all the muscle fibers it innervates

4
Q

muscle spindle

A

composed of intrafusal fibers that measure the length of the muscle

5
Q

golgi tendon organ

A

detect muscle tension, innervated by 1b afferents

6
Q

myotatic reflex

A

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

7
Q

flexor reflex

A

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

8
Q

crossed extensor reflex

A

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

9
Q

corticobulbar projections

A

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

10
Q

corticopontine projections

A

terminate in pontine nuclei, influence cerebellum

11
Q

red nucleus

A

source of the rubrospinal tract

12
Q

ventromedial tracts

A

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

13
Q

_________tract stimulates flexors, inhibits extensors

A

reticulospinal

14
Q

________tract stimulates extensors, inhibits flexors

A

vestibulospinal

15
Q

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

A

tectospinal

16
Q

dorsolateral tracts

A

control distal muscles of the limb, voluntary movements

17
Q

_________tract affects forelimb muscles

A

rubrospinal

18
Q

_________tract affects distal muscles of both limbs

A

corticospinal

19
Q

motor component of the corticospinal tract

A

primary motor cortex (MI) in the brain

20
Q

non-motor component of the corticospinal tract

A

somatic sensory cortex (SI) in the brain

21
Q

central pattern generators

A

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

22
Q

sensory-motor basal ganglia loop

A

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

23
Q

limbic basal ganglia loop

A

limbic cortex>ventral striatum>ventral pallidum>mediodorsal thalamus

24
Q

cerebrocerebellum input

A

pontine nuclei

25
Q

cerebrocerebellum output

A

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

26
Q

cerebrocerebellum fxn

A

planning movements and fine motor control

27
Q

spinocerebellum input

A

spinal cord, vestibular n, trigeminal n.

28
Q

IT’S THE MOST WONDERFUL TIME

A

OF THE YEARRRRRRR!!!!!!!!

29
Q

spinocerebellum output

A

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

30
Q

spinocerebellum fxn

A
  • vermis: posture and locomotion

- medial hemisphere: motor coordination of extremities

31
Q

vestibulocerebellum input

A

vestibular nerve and nuclei

32
Q

vestibulocerebellum output

A

vestibular nuclei

33
Q

vestibulocerebellum fxn

A

equilibrium, coordination of head and eye movements

34
Q

rostral cerebellar peduncle:

A

output to red nucleus and VL thalamus

35
Q

middle cerebellar peduncle:

A

input from pons

36
Q

caudal cerebellar peduncle

A

input from vestibular nuclei and spinal cord

37
Q

deep cerebellar nuclei

A

generate outputs from the cerebellum to other brain regions