motor 1
Terms
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copy deck
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T/F
motor system control skeletal muscle activity(behavior) and vegetative functions of the body through the somatic motor system and autonomic nervous system. Together these functions are known as EFFERENT activity - T
- 3 types of muscles
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striated
cardiac(heart muscle)
smooth(autonomic NS) - 3 classes of movements
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1.simple reflex(hand on hot stove)
2.coordinated more complex reflex (walking, rhythmic patterns not controlled)require more than one kind of muscle
3.Voluntary, skilled mov (driving, pitching a ball, speech) - hierarchical system
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spinal cord
brainstem
motor cortex
basal ganglia
cerebellum - cell bodies for motor neurons located in
- ventral horn, also found in brainstem regions for cranial nerves that control motor
- cranial nerves for motor
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hypoglossal(tongue)
facial muscles
trigeminal(face senses and chewing)
extra oculoary muscles -
T/F
muscles pull on a joint, they can't push - T
- Axial muscles (somatic muscles)
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movement of trunk
found throughout the length of spinal cord - Proximal muscles (somatic muscles)
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move shoulder, elbow, pelvis, knee
-critical for locomotion
neurons found in nearest cervical(arm) and lumbosacral(leg) enlargements - Distal muscles (somatic muscles)
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move hands, feet, digits for manipulation of objects
neurons found in nearest cervical(arm) and lumbosacral(leg) enlargements - Lower motor neurons
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final common pathway for movement.
-motor neurons directly inervate skeletal muscles
-found in ventral horn->ventral root->spinal nerve efferent -
Spatial distribution of lower motor neurons
medial-lateral rule
dorsal-ventral rule -
medial-lateral
axial-medial
distal-lateral
dorsal-ventral
flexor-dorsal
extensors-ventral -
T/F
Each muscle fiber is innervated by 1 axon
from motor neuron - T
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Motor unit
small
large -
alpha motor neurons and all muscle fibers it innervates
-many motor units necessary to contract entire muscle
small-smaller muscles that control mov of fingers and rotation of the eyes(3 muscles per motor neuron)
Large-more force during contraction (1000:1) - Motor neuron pool
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all alpha motor neurons that innervate one muscle
-synergistic motor units make up a motor neuron pool