Physio Ch 13 Vocab. Control of Body Movement:

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Physio Ch 13 Vocab. Control of Body Movement:
2014-03-22 04:02:52
Human Physiology Silverthrone Dorner
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  1. somatic reflexes
    Reflexes that involve somatic motor neurons and skeletal muscles
  2. autonomic reflexes
    • Reflexes whose responses are controlled by autonomic neurons
    • all ___ ___ are polysynaptic, with at least one synapse in the brain and another in the autonomic ganglion
  3. Spinal reflexes
    integrated in the spinal cord
  4. cranial reflexes
    integrated in the brain
  5. innate
    • born with them, genetically determined 
    •  like the knee jerk
  6. conditioned/learned reflexes
    Pavlov's dogs salivating upon hearing a bell
  7. monosynaptic reflex
    • simplest of reflexes
    • single synapse between the afferent and the efferent neuron
  8. polysynaptic reflex
    have two or more synapses
  9. proprioceptors/sensory receptors
    • located in skeletal muscles, joint capsules, and ligaments
    • sense the body's position in space
  10. alpha motor neurons
    • the somatic motor neuron that innervate skeletal contractile fibers
    • ___ ___ ___ innervates extrafusal muscle fibers
  11. extrafusal muscle fibers
    • the effectors are contractile muscle fibers also known as ___ ___ ___
    • action potentials alpha motor neurons cause ___ ___ ___ to contract
  12. muscle spindles
    stretch receptors that send information to the spinal cord that brain about muscle length and changes in muscle length
  13. intrafusal fibers
    -each muscle spindle consists of a connective tissue capsule that encloses a group of small muscle fibers 

    -modified so that the ends are contractile but the center region lack myofibrils
  14. gamma motor neurons
    • contractile ends of the intrafusal fibers have their own innervation from ___ ___ ___
    • the non contractile central region of each intrafusal fiber is wrapped by sensory ending that are stimulated by stretch
    • synapses directly to alpha motor neurons
  15. muscle tone
    because of tonic activity, even a mucsle at rest maintains a certain level of tension
  16. stretch reflex
    the reflex pathway in which muscle stretch initiates a contraction response
  17. Golgi tendon organ
    • second type of proprioceptor
    • found at the junction of muscle fibers and tendons.
    • respond to tension created during isometric contraction
    • ___ ___ ___ reflexes cause relaxation, opposite of the reflex contraction by muscle spindle
  18. myotatic unit
    • collection of pathways controlling a single joint
    • simplest ___ ___ is a monosynaptic stretch reflex like the knee jerk
  19. reciprocal inhibition
    For a muscle to extend the leg, the antagonistic flexor muscles must relax
  20. crossed extensor reflex
    • flexion reflexes, particularly the legs, are usually accompanied by ___ ___ ___
    • -is a postural reflex that helps maintain balance when one  foot is lifted off the ground.
  21. reflex movements
    • 1 of 3 classifications of movement
    • least complex 
    • integrated primarily in the spinal cord
  22. postural reflexes
    • help maintain body position ass we stand or move through space
    • integrated in the brain
    • require continuous sensory input from visual and vestibular
  23. voluntary movements
    • 1 of 3 classifications of movement
    • most complex
    • requie integration at the cerebral cortex
    • can be initiated at will without external stimuli
  24. rhythmic movements
    central pattern generators (CPGs)
    • 1 of 3 classifications of movement
    • walking or running are a combination of rhythmic and voluntary movement.
    • once activated, networks of CNS interneurons called ___ ___ ___ maintain the spontaneous repetitive activity
  25. feedforward  reflexes
    allow the body to prepare for a voluntary movement, and feedback mechanisms are used to create a smooth, continuous motion
  26. flexion reflexes
    • polysynaptic reflex pathways that cause an arm or leg to be pulled away from a noxious stimulus, such as a pinprick or hot stove.
    • rely on divergent pathways in the spinal cord
  27. corticospinal tract
    a group of interneurons controlling voluntary movement that run from the motor cortex to the spinal cord, where they synapses directly onto somatic motor neurons