Describe The Sequence Of Events That Occurs From The Time The Patellar Tendon

The Parkinson's-Reversing Breakthrough

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■ Figure 12.30 The crossed-extensor reflex. This complex reflex demonstrates double reciprocal innervation.

Table 12.8 Symptoms of Upper Motor Neuron Damage

Babinski's reflex—Extension of the great toe when the sole of the foot is stroked along the lateral border Spastic paralysis—High muscle tone and hyperactive stretch reflexes;

flexion of arms and extension of legs Hemiplegia—Paralysis of upper and lower limbs on one side—commonly produced by damage to motor tracts as they pass through internal capsule (such as by cerebrovascular accident—stroke) Paraplegia—Paralysis of the lower limbs on both sides as a result of lower spinal cord damage

Quadriplegia—Paralysis of upper and lower limbs on both sides as a result of damage to the upper region of the spinal cord or brain Chorea—Random uncontrolled contractions of different muscle groups (as in Saint Vitus' dance) as a result of damage to basal nuclei Resting tremor—Shaking of limbs at rest; disappears during voluntary movements; produced by damage to basal nuclei Intention tremor—Oscillations of the arm following voluntary reaching movements; produced by damage to cerebellum

Test Yourself Before You Continue

1. Draw a muscle spindle surrounded by a few extrafusal fibers. Indicate the location of primary and secondary sensory endings and explain how these endings respond to muscle stretch.

2. Describe all of the events that occur from the time the patellar tendon is struck with a mallet to the time the leg kicks.

3. Explain how a Golgi tendon organ is stimulated and describe the disynaptic reflex that occurs.

4. Explain the significance of reciprocal innervation and double reciprocal innervation in muscle reflexes.

5. Describe the functions of gamma motoneurons and explain why they are stimulated at the same time as alpha motoneurons during voluntary muscle contractions.

6. Explain how a person with spinal cord damage might develop clonus.

PtW Parkinson's disease (or paralysis agitans) is a disorder of the basal nuclei involving degeneration of fibers

__Ji i~{ from the substantia nigra. These fibers, which use dopamine as a neurotransmitter, are required to antagonize the effects of other fibers that use acetylcholine (ACh) as a transmitter. The relative deficiency of dopamine compared to ACh is believed to produce the symptoms of Parkinson's disease, including resting tremor. This "shaking" of the limbs tends to disappear during voluntary movements and then reappear when the limb is again at rest.

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Essentials of Human Physiology

Essentials of Human Physiology

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Responses

  • bruno
    What sequence occur when the patellar tendon is streched?
    7 years ago

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