When the muscle is stretched it stretches the intrafusal fibers within the

When the muscle is stretched it stretches the

This preview shows page 19 - 22 out of 22 pages.

When the muscle is stretched, it stretches the intrafusal fibers within the muscle spindle a. When the intrafusal fibers are stretched, the firing rate in the afferent sensory nerve fibers is increased 2. The afferent sensory neuron synapses with alpha motor neurons, causing a contraction of the muscle 3. This reflex serves as a negative feedback mechanism to sense and resist changes in muscle length when an additional load is applied 4. Examples of stretch reflexes a. Patellar tendon (knee jerk) reflex: the patellar tendon connects the quadriceps femoris to the tibia 19
Image of page 19
1.Gamma motor neurons will stimulate the contraction of intrafusal fibers at the same time that alpha motor neurons stimulate the contraction of extrafusual fibers 20
Image of page 20
21
Image of page 21
22
Image of page 22

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture