Author Question: As Jim lifts his arms upward, Sally suddenly grabs them and pushes them down. When Jim's arms meet ... (Read 112 times)

kwoodring · **on:** Jun 22, 2018

As Jim lifts his arms upward, Sally suddenly grabs them and pushes them down. When Jim's arms meet this resistance:

a. the intrafusal muscle fibers shorten more than the extrafusal muscle fibers.
b. the contraction is lessened.
c. the extrafusal muscle fibers shorten more than the extrafusal muscle fibers.
d. the monosynaptic stretch reflex is inhibited.

Question 2

The vestibulospinal tract, the tectospinal tract, the reticulospinal tract, and the ventral corticospinal tract make up the ______________ of descending tracts from the primary motor cortex.

a. lateral group
b. ventromedial group
c. posteromedial group
d. rostral group