Hall: Guyton and Hall Textbook of Medical Physiology, 12th Edition
Chapter 54: Motor Functions of the Spinal Cord; The Cord Reflexes
Test Bank
1. In a muscle spindle receptor, which fiber is responsible for the dynamic response?
A. The extrafusal muscle fiber
B. The static nuclear bag fiber
C. The nuclear chain fiber
D. The dynamic nuclear bag fiber
2. Type II sensory afferents from the muscle spindle receptor are attached to which of the
following structures?
A. The extrafusal muscle fiber
B. The dynamic nuclear bag fiber
C. The nuclear chain fiber
D. The gamma S fiber
3. Which of the following will increase the sensitivity of the stretch reflex?
A. Cutting the dorsal root fibers associated with the muscle in which the stretch reflex is
being examined
B. Increasing the activity of the medullary reticular nuclei
C. Bending the head forward
D. Increased activity in the fusimotor (gamma motor neuron) system
4. Activation of a type 1b sensory neuron will have which of the following effects?
A. Contraction of the muscle fiber associated with this neuron
B. An initiation of a complex spike output signal
C. Central nystagmus
D. Inhibition of muscle contraction in the muscle fiber associated with this neuron
5. Assuming all sensory, motor, and reflex neuronal pathways are intact, skeletal muscle
contraction can be caused by stimulation of which of the following?
A. Type 1a sensory nerve endings
B. Type 1b sensory nerve endings
C. Neurons in the ventromedial hypothalamus
D. Preganglionic parasympathetic vagal nerves
Test Bank
54-2
6. The dynamic response of the muscle spindle receptor can best be described as:
A. An increase in the activity of the nuclear chain fibers as a result of the change in
length of the muscle fiber
B. An increase on activity of the group II sensory afferents in response to the rate of
change in length of the muscle fiber
C. A decrease in the activity of the group 1a sensory afferents in response to a change in
length of the muscle fiber
D. An increase in the activity of the muscle spindle receptor that is proportional to the
rate of change in length of the muscle fiber
7. Stimulation of type II sensory fibers innervating a muscle spindle:
A. Will inhibit muscle contraction
B. Will activate an inhibitory interneuron in the anterior horn of the spinal cord and lead
to inhibition of Golgi tendon response
C. Will activate a gamma motor neuron connected to the muscle containing the spindle
receptor
D. Will activate an alpha motor neuron connected to the muscle containing the spindle
receptor
8. The function of the Golgi tendon organ is:
A. To sense the length of the muscle tendon in which it is located
B. To provide the cerebellum with feedback information concerning which motor
impulses have arrived at the anterior motor neurons of the spinal cord
C. To transmit muscle stretch information to higher brain centers
D. To sense muscle tension and equalize the contractile force exerted by groups of
muscle fibers in a muscle
9. Assuming all sensory, motor, and reflex pathways are intact, muscle contraction can be
caused by stimulation of which of the following types of neurons?
A. Alpha motor neurons
B. Gamma motor neurons
C. Type 1a sensory endings from a nuclear bag fiber
D. All of the above
10. Type 1a afferents innervate which of the following types of receptors in the muscle
spindle apparatus?
A. Nuclear chain fibers
B. Static nuclear bag
C. Dynamic nuclear bag fibers
D. All of the above
11. The sensitivity of the stretch reflex can be altered by:
A. The activity in the olivocerebellar tract
B. Simultaneous stimulation of the primary motor cortex and the supplemental motor
area of the cortex
C. The activity of the pontine reticular nuclei
D. The activity of the corticospinal tract
12. The stretch reflex initiated by tapping on the patellar tendon causes muscle contraction
by which of the following mechanisms?
A. Activation of type Ia sensory fibers
B. Activation of type Ib sensory fibers
C. Activation of gamma motor neurons
D. Activation of inhibitory interneurons
13. Under normal conditions, activation of which of the following can lead to muscle
contraction?
A. Free nerve endings
B. Type Ia sensory fibers
C. Nuclear chain fibers
D. All of the above