$$\text{Impulse Rate} \propto \text{Degree of Stretch}$$

Question 1

Which of the following best describes the role of the integration center in a reflex arc?

Accepted Answer

It is a region within the CNS where sensory input is processed, and motor output is generated, either monosynaptically or polysynaptically.

Question 2

A patient presents with an absent patellar reflex. Which of the following could be a possible cause?

Accepted Answer

Peripheral nerve damage or ventral horn injury affecting the reflex arc.

Question 3

Which of the following is TRUE regarding the stretch reflex?

Accepted Answer

It is a monosynaptic and ipsilateral reflex that causes contraction of the stretched muscle.

Question 4

What is the primary function of the tendon reflex?

Accepted Answer

To prevent muscle damage by causing relaxation in response to excessive tension.

Question 5

Which of the following correctly matches the type of reflex with its effector?

Accepted Answer

Somatic reflex – skeletal muscle

Question 6

During the patellar (knee-jerk) reflex, which process ensures that the antagonistic muscle relaxes while the quadriceps contracts?

Accepted Answer

Reciprocal inhibition

Question 7

Which of the following best explains why infants exhibit Babinski’s sign?

Accepted Answer

Their nervous systems are not completely myelinated.

Question 8

A gymnast on a balance beam requires rapid adjustment of muscle spindle sensitivity. Which neurons are primarily responsible for this adjustment?

Accepted Answer

Gamma (\gamma) motor neurons

Question 9

Which of the following is a learned (acquired) reflex?

Accepted Answer

Driving skills

Question 10

Which of the following is TRUE about the flexor (withdrawal) reflex?

Accepted Answer

It is polysynaptic and ipsilateral.

Question 11

What is the correct sequence of components in a reflex arc?

Accepted Answer

Receptor → Sensory neuron → Integration center → Motor neuron → Effector

Question 12

Which of the following proprioceptors provides information about muscle length?

Accepted Answer

Muscle spindles

Question 13

Which afferent ending in the muscle spindle is stimulated by both the rate and degree of stretch?

Accepted Answer

Anulospiral endings

Question 14

A patient steps barefoot on broken glass. Which reflexes are involved in the immediate response?

Accepted Answer

Flexor (withdrawal) reflex and crossed-extensor reflex

Question 15

Which equation best represents the relationship between the rate of muscle spindle impulses and muscle stretch?

Accepted Answer

$$	ext{Impulse Rate} \propto 	ext{Degree of Stretch}$$

Question 16

Which of the following is a clinical implication of an exaggerated stretch reflex?

Accepted Answer

May indicate degeneration or pathology of specific nervous system regions.

Question 17

Which of the following is TRUE about superficial reflexes?

Accepted Answer

They signal problems in upper motor pathways or cord-level reflex arcs.

Question 18

Which spinal cord segments are tested by the plantar reflex?

Accepted Answer

L4 to S2

Question 19

Which of the following best describes reciprocal activation in the tendon reflex?

Accepted Answer

Contracting muscle relaxes while antagonist contracts.

Question 20

Which of the following is the correct response to stroking the lateral aspect of the sole of the foot in a healthy adult?

Accepted Answer

Downward flexion of the toes.

Reflex Arcs and Somatic Spinal Reflexes: Structure and Function

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