College of Massage Therapists of British Columbia (CMTBC) Practice Exam

What action does the flexor withdrawal reflex perform?

1. Withdraws from a painful stimulus

2. Contracts muscle for strength

3. Supports limbs during stretching

4. Protects joints from injury

The correct answer is: Withdraws from a painful stimulus

The flexor withdrawal reflex is a protective reflex that occurs involuntarily in response to a painful stimulus. When a painful stimulus is applied to a specific area of the skin, sensory neurons signal the spinal cord, which then orchestrates an immediate response to withdraw the affected limb. This reflex is crucial for an organism's ability to react quickly to harmful stimuli, reducing the risk of injury. The process involves the activation of flexor muscles while simultaneously inhibiting the extensor muscles, enabling a swift withdrawal movement away from the source of pain. This mechanism highlights the body's innate ability to protect itself, making it a vital aspect of survival. In contrast, the other options relate to different reflex actions or protective mechanisms. They do not accurately describe the specific function of the flexor withdrawal reflex. For instance, contracting muscles for strength refers to voluntary muscular control often involved in activities requiring force, while supporting limbs during stretching pertains to proprioceptive reflexes that maintain posture and balance. Protecting joints from injury would involve different stabilizing reflexes rather than the immediate withdrawal response characteristic of the flexor withdrawal reflex.