Question 22 A reflex that causes muscle relaxation and lengthening in response to muscle tension is called a flexor reflex plantar reflex Golgi tendon reflex crossed extensor reflex A Moving to another question will save this resnonra
The Correct Answer and Explanation is:
Correct Answer: Golgi tendon reflex
Explanation:
The Golgi tendon reflex, also known as the inverse myotatic reflex, is a protective reflex that causes muscle relaxation and lengthening in response to excessive tension in the muscle. This reflex is mediated by the Golgi tendon organs (GTOs)—specialized sensory receptors located within tendons, typically near the junction with muscle fibers.
How It Works:
When a muscle contracts, tension builds up in its tendons. If the tension becomes too great, the Golgi tendon organs are activated. These organs send afferent impulses to the spinal cord via Ib sensory neurons, which then synapse with inhibitory interneurons in the spinal cord. These interneurons inhibit the alpha motor neurons that cause the muscle to contract. As a result, the muscle relaxes and lengthens, thereby reducing the tension and preventing injury such as tendon tears or muscle strain.
Comparison with Other Reflexes in the Options:
- Flexor Reflex:
- Also known as the withdrawal reflex, it is a protective response to a painful stimulus.
- It causes contraction of flexor muscles and withdrawal of the limb from the source of pain.
- It involves muscle contraction, not relaxation.
- Plantar Reflex:
- Tested using the Babinski sign.
- In adults, the normal response is toe flexion when the sole is stimulated.
- It is more of a diagnostic tool for neurological function, not a reflex designed for muscle protection from tension.
- Crossed Extensor Reflex:
- Often occurs in conjunction with the flexor reflex.
- While one limb withdraws (flexes), the opposite limb extends to maintain balance.
- Like the flexor reflex, it involves muscle contraction, not relaxation.
Conclusion:
The Golgi tendon reflex is the only reflex among the options that causes muscle relaxation and lengthening in response to tension. It serves a critical protective role in preventing musculoskeletal injuries. Understanding this reflex is essential in both neurological assessments and in designing safe exercise or rehabilitation programs.