​The sensory nerve fibers (Column X) and the sensory receptors connected to different sensory nerves (Column Y) are given below.

Which of the following options represents the correct match between column X and column Y?

Correct option is C

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Explanation:

1. Ia fibers → Muscle spindle, annulo-spiral ending
• Ia fibers are primary afferent fibers connected to the muscle spindle that detect rapid stretch and regulate muscle tone.
2. Ib fibers → Golgi tendon organ
• Ib fibers arise from the Golgi tendon organ, which monitors muscle tension and force generation.
3. II fibers → Muscle spindle, flower spray ending
• Type II fibers are secondary afferent fibers of the muscle spindle, responding to static muscle length.
4. III fibers → Pain and cold receptor
• Type III fibers (A-delta fibers) are involved in pain and temperature sensation, especially for detecting cold stimuli.

Information Booster:

1. Muscle Spindles are stretch-sensitive receptors present in skeletal muscles, which help in proprioception and muscle tone regulation. They are innervated by Ia (annulo-spiral endings) and II (flower spray endings) fibers.
2. Golgi Tendon Organs (GTOs) are found in tendons and detect changes in muscle tension. They are innervated by Ib fibers and play a crucial role in preventing excessive muscle contraction.
3. Pain and Temperature Sensation is carried by Type III (A-delta) fibers, which transmit sharp, localized pain and cold temperature sensations to the central nervous system.
4. Nerve Fiber Classification: Sensory nerve fibers are classified based on their conduction velocity and diameter. Ia and Ib are the fastest, II is intermediate, and III is slower but still myelinated.