Stretch in a muscle is monitored by a stretch receptor called a muscle ______.

• A. spindle
• B. tendon
• C. fiber
• D. fascicle

Answer: (A)

Verified step by step guidance

1. Understand the function of stretch receptors in muscles: Stretch receptors are specialized sensory structures that monitor changes in muscle length and tension, helping maintain posture and coordinate movement.
2. Identify the correct anatomical term for the stretch receptor: The muscle spindle is a sensory receptor located within the muscle that detects stretch and sends signals to the central nervous system to initiate a reflex response.
3. Differentiate between the options provided: 'Tendon' refers to connective tissue that attaches muscle to bone, 'fiber' refers to individual muscle cells, and 'fascicle' refers to a bundle of muscle fibers. None of these are sensory receptors.
4. Recognize the role of the muscle spindle: Muscle spindles are embedded within the muscle and are sensitive to changes in length, making them the correct answer for monitoring stretch.
5. Conclude that the correct answer is 'spindle' based on its function and anatomical location.