Massage & Bodywork Licensing Examination (MBLEx)

Which of the following structures is responsible for detecting the amount of tension within a muscle?

1. Muscle spindle

2. Golgi tendon organ

3. Perimysium

4. Sarcomere

The correct answer is: Golgi tendon organ

The Golgi tendon organ is the structure responsible for detecting the amount of tension within a muscle. These specialized receptors are located at the junctions between muscles and tendons. When muscle tension increases, the Golgi tendon organs are activated, providing important feedback to the central nervous system regarding the force of muscle contractions. This information helps to regulate muscle coordination and protect against excessive force that could lead to injury. In contrast, muscle spindles are involved in detecting changes in muscle length and the rate of change, rather than tension. The perimysium is a type of connective tissue that surrounds and supports bundles of muscle fibers but does not have a role in detecting tension or providing sensory information. Sarcomeres are the functional units of muscle contraction, responsible for the shortening of muscle fibers during contraction, but they do not detect tension. Understanding these differences is crucial for grasping how the sensors within the musculature communicate sensory information about the body's position and state to the nervous system.