What detects the tension that results during muscle contractions?

The neuromuscular junction is the synapse between a motor neuron and a muscle fiber where nerve impulses are transmitted to trigger muscle contraction. While it facilitates communication between nerves and muscles, it does not detect tension; rather, it is responsible for initiating muscle movements.

The substantia nigra is a brain structure involved in the regulation of movement and coordination, primarily associated with the production of dopamine. Although it plays a role in motor control, it does not directly detect muscle tension, making it unrelated to the sensing of tension during muscle contractions.

Muscle spindles are sensory receptors located within muscles that detect changes in muscle length and the rate of stretch. While they contribute to the reflexes that adjust muscle tone, they primarily sense stretch rather than the tension generated during contractions, thus differentiating their function from that of the Golgi tendon organ.