Final answer:
Active tension in muscles is generated by muscle fiber contraction, not by the stretching of connective tissues like tendon, epimysium, perimysium, and endomysium which primarily provide support and transmit force.
Step-by-step explanation:
The statement that active tension in a muscle-tendon unit comes primarily from the stretching of connective tissue elements like tendon, epimysium, perimysium, and endomysium is false. Active tension is produced by the contraction of muscle fibers, which occurs when myosin heads in the thick filaments use energy to pull on actin in the thin filaments, leading to a shortening of the muscle fiber.
While the connective tissue elements such as the tendon, epimysium, perimysium, and endomysium do provide structure and support, their primary role is not the generation of active tension but rather the transmission of force to the skeleton and the protection and organization of muscle fibers.
The entire structure is essential for the proper functioning of muscles. The tendon attaches the muscle to the bone, allowing the generated force to move the skeleton. The epimysium is the outer layer of connective tissue around a skeletal muscle, and the endomysium is a thin connective tissue layer surrounding each muscle fiber, providing essential nutrients.