What is the primary purpose of tendons in the muscular system?

The primary purpose of tendons in the muscular system is to connect muscles to bones. Tendons are strong, fibrous connective tissues that play a crucial role in facilitating movement. When a muscle contracts, the tendon transmits this force to the attached bone, which results in movement at the joint. This function is vital for all types of physical activities and allows the body to perform complex movements, from simple actions like walking to more dynamic activities such as running or jumping.

In contrast to the other options, tendons do not provide energy for contraction; that role is fulfilled by the muscle fibers themselves, utilizing energy stored in ATP (adenosine triphosphate). While they contribute to joint stability, this is not their primary role, as ligaments primarily take on that function by connecting bones to other bones. Additionally, protection of muscles from injury is typically the responsibility of the body's overall structure, including ligaments and muscles themselves, rather than the function of tendons. Thus, the connection between muscles and bones is the fundamental role of tendons in the muscular system.