ligaments

Meaning: Ligaments are bands of dense regular connective tissue made mainly of parallel collagen fibers secreted by fibroblasts. They span a joint, connect one bone to another, hold the bones in alignment, and limit movement beyond the normal range. Parallel collagen gives high tensile strength along the direction of pull with little stretch, although a few ligaments contain more elastic fibers. Ligaments are passive restraints and do not contract.

On the MCAT: Skeletal system questions ask you to match a structure to its role. A bone-to-bone connection at a joint points to a ligament; muscle-to-bone points to a tendon; a smooth, cushioning, avascular surface at the bone ends points to cartilage. A passage about a joint injury may ask you to predict the result: a torn ligament causes joint instability or excessive movement, whereas a torn tendon weakens the transfer of muscle force to the bone.

Common confusion: Students swap ligaments and tendons. Both are dense, collagen-rich connective tissue, so the tissue type does not separate them; the attachments do. Ligaments link bone to bone, and tendons link muscle to bone. Ligaments are also not cartilage and not muscle.