Tendinum is a term commonly used in anatomy and physiology to describe fibrous tissue that connects muscles to bones. There are several synonyms for this term, including tendons, sinews, and ligaments. Tendons are strong, flexible cords that transmit the force of muscle contractions to the bones they attach to, while sinews are a tougher, thicker type of tendon. Ligaments, on the other hand, are bands of connective tissue that connect bones to each other, providing stability and support to joints. Despite their different roles in the body, tendons, sinews, and ligaments are all essential components of the musculoskeletal system, allowing for movement, strength, and flexibility.