Sinew

Sinew
File:Tendon.png Illustration of a sinew (tendon) connecting muscle to bone
Details
System	Musculoskeletal system
Function	Connects muscle to bone
Identifiers
Latin	nervus
TA98
TH	{{#property:P1694}}
TE	{{#property:P1693}}
FMA	{{#property:P1402}}
Anatomical terminology

Sinew, commonly referred to as a tendon, is a tough band of fibrous connective tissue that usually connects muscle to bone and is capable of withstanding tension. Sinews are similar to ligaments; both are made of collagen. Ligaments join one bone to another bone, while tendons connect muscle to bone.

Structure

Sinews are composed primarily of collagen fibers, which are organized into parallel bundles. This structure allows them to transmit the force generated by muscle contraction to the bone, facilitating movement. The collagen fibers are produced by fibroblasts, which are specialized cells found within the tendon.

The outer layer of a tendon is called the epitenon, which is a thin sheath that allows the tendon to move smoothly against surrounding tissues. Beneath the epitenon is the endotenon, which contains blood vessels, nerves, and lymphatics that supply the tendon.

Function

The primary function of sinews is to transmit the force generated by muscle contraction to the bone, thereby enabling movement of the skeleton. They also play a role in absorbing external forces to protect muscles from injury.

Clinical Significance

Sinews can be subject to various injuries and conditions, such as:

• Tendinitis: Inflammation of the tendon, often due to overuse.
• Tendinosis: Degeneration of the tendon’s collagen in response to chronic overuse.
• Tendon rupture: A complete tear of the tendon, which can occur due to acute injury or chronic degeneration.

Treatment for tendon injuries may include rest, physical therapy, anti-inflammatory medications, and in severe cases, surgery.

Also see

• Ligament
• Muscle
• Collagen
• Fibroblast
• Tendinitis