Sinew is an Old English word that means tendon. Tendons are made of strong, elastic fibrous connective tissue that connects muscle to bone. The similar material that binds bones together is a ligament.
Each long, slender muscle fiber (an individual cell) is sheathed in connective tissue. Muscle fibers are bundled into fascicles, also sheathed with connective tissue. Fascicles are bundled into muscles by the same stuff. All these casings extent beyond the muscle proper, become tightly packed together, and then blend with the material that forms the outer layer of bone, the periosteum. When a muscle contracts, it exerts its force through the tendon to the bone. The bone moves around its joint.
When I was a kid, I was given a leg of a freshly killed chicken to play with. My father showed me how to pull on the tendons to make the claws open and close.
Tendons are comprised of fibrous bundles of the protein collagen, a nonliving substance manufactured by living cells called fibroblasts. Live cells need a constant blood supply, but nonliving cells do not. Most of the substance of a tendon is nonliving, so tendons are not highly vascularized (not many blood vessels in them). This helps explain why injuries to tendons and ligaments take such a long time to heal since it is the constant flow of blood that promotes healing.
Because of the high tensile strength of tendons, animal sinews have been used throughout history as a source of thread and cordage to lash things together. It also has been used to reinforce hunting bows.
Part 7: Sinews
Note: For background on this series, please read the Introduction to the 32-Parts Project.
Each long, slender muscle fiber (an individual cell) is sheathed in connective tissue. Muscle fibers are bundled into fascicles, also sheathed with connective tissue. Fascicles are bundled into muscles by the same stuff. All these casings extent beyond the muscle proper, become tightly packed together, and then blend with the material that forms the outer layer of bone, the periosteum. When a muscle contracts, it exerts its force through the tendon to the bone. The bone moves around its joint.
When I was a kid, I was given a leg of a freshly killed chicken to play with. My father showed me how to pull on the tendons to make the claws open and close.
Tendons are comprised of fibrous bundles of the protein collagen, a nonliving substance manufactured by living cells called fibroblasts. Live cells need a constant blood supply, but nonliving cells do not. Most of the substance of a tendon is nonliving, so tendons are not highly vascularized (not many blood vessels in them). This helps explain why injuries to tendons and ligaments take such a long time to heal since it is the constant flow of blood that promotes healing.
Because of the high tensile strength of tendons, animal sinews have been used throughout history as a source of thread and cordage to lash things together. It also has been used to reinforce hunting bows.
For background on this series, please read the Introduction to the 32-Parts Project.