A tendon or sinew is a tough band of dense fibrous connective tissue that connects muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tension.
The Achilles tendon, one of the tendons in the human body (from Gray's Anatomy, 1st ed., 1858)
Micrograph of a piece of tendon; H&E stain
Magnified view of a tendon
Ossified tendon from an Edmontosaurus bone bed in Wyoming (Lance Formation)
Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesoderm, the middle embryonic germ layer. Connective tissue is found in between other tissues everywhere in the body, including the nervous system. The three meninges, membranes that envelop the brain and spinal cord, are composed of connective tissue. Most types of connective tissue consists of three main components: elastic and collagen fibers, ground substance, and cells. Blood, and lymph are classed as specialized fluid connective tissues that do not contain fiber. All are immersed in the body water. The cells of connective tissue include fibroblasts, adipocytes, macrophages, mast cells and leukocytes.
Section of epididymis. Connective tissue (blue) is seen supporting the epithelium (purple)
Hypermobility as a result of an inherited connective tissue defect.