Question

For good tendon healing to take place, there needs to be a high level of elastin.

True or False

Answer 1

Ans: False, For good tendon healing to take place, there does not need to be a high level of elastin.

Explanation: Tendons are dense fibrous connective tissues responsible for connecting muscle to bone. It is mostly composed of collagen fibers arranged parallely to each other and organised into fascicles. Collagen makes up about 80% of the dry weight of tendon with elastin only making about 2% dry weight of tendon. Healing of tendon involves three stages: inflammation, proliferation and remodeling. In the inflammatory phase, cells such as neutrophils along with monocytes, macrophages are recruited to the injured tissue for phagocytosis of the necrotic tissue. These cells also release various cytokines and growth factors that promote the proliferation of tenocytes which go on to synthesize collagen. In the remodeling stage, collagen fibers align in the direction of mechanical stress and crosslinking between fibers also occurs. This allows the tissue to turn stiffer and gradually, a scar tissue is formed at the site of injury. Thus, high levels of collagen are necessary for good tendon healing and not elastin. Moreover, elastin tends to discourage cell attachment and growth which are a vital part of the healing process of any kind of tissue including tendon.