Cortex

The portion of hair that extends beyond the surface of the skin. It contains three layers: the cuticle, cortex, and medulla (not always present).

A protein and the major component of the cuticle and cortex layers of hair; the same protein is found in nails, feathers, claws, and hooves.

One of the three major nutrients (along with carbohydrates and fats). It is used by the body for building and repairing tissues. Protein is derived primarily from animal sources…

The part of the cerebral cortex involved in processing information, rather than movement or sensory experiences.