Diagram of a complete hair

http://www.spiritualresearchfoundation.org/spiritualresearch/spiritualityandhealth/images/Hair-ver-1-Normal.gif

ohttp://www.google.com/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&cd=1&ved=0CB4QFjAA&url=http%3A%2F%2Fwww.chem.sc.edu%2Fanalytical%2Fchem107%2Flab4_032205.pdf&ei=P87FTqPiDci2twfRt_zkCw&usg=AFQjCNHDwNwCzGiZn65NsfrWOGaFoyIRKg

o   Hair is defined as a thin, thread-like outgrowth from am follicle in skin.  It grows from the papilla and except for at its origin is made of dead cornified cells. It has a shaft that extends from above the skin and a root that is imbedded in the skin. The bottom of the root expands to form the root bulb which is composed of keratin, melanin, and trace quantities of metallic elements. These elements are deposited in the hair when it grows or from an external environment. After its growth, the follicle stays in a resting stage before it completely dies and is removed from the body. It has three main parts the cuticle, medulla, and cortex. The cuticle of a hair is the outer layer of the hair that is translucent. It covers the shaft with scales that point from the proximal to the distal end of the hair. There are three main scale structures that form the cuticle but can differ. Coronal scale structures are crown-like and are usually found in small animals with fine hair diameters.  Spinious scale structures are petal-like, triangle shaped, extend from the hair shaft and are never found in human hairs. Imbricate scale structures are flattened and are often found in many animal and human hairs. The medulla of the hair is the central core of cells it contains and is filled with air. Under transmitted light it looks black, with reflected light white, and clear if it is filled with mounting medium or other substance. The cortex of a hair is its main body of elongated and fusiform cells. It can consists of cortical fusi, pigment granules, and/or ovoid bodies. Cortical fusi are irregular-shaped airspaces often found near the root. Pigment granules are small, dark, solid structures that have a granular appearance. Ovoid bardies are fairly large, solid structures and are spherical or oval shape.

http://www.chem.sc.edu/analytical/chem107/lab4_032205.pdf