A weak, physical, cross-link side bond that is easily broken by water or heat.

Strong chemical side bonde that joins the sulfur atoms of two neighboring cystein amino acids to create one cysteine, which joins togehter two polypeptide strands like the rungs on a ladder.

Autoimmune disorder that causes the affected hair follicles to be mistakenly attacked by a person's own immune system.

The tube-like depression or pocket in the skin or scalp that contains the hair root.

Technical term for beaded hair.

Also know as lanugo hair; short fine unpigmented and downy hair that appears on the body, with the exception of the palms of the hands and soles of the feet.

The part of the hair located below the surface of the epidermis.

Technical term for dandruff; characteerized by excessive production and accumulation of skin cells

Hair stream that forms in a circular pattern on the crown of the head.

The small, involuntary muscle in the base of the hair follicle.

Inner most layer of the hair that is composed of round cells; often absent in fine and naturally blond hair.

The portion of the hair that projects above the epidermis.