Hair Anatomy

Hair is much more complicated than it appears. It helps transmit sensory information and creates gender identity. Hair is important to the appearance of men and women. There is hair on all the major visible surfaces of the body but the hair on the head is the most likely to be lost.

Structure of the hair

Before considering the scalp as a whole, it is relevant to consider the structure of the hair follicle. Hair follicles are the prize in hair transplant surgery and the skilful harvesting and replanting of them is the essence of high quality hair transplantation.

The hair follicle

For the above reason, in modern hair transplant surgery for male pattern baldness, great emphasis is placed on the follicular unit as a discrete entity.

Diagram showing a cross-section of the skin and hair follicles.

The hair follicle usually consists of between 1-4 terminal hairs with associated sebaceous glands, tiny muscles, which can make your hair stand on end and a surrounding collection of blood vessels, nerves and binding collagen fibres. It is felt that this follicular unit constitutes a distinct physiologic entity and should be respected as such. In contrast, when a hair is looked at in vertical section the follicular unit as such is less obvious. However it is useful to look at an individual hair to understand some of the terms that are commonly used when a patient is reading about androgenetic alopecia, male pattern baldness.