Skin Physioanatomy 101

Hair Structure and Growth

It's not widely known, but dermatology is actually the specialty of skin, hair and nails.

So, we're going to go through some hair essentials - no, not a hair-flipping commercial - a breakdown of what hair actually is, and if you have hair - how it grows and naturally sheds.

What is hair?

Hair is made mostly of protein - notably keratin, among lots of other structures.

It grows from the hair bulbs (aka 'follicle') found deep in the skin within the hypodermis, forming (fortunately or unfortunately) long filaments of strong, protective hairs. As the hair grows, it forms the hair shaft and the hair that we see.

Hair serves a variety of functions, including protection from the sun and physical forces, as well as insulation and the ability to sense finer things touching the skin. When you get cold - or scared - the 'goose skin' that you see is the action of your arrector pili muscles, pulling on the hairs to make them stand 'on end'.

The colour and texture of hair varies widely among individuals, largely depending on genetics, but also on environmental factors such as level of ultraviolet light - if you're lucky enough to live somewhere with lots of sun.

There are a huge variety of conditions affecting the hair, and knowing about the different structures of the hair (bulb, sheath, shaft, sebaceous glands, etc.) helps us to better understand how our hair is functioning in particular.

Coming soon...

'A hairs breadth' - the structure of a hair

Normal hair growth - anagen, catagen, telogen