Hair is made up of proteins known as Keratin, this same protein makes our nails. Our hair is made up of 3 layers i.e. Medulla, Cortex and Cuticle. Medulla is the inner most layer of the hair and is present only in large thick hair, the next layer or the middle layer is cortex which provides colour and texture to the hair.
Cortex is covered by a thin layer called cuticle which is the outer most layer of the hair, it protects the cortex. Our hair grows below the surface of the skin, the root of the hair is enclosed within the hair follicle. Inside the hair follicle, at the base is the dermal papilla which is fed by the blood vessels. These blood vessels provide nourishment for new hair growth.
The blood vessels also provide oxygen, energy and amino acids for growth. Our hair gets its colour from melanin pigments, these melanocytes are present in the upper part of the papilla. The part of the share that is above the skin is known as hair shaft and consists of dead cells that have been converted into keratin. It also has some binding material with small amount of water.
This hair is lubricated with the natural oil produced by our scalp known as sebum. Sebum is produced by the sebaceous glands of our hair follicles, too much or too less of sebum can cause hair problems hence sebum production should be regulated.
There are 3 cycles in hair growth namely; Anagen, Catagen and Telogen. Your hair goes through all the 3 stages and then falls out if it falls out within thses 3 cycles then the hair fall is considered to be abnormal. The Anangen phase lasts for about 1000 days and the hair grows in this stage, later in Catagen stage the hair stops growing and this phase lasts for 10 days. Finally in the Telogen stage, the hair rests and then falls out. This stage is also known as resting stage and lasts for about 100 days.