Hair growth is a natural process. Hair also touches the papilla of the body. The hairs grow on the body of a person from the root of the central part of the follicle. There is a hair bulb that surrounds the hair matrix. Nearby the follicle there are apocrine sweat glands that produce sweat and regulates the internal temperature of the body and it is a part of the thermoregulation in the process of homeostasis.
And nearby the follicle there is a sebaceous gland that is exocrine gland and it secretes oily or waxy form called sebum that makes the skin smooth and waterproof the hair and the skin of mammals. And there is an arrector pili muscle that is used to make the follicle more perpendicular to the surface of the skin of the mammals.
And hairs are all over the body except the areas of soles of feet, palms of the hand, the navel, scar areas, etc. The protein that makes up the hair are called keratin and they stimulate hair growth. Hair is stratified squamous keratinized epithelium and they are made up of a flat layer of cells whose rope-like structure filaments give strength to the hair shaft.
Hair Growth Cycle:
Hair growth occurs through the cycles of anagen, telogen, and catagen. It’s a specialized growth cycle. Every phase of this growth cycle is characterized for the hair length. Every hair on the body has its own development cycle when a cycle completes and hair’s length is increased. When the cycle completes its phases than it restarts and new hairs grow on the body. The speed rate of hair growth is o.5 inches or 1.25 centimeters per month or 6 inches or 15 centimeters per year.
Anagen: It begins in the papilla and last for three to five years. This is the phase in which hair physically grows approximately 1 centimeter per month. The duration at which hair remains in this growth stage is determined by genetics. During this phase, the cells neighbor the papilla starts to produce new hair fibers and the follicle deposit itself in the dermal layer of skin to nourish strand. Maximum 85 or 90 % of the hair of the body on the head of a person are due to anagen phase.
Telogen: During this phase the follicle remains inactive for months. In this phase the epidermal cells lining the follicle to continue to grow at normal and they assemble in the base of the hair. And they preserve the hair for its natural mechanism without demanding the other body resources required for the hair growth cycle.
10 to 15 % of the hair on the head of a person its always ready to grow at any given time.Also during this phase the follicle begins to start their growth softens the anchoring of the hair and the hair began to shed because of freeing from their roots because their roots anchoring became soften. After some time the hair shaft developed once this phase completes.
Catagen: This phase is also known as the transitional phase it allows the follicle to renew itself. After sometime the follicle weaken due to disintegration and the papilla disengages itself and rests. It cuts the hair strand off from its beneficial blood supply. When anagen phase end and then this phase starts. The sign of catagen is the break down of the melanin production in the hair bunch. And the follicular melanocytes starts to die. During this phase the hair growth doesn’t occur and the follicle pushes the terminal fibers increase upward.
It is the organ found in mammals bodies in the skin. It is found in the dermal layer of the skin. They are made up of the so many cells type that have different functions. It interacts with the hormones of the endocrine glands of the body. Follicles anchors the hair of the body into the skin.
And also connects with the immune system and the neuropeptides of the central nervous system of the body. It is a part in the process of regulation of the hair growth. For example, terminal hair grows on the scalp of the body, etc. It changes with the areas of the body. For example, it does not occur at the sole of the feet and the palm of the hand, etc.
At the base of the hair follicle there is papilla. And around the papilla there is a hair matrix. Other structure of the follicle that associates with the cup of follicle is known as infundibulum, arrector pili muscles, apocrine sweat glands and sebaceous gland. The receptors sense the position of the hair.
Hair grows faster on the body of a male than the female. Everyone is born with the 5 million follicles. Everyone have the 100,000 follicles on the scalp of the body. When a person gets older than their follicles stops growing. A person loses about 100 hairs a day.
Benefits of Hair Growth:
In head, there so many advantages of hair on the body. It protects the scalp from the cold and sun. There are unlimited hairs on the head but approximately not less than the 100,000 strands of hair. And hair shed about 50 to 100 strands in a day but new hair grow due to hair growth cycles.
In arms and in legs, the hair works like a effectors that means it works to sense the stimulus. And if it observe an insect on hand or leg so it sends message through the neurons to the brain to act immediately. And then the brain does so.
On eye, the eyelashes and the eyelids protects the eye from external invaders.
In nose, the hairs resist the air particles or dust particles or pollens, etc that are harmful for the nose of the person. Also filters the air that goes through the nose to the lungs of the body of a person.
Hypertrichosis: It is a disease in which due to rapid growth of hair on the body then is fully covered with the hairs all over the body. It can be from birth or at any age.
Treatment: Medicines like phenytoin, anticonvolusants, etc. But this is not a appropriate way to treat this disease completely. When medicines are discontinued than this disease reverses back.
Hair Loss: This is the major problem in the world now a days because everyone love their long, beautiful and natural hair on their head of the body. No one wants to become bald in this modern era of the world. Hair loss due to aging of the follicle. The breakdown of collagen that is responsible for the follicle miniaturization.
Treatment: The treatment of hair loss is that hair transplant.