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 forthree to five years. This is the phase in which hair physically growsapproximately 1 centimeter per month. The duration at which hair remains inthis growth stage is determined by genetics. During this phase, the cellsneighbor the papilla starts to produce new hair fibers and the follicle deposititself in the dermal layer of skin to nourish strand. Maximum 85 or 90 % of thehair of the body on the head of a person are due to anagen phase.
Telogen: During this phase the follicleremains inactive for months. In this phase the epidermal cells lining thefollicle to continue to grow at normal and they assemble in the base of thehair. And they preserve the hair for its natural mechanism without demandingthe other body resources required for the hair growth cycle.
10 to 15 % ofthe hair on the head of a person its always ready to grow at any giventime.Also during this phase the follicle begins to start their growth softensthe anchoring of the hair and the hair began to shed because of freeing fromtheir roots because their roots anchoring became soften. After some time thehair shaft developed once this phase completes.
Catagen: This phase is also known as thetransitional phase it allows the follicle to renew itself. After sometime thefollicle weaken due to disintegration and the papilla disengages itself andrests. It cuts the hair strand off from its beneficial blood supply. Whenanagen phase end and then this phase starts. The sign of catagen is the break down of the melanin production in the hair bunch. And thefollicular melanocytes starts to die. During this phase the hair growth doesn’toccur and the follicle pushes the terminal fibers increase upward.
It is theorgan found in mammals bodies in the skin. It is found in the dermal layer of theskin. 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. Folliclesanchors the hair of the body into the skin.
And also connects with the immune system andthe neuropeptides of the central nervous system of the body. It is a part in the process of regulation ofthe hair growth. For example, terminalhair grows on the scalp of the body, etc. It changes with the areas of thebody. For example, it does not occur at the sole of the feet and the palm ofthe hand, etc.
At the baseof the hair follicle there is papilla. And around the papilla there is a hairmatrix. Other structure of the follicle that associates with the cup offollicle is known as infundibulum, arrector pili muscles, apocrine sweat glandsand sebaceous gland. The receptors sense the position of the hair.
Hair growsfaster on the body of a male than the female. Everyone is born with the 5million follicles. Everyone have the 100,000 follicles on the scalp of thebody. When a person gets older than their follicles stops growing. A personloses about 100 hairs a day.
Benefits of Hair Growth:
In head, there so many advantages of hair onthe body. It protects the scalp from the cold and sun. There are unlimitedhairs 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 hairgrowth cycles.
In arms and in legs, the hair works like a effectors that means itworks to sense the stimulus. And if it observe an insect on hand or leg so itsends message through the neurons to the brain to act immediately. And then thebrain does so.
On eye, the eyelashes and the eyelids protects the eyefrom external invaders.
In nose, the hairs resist the air particles ordust 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 aperson.
Hypertrichosis: It is a disease in which due torapid growth of hair on the body then is fully covered with the hairs all overthe 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 diseasecompletely. When medicines are discontinued than this disease reverses back.
Hair Loss: This is the major problem in theworld now a days because everyone love their long, beautiful and natural hairon their head of the body. No one wants to become bald in this modern era ofthe world. Hair loss due to aging of the follicle. The breakdown of collagenthat is responsible for the follicle miniaturization.
Treatment: The treatment of hair loss is that hair transplant.