What is the structure of hair and how does it grow?
Hair is an important component of many people's appearance, as well as a way for them to show their individuality. For example, hair acts as a barrier to inhibit the sun's rays from penetrating our scalps. Eyelashes and brows protect our eyes from irritants including pollen, dust, and perspiration. Many of the pathogens we encounter are kept at bay by our own body's hair on our noses and ears. The hairs on our bodies rise when it's chilly, trapping the warm air generated by our bodies close to our skin, like a blanket of warmth.
what are different types of hair?
Our entire body is covered in hair, save for a few areas, such as the palms of our hands or the soles of our feet. Vellus hairs (peach fuzz) and terminal hairs (longer and thicker) are the two most common forms of hair. The hair on your head, face, eyelashes, eyebrows, pubic area, chest, and belly are all examples of terminal hairs.
You have a different amount of each type of hair based on your age, gender, and more. Vellus hair is common in children's bodies, for example. Women have 30 percent terminal hair on their bodies, compared to 90 percent in men.
The structure of hair:
In addition to the hair shaft and the hair root, every hair has two parts: the follicle. The shaft is the section of the hair that protrudes from the skin and is visible to the naked eye. The hair follicle is located in the epidermis and extends down into the dermis. Sebaceous glands and the follicle (a sheath of skin and connective tissue) surround it.
The arrector pili, a small muscle linked to each hair follicle, is responsible for causing the hair to stand up. The hair follicle is also the final resting place for a large number of nerves. These nerves detect even the tiniest movement of hair and are extremely sensitive.
The hair root swells into a spherical hair bulb at the hair's base. It is located at the base of each hair bulb and provides blood to the hair follicles. In the hair bulb, near to the papilla, new hair cells are continually being formed.
How does hair grow?
The hair follicle produces new cells continually. These cells harden as a result of adhesion. From this clump of hardened hair cells, a whole strand of hair is formed. The hair is eventually forced out of the skin as new, hardened cells continue to connect to it from below. One hair on your head grows roughly 1 centimeter per month in this manner. Hair on the face, including eyelashes, brows, and beards, grows more slowly than the hair on other parts of the body.
The cross-sectional shape of hair determines whether it is straight or curly. The hair grows out of the skin in a circular shape. Hair will be curlier if the cross-section is more oval-shaped.
The amount of melanin in the hardened cells determines the color of the hair. A person's values and priorities might shift dramatically over their life. As we age, the amount of melanin in our skin and hair declines, which causes the hair to become white and lose its color. Hair on a person's head can eventually go gray or white, depending on their original hair color and the number of white hairs that sprout.
The hair follicle life cycle:
The hair grows longer as long as the hair bulb is producing new hair cells. The anagen phase refers to this stage of growth. Approximately 90% of a person's hair is in this growth phase at any given moment.
Hair's growth phase might be longer or shorter depending on where it grows on the body: If you don't trim your hair throughout the growth phase, it can reach a length of over a meter in just a few years. Eyelashes, brows, nasal hair, and ear hair all have a brief growth cycle. There are only approximately 100 to 150 days in which those hairs can grow, so they won't be very long.
The hair root splits from the papilla near the end of the growing phase. When the catagen phase begins, a transitional period lasting two to four weeks begins. The blood supply to the hair is cut off in the telogen phase, which is the ultimate resting stage after it has completely split from the papilla. Hair grows out of the skin throughout time till it falls out. Resting might extend for months at a time.
New hair cells multiply at the base of the "empty" hair follicle, and the growth phase of the hair growth cycle is restarted.
What causes increased hair loss?
Because follicles are continually resting, hair follicles will continue to fall out. An average adult loses between 70 and 100 hairs per day. Natural hair loss isn't obvious because new hairs are constantly growing in and replacing the old ones.
Hair loss
can increase significantly if the damage is done to hair roots during the
growth phase or if a large number of hairs enter the resting phase at once.
That area of skin will go bald if no new hair grows to replace the existing
hair. There is no difference in the size of the bald area and the extent to
which it affects scalp or body hair when describing alopecia. Some kinds of
alopecia areata might result in hair regrowth. However, permanent baldness is possible,
as evidenced by the common occurrence of male pattern baldness (male pattern
hair loss).