Hair

Main article: Human body

100-150 thousand hair follicles

In humans, there are on average about 100-150 thousand hair follicles in the scalp. If 100-150 hairs fall during the day, such a loss is within the normal range, and it practically goes unnoticed.

Hair structure

Hair usually consists of 3 layers - cuticular, cortical and core (may be absent). 

Cells of the cortical layer contain the pigment melanin, which gives the hair a different color.

Grey hair

Main article: Gray hair

3 phases of hair growth or why hair on the head is longer than other areas of the body

Each hair on our body is born, grows and dies according to the pattern of hair follicle growth cycle. These cycles have differences for different parts of the body. For example, the growth cycle of the hair follicles of the head is longer than the axillae.

The hair follicle growth cycle consists of three phases: 1) anagen - period of active hair growth; 2) catagen - period of growth arrest and onset of degeneration; 3) telogen - the period of death and rejection of hair follicles.

The length of the hair is determined by the amount of time it stays in the anagen phase: the longer the hair, the longer this phase.

The hair papilla is reduced; the cells of the bulb of hair stop dividing, and it horns, the root separates from the papilla and extends to the level of the ducts of the sebaceous glands. The remainder of the papilla also moves up to the level of sebaceous glands.

A person has 50-90 days between the fall of the old and the appearance of a new hair.

Hair loss

The harms of smoking

Cigarette smoke contains more than 5,000 toxic and carcinogenic chemicals and heavy metals. Resinous substances, chromium, arsenic, lead, cadmium, formaldehyde, dioxin, benzene, nitrosamines and radioactive polonium are just some of them. They damage DNA in the hair follicle, cause inflammation and scarring of the follicle, and block the growth-promoting effect of estrogen.

In addition, the blood supply to the hair root deteriorates and the result is that we get hair loss. Naturally, if you quit smoking, there is every chance that the quality of hair will improve significantly and the formation of a "smoker's bald head" can be avoided.

Hair care

Will hair be salted more if washed more often?

No, it's a myth. Located in the dermis, on the second, "underground," floor of our skin, the sebaceous glands do not know at all what is happening there upstairs, and tirelessly supply lard to the hair canal, no matter how often you wash your head.

Therefore, there is nothing to object to the daily gentle washing of hair.

Body hair

Pilomotor reflex lifts hairs on body

The reflex leading to "goose skin" is called the pilomotor reflex.

As a result of stimulation of sensational peripheral nerves emanating directly from the spinal cord, autonomic peripheral nerve endings are excited, which are responsible for the contraction of the smooth muscle of the hair follicles. By contracting, follicle muscles raise hairs on the body.

Disorders in the spinal cord lead to loss of body hair

A fracture or other serious disorders in the spine can affect the state of hair growth.

For 2020, scientists still cannot thoroughly explain how a violation of the spinal cord affects the disappearance of body hair.

Hair transplant

Main article: Hair transplant

History

2022: Rebundle starts massively selling banana fibre hair for build-up

On January 17, 2022, Rebundle announced the raising of $1.4 million in investments, thanks to which it will be able to launch full-scale production of plant-based hair. The investment will also be used to expand the team within the company, to increase the supply chain, as well as to refine logistics for the delivery of their goods. Read more here.