Hair Follicle, Functions, Diseases, A Simple Guide To The Condition, Diagnosis, Treatment And Related Conditions

This book describes Hair Follicle, Functions, Diseases, Diagnosis and Treatment and Related Diseases
A Hair Follicle comprises:
1.A root made of non-keratinized cell
2.A shaft made of keratinized material.
The shaft spreads from the skin surface to the free end of the hair.
The root and its lower end are termed the hair bulb and contain the hair matrix cells.
They comprise all the part below the skin surface and lies in what is called the hair follicle.
A pointed projection of the dermis protrudes into the hair bulb and is called the papilla.
It is richly supplied with the nerves and blood vessels.
It also contains the melanin which is accountable for the pigment in the dark hair.
The human body apart from areas of glabrous skin is covered in follicles which produce thick and fine hair.
Most frequent interest in hair is directed on hair growth, hair types and hair care.
Hair is also an important biomaterial mainly made of protein notably keratin.
Life and Death of a Hair Follicle:
My name is Hairy Man the hair follicle.
I was named Hairy Man by my friends who feel that I am a hairy character.
We are found every where on the body except for the palms, soles, dorsal aspect of the phalanges of the hands and feet, the penis, the labia minora and the lips.
I began as an epithelial bud on the outer surface of an embryo.
The epithelial bud appears as a hair follicle at about 9 weeks of age of the embryo’s life.
The first follicles develop in the areas that will eventually become the eyebrows, upper lip and chin.
My Hair follicle development on body, face and scalp then occurs in successive waves beginning at fetal age of 4 to 5 months.
I appear as a scalp hair follicle about this time.
The fully mature 9-month fetus normally has all of the hair follicles that will ever develop in that person.
Later on my friends the pigment cells responsible for hair pigment were told to make my hair shaft black by their pigmentation.
At the same time I incorporate a sebaceous oil gland that will supply lubrication for my hair shaft.
Normally my hair shaft will grow the follicle will grow out at an angle relative to the skin.
Attached to me is a tiny bundle of muscle fiber called the arrector pili.
This muscle is responsible for causing the follicle to become more perpendicular to the surface of the skin, and causing my follicle to protrude slightly above the surrounding skin.
This process results in goose bumps.
Next to us are the apocrine sweat glands which produce sweat to cool the body by evaporation.
We hairs protect the skin against harmful influences.
My friends the eyebrows direct sweat away from the eyes and the nasal hairs filter the air.
We the scalp hairs and my friend the body hairs also act as a thermal regulator keeping the body and head warm.
At the same time we hairs also keep the body cool by promoting sweat evaporation.
We hairs are also the sensitive tactile organ.
We scalp hairs also provides sexual attraction.
The cycle of my hair length varies on different parts of the body.
For my friends the eyebrows, the cycle is completed in around 4 months
For me at the scalp, the cycle takes about 2–7 years to finish
DLX3 is a crucial regulator of hair follicle differentiation and cycling.
1.Anagen phase (growth) 2 – 7 years
During this phase my hair shaft grows about 1cm every 28 days
At the end of the anagen phase an unknown signal causes my follicle to enter the catagen phase.
2.Catagen phase (regressive apoptosis) 2 -3 weeks:
A club hair is formed during the catagen phase
3.Telogen phase (dropping) 3 months
The telogen phase is my dropping phase
My hair shaft is beginning to fall from the scalp
50-100 of us are shed daily!
TABLE OF CONTENT
Introduction
Chapter 1 Hair Follicle
Chapter 2 Growth of A Hair Follicle
Chapter 3 Functions
Chapter 4 Life Cycle
Chapter 5 Removal of Hair
Chapter 6 Diseases
Chapter 7 Hair Loss
Chapter 8 Life and Death Hair Follicle
Epilogue