The Physiology of Hair – Hair Structure and Growth

A better understanding of the physiology of hair will provide a clearer picture of what happens to the hair and hair follicles during hair loss, and more specifically how Androgenetic Alopecia evolves. Let’s take a closer look at hair anatomy and physiology.

The structure of hair – What is hair made of?

Hair is mainly made up of a protein called Keratin, and comprises of different components: The root of the hair, which is enclosed in the hair follicle, is submerged in the dermis of the skin (about 2 – 5mm below the skin), ending at the base of the hair follicle (the bulb). The dermal papilla cells at the base of the hair follicle help nutrients in the blood to reach the hair follicle, which is essential for hair growth. The visible part of a hair, is called the hair shaft, and comprises of three layers:

  • The cuticle: The outer layer of the hair shaft is called the cuticle, and consists of scale-like overlapping cells, that are flat and colorless. The ultimate strength of your hair is determined by this outer layer, and it can be damaged by excessive heat, sun, harsh brushing and other forms of mechanical and chemical manipulation etc.
  • The cortex: The middle layer of the hair shaft is called the cortex, and it formed out of elongated cells filled with keratin (protein) that are joined together. This makes your hair flexible, and adding to its tensile strength. This is also where the hair pigment (melanin) that determines your hair color resides. The cortex will also determine whether you have straight or curly hair.
  • The medulla: The inner layer of the hair shaft is called the medulla. This section is made up of thin cells and air bubbles.


Help keep your hair healthy

The first thing you can do to maintain healthy hair, is to get enough vitamins and minerals each day by following a healthy and balanced diet. Proteins and iron are essential for hair growth. A change in diet can cause hair shedding (Telogen Effluvium). Read more about how your diet can cause hair loss, and what food to include to ensure optimal hair growth.

What causes hair loss?

There are many causes of hair loss. However, the most commonly seen hair loss is Androgenetic Alopecia (male / female pattern hairloss). This hair loss condition is caused by male hormones that bind with Androgen Receptors on certain hair follicles causing a reaction that results in miniaturization of hair follicles. Read more about the causes and process of Androgenetic Alopecia, and how this condition can be treated.

Book a consultation with Dr. André Nel at the Hair, Skin & Wellness Clinic in Dublin to get the best solution for your hair loss condition.