Home » Hair Problems » The Anatomy of Hair: Understanding the Key Components
hair health and appearance

The Anatomy of Hair: Understanding the Key Components

Hair is not just a decorative feature; it plays a vital role in protecting the scalp and regulating body temperature. To appreciate and care for your hair properly, it’s essential to understand its basic structure. A hair strand consists of three main components: the cuticle, cortex, and medulla, each contributing to hair health and appearance in distinct ways.

The Cuticle

The cuticle is the outermost layer of the hair shaft, consisting of thin, overlapping scales or shingles. Its primary function is to protect the inner layers of the hair from environmental damage, such as UV rays, pollutants, and chemical exposure. The health and appearance of the cuticle are crucial for several reasons.


An intact and healthy cuticle acts as a shield, preventing damage and moisture loss from the inner layers. When the cuticle is damaged, the hair becomes more vulnerable to various stressors, leading to dryness and breakage.

Smoothness and Shine

When the cuticle lies flat and is free of damage, it creates a smooth surface that reflects light, resulting in a shiny and lustrous appearance. In contrast, a damaged cuticle can make hair look dull and rough.

hair strand

The Cortex

Beneath the cuticle lies the cortex, the thickest layer of the hair strand. The cortex primarily comprises a protein called keratin, which is responsible for the hair’s strength, elasticity, and color. Here’s how the cortex contributes to hair health and appearance:


The cortex provides structural integrity to the hair, making it resilient to stretching and bending. Strong, healthy hair is less prone to breakage.


The cortex’s ability to stretch and return to its original shape is essential for maintaining hair’s flexibility and preventing brittleness.


The cortex contains pigment granules that determine the hair’s color. As we age, these pigments decrease, leading to gray hair.

The Medulla

The medulla is the innermost layer of the hair shaft, and it is not always present in all hair types. This component is less understood and less prominent in hair health and appearance. It is believed to provide structural support and might help with moisture distribution.