Here's a breakdown of its structure:
* Cuticle: The outermost layer of the hair shaft, composed of overlapping scales like shingles on a roof. This layer protects the inner layers and gives hair its shine.
* Cortex: The middle layer and the thickest part of the hair shaft. It contains pigment granules that give hair its color and keratin, a strong protein that determines hair's strength and texture.
* Medulla: The innermost layer of the hair shaft, which may be absent in fine hair. It's a soft, spongy core that helps insulate the hair.
Here are some key things to remember about the hair shaft:
* It's dead tissue and doesn't have its own blood supply.
* It grows from the hair follicle, which is located beneath the skin surface.
* Its shape and structure determine the hair's texture (straight, curly, wavy).
* Its color is determined by the amount and type of melanin in the cortex.
Understanding the hair shaft helps us understand how hair works and what factors affect its appearance and health.