Your hair strength and flexibility come from its coil structure, secured with three types of bonds. Hair grows from tiny stocking-like structures beneath the skin called hair follicles, which contain sheaths to protect and style it,, oil glands to condition it, and cells responsible for producing new strands.
The Hair Shaft
The hair shaft is the part of hair that lies above the skin. The hair shaft also contains pigment cells that give our locks their color and a thin layer of lipids to repel water, keeping our locks hydrated and vibrant.
An abnormal hair structure may make it fragile and easily break; external injury, genetic disorders, or internal disease can cause it. One such condition called trichorrhexis nodosa (“bubble hair”) involves transverse fractures in the hair shaft, which cause transverse dark bands to appear under polarising microscopy.
The Cuticle
The hair cuticle consists of flattened cells overlapping to protect the cortex from environmental factors, cosmetic treatments, and industrial processes that could harm it. The cuticle cells also give your locks a healthy and natural shine by reflecting light. Frequent chemical treatment, brushing, and blow drying incorrectly or repeatedly may damage the cuticle layers and leave your hair dull or dry.
Run a long strand between your fingers from tip to root to detect your hair cuticle. The strand should move more quickly toward the scalp, corresponding with individual cuticle cells.
The Medulla
The medulla is at the core of many hair fibers, providing necessary nerve signals for bodily processes like breathing and heart rate regulation. It is easily identifiable and features round elevations known as pyramids on its anterior surface. The medulla is fed by blood vessels, and blockage leads to lateral medullary syndrome, affecting speech and swallowing muscles. It also contains essential nuclei that control breathing mechanisms.
