Rooted: The wonders of hair

Written By Emman Allahgul

Med Youth Alliance | November 2025

Sometimes we all admire the hair on our heads, the coils, curls, waves and straight, but we often forget about hair as a collective system and its purposes.

Structure

Hair consists of three main structures:

• The Shaft (part of the hair you can see and style), consists of three parts: Medulla (innermost core), cortex (contains keratin and melanin, determining hair colour and strength), cuticle (outermost layer of keratinised cells protecting shaft)

• Hair root: below skin surface within follicle

• Hair follicle: tubelike structure that keeps your hair in your skin. Includes bulb (base of follicle containing dermal papilla and matrix cells), matrix (dividing cells that produce the hair shaft), dermal papilla (supplies blood and growth factors to matrix)

Hair follicles undergo cycles of growth, regression and rest.

picture from hairknowhow.com

Function

• Thermal insulation: conserves heat especially in colder environments

Example: goosebumps- we have hair erector muscles connected to our hair follicles and skin, so that when it contracts it stands up, causing what looks like goosebumps

• UV protection: scalp hair protects from ultraviolet radiation

• Sensory input: hair follicles are associated with nerve endings that respond to displacement

• Barrier/protection: eyelashes and nasal hair trap debris/pathogens from entering

Hair disorders:

• Alopecia:

Androgenetic alopecia- genetic hormone dependent hair loss

Alopecia areata- autoimmune condition causing patchy hair loss

Telogen effluvium- stress induced shedding

• Hirsutism: excess terminal hair growth in women in a male pattern distribution due to conditions such as PCOS

• Trichotillomania: psychological disorder involving compulsive hair pulling

• Folliculitis: inflammation of hair follicles mainly due to bacteria or irritation

• Grey hair: age related due to reduction in melanin production in hair follicles

image by katiecouric.com

Hair care

• Wash and condition using fingertips

• Avoid excessive massaging scalp when washing

• Use gentle shampoo

• Recommended to use conditioner as it coats the hair shaft, reducing friction which avoids breakage, frizz and split ends. Leave in conditioners also help protect hair

Avoid

• Tight hairstyles for excessive periods (can cause traction alopecia)

• avoid bristle brushes and back combing

Sources:

Hair – Anatomy, Structure & Clinical Significance | ExploreAnatomy

Integumentary System: What It Is, Function & Organs

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