The integumentary system includes your skin, hair, nails, and glands. This system forms a physical barrier between your body and the external environment. It protects you from harmful pathogens and chemicals while playing important roles in regulating body temperature and healing wounds.

The different parts of the integumentary system work in harmony to ensure proper function. Understanding each component—and how to care for it—can help you maintain strong, effective protection from external threats.

Anatomy of the Integumentary System

The integumentary system makes up the body’s outermost layer, primarily consisting of the skin, which is the largest organ in the human body. It also includes skin-derived structures like hair, nails, sweat glands, and oil glands.

skin

The skin covers your entire body, weighs about six pounds, and is around two millimeters thick. Its thickness and texture vary by location—for example, the soles of your feet are thicker than the thin skin on your arms.

Skin is composed of three layers: the epidermis, dermis, and hypodermis. The epidermis is the outermost layer, offering tough protection. Beneath that, the dermis contains nerves, blood vessels, hair follicles, and glands. The deepest layer, the hypodermis, holds fat and connective tissue and connects the skin to your muscles.

nails

Nails protect the tips of your fingers and toes. They are primarily made of keratin, a durable protein. Nails grow from new cells produced in the nail matrix and push out older cells. The visible part of the nail is the nail plate, and the white half-moon shape is called the lunula. Fingernails grow faster than toenails.

hair

Hair grows from follicles located in the dermis, though the strands extend outward from the epidermis. Hair covers most of the body except for the palms, soles, lips, and select genital areas. Tiny muscles called arrector pili are attached to hair follicles and help make the hair stand on end.

glands

The skin contains exocrine glands, including sweat (sudoriferous) and oil (sebaceous) glands.

  • Eccrine glands are spread throughout the body and produce sweat to help regulate temperature.

  • Apocrine glands are found in the armpits and pubic area and produce a thicker, milkier sweat.

Sebaceous glands produce sebum, an oily substance that forms a protective film over the skin.

What Does the Integumentary System Do?

The integumentary system's primary role is to protect your body. Its parts work together to guard against injury, infection, and external threats. The system also aids in wound healing and body temperature regulation.

skin

  • Detects sensations like pain, heat, and cold

  • Cushions the body through the hypodermis

  • Blocks harmful microbes

  • Helps synthesize vitamin D from sunlight

hair

  • Shields the skin

  • Enhances sensory perception

  • Helps regulate temperature

  • Protects sensitive areas like eyes, ears, and nose

nails

  • Provide protection for fingertips and toes

  • Support fine motor function

  • Improve tactile feedback

glands

  • Create a barrier against microbes

  • Help retain moisture

  • Contribute to skin lubrication and immunity

Associated Conditions

Given the integumentary system’s wide range of responsibilities, many conditions can affect it directly or show symptoms through the skin, hair, nails, or glands.

skin

  • Acne: Caused by blocked pores filled with oil, bacteria, and dead skin cells

  • Atopic dermatitis: Leads to red, itchy, inflamed skin

  • Ichthyosis: Characterized by dry, scaly, and itchy skin

  • Psoriasis: An autoimmune condition that causes rapid skin cell growth, leading to thick, inflamed patches

  • Pemphigus: An autoimmune disorder causing skin and mucous membrane blistering

  • Rosacea: Causes chronic redness, especially on the face

  • Skin cancer: Often linked to UV exposure, it's the most common cancer type

  • Scleroderma: Results in hardened patches of skin and may damage internal organs

nails

  • Beau's lines: Horizontal grooves across the nails indicating growth interruption

  • Clubbing: Rounded nails, which may point to underlying heart, lung, or liver conditions

  • Pachyonychia congenita: A genetic disorder causing thickened nails and painful skin

  • Paronychia: Nail infection causing redness or greenish discoloration

  • Onychomycosis: Fungal nail infection

  • Nail psoriasis: May appear as pitting, discoloration, or crumbling of the nails

hair

  • Alopecia areata: An autoimmune condition that causes hair to fall out in patches

  • Lichen planopilaris: Leads to scarring and permanent hair loss

  • Hair shaft disorders: Make hair more prone to breakage or alter its texture and appearance

glands

  • Hyperhidrosis: Causes excessive sweating

  • Steatocystoma multiplex: A rare condition where oil-filled lumps form under the skin

  • Sebaceous hyperplasia: Involves small, benign bumps from enlarged oil glands

Diagnostic Testing

When a healthcare provider suspects a disorder of the integumentary system, they may order several diagnostic tests.

blood tests

Used to detect vitamin deficiencies, hormone imbalances, autoimmune markers, and thyroid issues.

skin biopsy

A small skin sample is removed and analyzed to diagnose rashes, cancer, or infection.

skin scraping

The outer skin is gently scraped and examined under a microscope, especially for fungal infections.

wood lamp examination

Uses ultraviolet light to detect bacterial or fungal skin infections.

pull and tug test

Hair is gently pulled to determine the rate of hair loss.

card test

A felt card is used to observe new hair growth.

trichometric analysis

A digital tool assesses scalp health and hair density.

fungal culture

Used to confirm fungal infections in the hair or on the scalp.

Tips for Keeping Your Integumentary System Healthy

Maintaining the health of your skin, hair, nails, and glands is essential to the integumentary system’s function.

  • Wear sunscreen daily and avoid tanning beds

  • Wash hands frequently and avoid touching your face

  • Use products designed for your skin and hair type

  • Stick to gentle products like cleanser, sunscreen, and moisturizer

  • Avoid over-washing dry hair; use sulfate-free shampoos

  • Use conditioner and avoid alcohol-based hair products

  • Trim nails straight across and avoid cutting cuticles

  • Wear well-fitting footwear

  • Protect your feet in public showers or pools

  • Soak thick toenails before trimming

  • Keep nails clean and dry

Regular skin self-examinations and professional skin checks are key. Early detection of skin cancer increases treatment success. Many other skin conditions can also be treated if caught early.

A Quick Review

The integumentary system includes your skin, hair, nails, and glands, and serves to protect your body. It also helps regulate temperature, heal wounds, and support sensory function.

Various conditions can affect this system, including acne, rosacea, alopecia, and nail infections. Diagnostic tests can help identify problems, and proper care—including hygiene and sun protection—keeps the system functioning effectively.