Integumentary system

In zootomy, the integumentary system is often the largest organ system of an animal, comprising skin, hair, feathers, scales, nails, skin glands and their products (sweat, slime). It distinguishes, separates, protects, and informs the animal with regard to its surroundings. Small bodied invertebrates of aquatic or continually moist habitats respire at their outer layer (integument). This gas exchange system, where gasses simply diffuse into and out of the interstitial fluid, is called integumentary exchange.

In botany, the integument refers to the envelope of an ovule.

The name comes from the Latin integumentum, which means "to cover".

Components
The major components of the integumentary system are the cutaneous membrane (skin), and its accessory structures (hair, nails, exocrine glands).

Cutaneous glands include:
 * Sudoriferous glands - or sweat glands
 * Sebaceous glands - oil-producing glands
 * Ceruminous glands - glands of the ear canal that produce cerumen (earwax)
 * Mammary glands - milk-producing glands located in the breasts