The Integumentary System - by Jacob Marsh

The Integumentary System is made up of hair, fingernails, and the most important organ in the human body, skin. It provides the body with a barrier to keep out foreign materials.
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Structure and Function:

  • Epidermis- the epidermis is the outside layer of the skin. It is composed of dividing cells called keratinocytes which are produced by germ cells in the hair follicle.
  • Dermis- the dermis is the middle layer of the skin.
  • Capillaries- microscropic blood vessels that provide nutrients and oxygen.
  • Sweat Glands- secrete sweat as a way to cool the body down.
  • Subcutaneous layer- located below the dermis and contains fat cells and collective membranes.

Enzymes and Hormones:

  • Melanin- a pigment that give the skin color and protects the underlying layers against damage from U.V rays
  • Cerumen- substance released in the ear canal of humans and other mammals. Protects body from bacteria, fungi, and insects.


Skin functions in homeostasis include protection, regulation of body temperature, sensory reception, water balance, synthesis of vitamins and hormones, and absorption of materials.
  • When the body temperature rises, the hypothalamus sends a nerve signal to the sweat-producing skin glands, causing them to release about 1-2 liters of water per hour, cooling the body.
  • When body temperature falls, the sweat glands constrict and sweat production decreases. If the body temperature continues to fall, the body will engage in thermiogenesis, or heat generation, by raising the body's metabolic rate and by shivering.


Integumentary system is the organ system that protects the body from damage, comprising the skin and its appendages . The integumentary system has a variety of functions; it may serve to waterproof, cushion, and protect...In other words, the primary function of the integumentary system is to protect the other systems from the external environment. It is closely aligned with the nervous system, and can even be thought of as an extension of it.


webster's encyclopedia

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