Integumentary system

The integumentary system is everything covering the outside of an animal's body. This account is written mostly with people in mind, but it applies more widely.

The integument means skin, hair, scales, nails, sweat glands and their products (sweat and mucus). The name comes from the Latin integumentum, which means 'a covering'.

 The integumentary system 
Skin, hair, scales, feathers and nails make up the integumentary system.

 Skin 
There are two layers of skin: 
 Epidermis - This is the top layer of the skin and is made of dead cells. The cells are shed all the time, but new ones are always being made, so people never lose any skin. It has sweat pores.
 Dermis - This is the second layer of skin. It has touch receptors, and oil and sweat glands. It makes skin stretchy.
 Subcutaneous tissue (The subcutaneous tissue is not part of the skin, but it is in the integumentary system)

 Glands 
There are four types of glands
 Sweat glands - make sweat to control temperature
 Sebaceous glands - make oil
 Ceruminous glands - make ear wax
 Mammary glands - make milk and are only in women

 Functions 
The integumentary system has lots of different functions. It:
 Protects the body’s internal organs
 Protects the body against bacteria
 Protects the body from dehydration
 Protects the body against sunburns
 Stores water, fat, and vitamin D

 Problems 
Here is a list of skin problems:
 Acne, when pimples form on the skin
 Sunburn, when UV radiation from the sun burns your skin
 Skin cancer, caused by getting too many sunburns.
There are other skin problems that are less common.

 References 
 Kardong, Kenneth V. 1998. Vertebrates: comparative anatomy, function, evolution. McGraw-Hill. ISBN 0-07-115356-X/0-697-28654-1 

 Other websites 
 Aquatic Path  Details of the integumentary system of the fathead minnow
 An article written for children