integumentary system= mostly skin- why do you need this?? section 21-4 pg.591-594

Integumentary System= mostly Skin-

Why do you need this??

Section 21-4Pg.591-594

Basic Skin Facts

• Skin is the largest organ in the body• Made up of 2 layers

Epidermis-surface layer- very outside part and are actually

dead-are rubbed off and continually replaced

-Melanin-is found here, this is a pigment that makes your skin darker- this increase when exposed to UV rays (when your outside)

Dermis2nd layer, thicker layer, is where the

blood vessels, nerves, oil, and sweat glands are found-Fat cells are found underneath this

layer, which insulates your body

What are some of the jobs/function of skin??

Function/Job of Skin• Protection– Prevents physical, chemical, and diseases

• Sensory response– Nerves-tell pain, temp., pressure, etc.

• Formation of Vit. D– Is produced when skin is exposed to light– Helps absorb calcium from body

More Function/Jobs of Skin

• Regulation of Body Temp.– Blood vessels within skin can hold or release heat– Hair can help keep heat in-getting the

Goosebumps– Have 3 million sweat glands-help in releasing heat-

through perspiration-cooling the body

• Excretion of waste– Sweat glands release waste-salt and protein-urea

What happens when skin is damaged??

Damage to the skin• When epidermis is damaged- have no cells to

replace these for a while.• Can get nerves and blood vessels exposed.

• Don’t have good protection in this area, so bacteria and other items can get into the body.

• Area is red around wound is red, warm to the touch, and discolored- These are all signs of an infection

The End