Integumentary System (skin, hair and nails) warm up: read and notebook out!

I. Functions (Physiology) of the Skin The skin has 7 functions:

I. Functions of the Skin 1. Protects the body by providing a physical barrier between the organism and the outside environment. Protects the internal organs from dehydration (drying out), injury and infection caused by viruses or bacteria invading the body. Influenza virus 

Small Pox   Chicken Pox

I. Functions of the Skin 2. Helps regulate body temperature by evaporation of water from the skin, in the form of perspiration (sweat) and by controlling the size of the blood vessels.

I. Functions of the Skin 3. Allows for sensation (feeling) because it contains nerves which sense touch, temperature and pain. A square inch of skin contains about 72 feet of nerves and hundreds of sensory receptors.

I. Functions of the Skin 4. Produces vitamin D when exposed to the sun. Without sunlight, you can get a disease called rickets.

I. Functions of the Skin 5. Changes pigmentation when exposed to the sun to protect the internal organs from ultraviolet radiation.

 Skin Cancer Skin Graft 

I. Functions of the Skin 6.Contains tissues for temporary storage of fat, glucose, water and salts that are absorbed by the blood when needed in the rest of the body.

I. Functions of the Skin 7. Can absorb drugs and other chemical substances through the skin which is useful for giving certain drugs because they can be applied directly to the skin. Nicotine Patch 

II. Structure of the Skin -The skin is made up of two basic layers: 1. Epidermis-outermost covering which is made up of epithelial cells with no blood vessels (avascular). 2. Dermis-thick layer of skin underneath the epidermis which is made up of connective tissue and is vascular (has blood vessels).

Hemorrhagic fever 

Bubonic Plague