Integumentary Integumentary SystemSystem(skin, hair and nails)(skin, hair and nails)

warm up: read and warm up: read and notebook out!notebook out!

I. Functions (Physiology) I. Functions (Physiology) of the Skinof the Skin

The skin has 7 functions:The skin has 7 functions:

I. Functions of the SkinI. Functions of the Skin

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

Influenza virus

Small Pox

Chicken Pox

I. Functions of the SkinI. Functions of the Skin

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

I. Functions of the SkinI. Functions of the Skin3. Allows for sensation (feeling) 3. Allows for sensation (feeling)

because it contains nerves because it contains nerves which sense touch, which sense touch, temperature and pain. temperature and pain. A A square inch of skin contains square inch of skin contains about 72 feet of nerves and about 72 feet of nerves and hundreds of sensory hundreds of sensory receptors.receptors.

I. Functions of the SkinI. Functions of the Skin4. Produces vitamin D when 4. Produces vitamin D when

exposed to the sun.exposed to the sun. Without sunlight, you can Without sunlight, you can get a disease called get a disease called rickets.rickets.

I. Functions of the SkinI. Functions of the Skin

5. Changes pigmentation when exposed to 5. Changes pigmentation when exposed to the sun to protect the internal organs the sun to protect the internal organs from ultraviolet radiation.from ultraviolet radiation.

Skin Cancer

Skin Graft

I. Functions of the SkinI. Functions of the Skin

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

I. Functions of the SkinI. Functions of the Skin

7. Can absorb drugs and other chemical 7. Can absorb drugs and other chemical substances through the skin which is substances through the skin which is useful for giving certain drugs because useful for giving certain drugs because they can be applied directly to the skin.they can be applied directly to the skin.

Nicotine Patch

II. Structure of the SkinII. Structure of the Skin

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

Hemorrhagic fever

Bubonic Plague