The Integumentary System in Health and Disease

The integumentary system includes skin, hair, and nails, and is designed to help protect our bodies.

What are some ways the integumentary system protects us?

The skin is made up of two layers: 1.The Dermis2.The Epidermis

The epidermis is the outermost layer of skin. Cells of the epidermis are constantly being lost and replaced.

Keratin is a protein found on the outer layer of skin. It is waterproof, and serves to thicken and protect the skin.

Hair and nails are made up of keratin.

Um, that's a lot of keratin.

Cells in the epidermis produce melanin, a dark pigment that colors skin.

The amount of melanin you produce determines your skin color and hair color.

Some people develop spots of melanin.

The dermis is a thick layer of skin that contains connective tissue, blood vessels, hair follicles, nerve endings, and the subcutaneous layer of fat (adipose tissue).

When the skin expands rapidly, such as during growth spurts, pregnancy, or weight gain (and sometimes even weight loss), the epidermis can tear.

These tears create striations, called "stretch marks."

Quick Review

• What are the two main layers of skin?

• What protein covers the skin, and makes up hair and nails?

• What causes variations in skin and hair color?

• What causes stretch marks?

Appendages of the Skin

The sweat glands are located in the epidermis and subcutaneous layer.

Ceruminous glands, located in the ear canal, produce cerumen.

Sebaceous glands produce oily secretions, called sebum, that lubricates the skin and hair.

Before birth, babies secrete vernix caseosa from their sebaceous glands. The vernix protects the baby's skin while it floats in the aminotic fluid.

Bathe me!Just kidding. It's okay not to wash the vernix off. It moisturizes and protects baby's skin.

Sometimes, though, our helpful sebaceous glands get blocked with sebum and keratin, and form blackheads.

Infected sebaceous glands form pimples.

Hair

Most of our bodies are covered with hair. The majority of it is fine, thin hair that is barely visible.

Hair is not alive :) It is made up of keratin, and formed within the hair follicle.

Attached to hair follicles is a small, involuntary muscle called the arrector pili muscle. When the muscle contracts, the hair is raised.

Animals do it, too.

A person's hair can tell you a lot about their overall health.

alopecia/autoimmune disease

malnutrition

thyroid disorders or polycystic ovaries

Nails, which are also made of keratin, are also not living structures.

Nails protect the ends of the fingers and toes and serve many other functions.

The condition of a person's nails can tell you a lot about their overall health.

indicates heart disease:

Indicates alopecia:

Indicates fungal infection:

Malnutrition:

The skin functions to:*Protect us against infection.... as long as the skin is intact,

bacteria cannot enter through the skin

*Protect us from dehydration.... the epidermis is waterproof, so our insides stay moist, as they should.

*Regulate our body temperature.... the subcutanous fat insulates us, sweat glands help to cool our body through evaporation, and blood vessels under the skin constrict to conserve heat. The arrector pili muscles also produce a small amount of heat when the make our hair stand up.

*Collect sensory information...... thanks to all the nerve endings in the skin detecting anything from the slightest touch, to the deepest pressure, sharp pain, heat, and cold.

Beyond pigmentation.... what your color says about you. Pallor - a term for pale skin, lips, or nail beds. Pallor can be caused by cold, anemia, loss of blood, or illness.

Flushing - the skin turns red, typically the face and neck. This can indicate fever.

Cyanosis - a bluish discoloration of the skin, lips, mucosa, or nail beds can indicate poor oxygenation.

jaundice - a yellos color of the skin, eyes, and mucosa can indicate liver disease or a condition that is causing destruction of blood cells (such as sickle cell anemia).

Carotenemia - a yellow or orange discoloration of the skin caused by excessive intake of orange vegetables such as carrots.

A lesion is a wond or damage to the skin tissue. There are many different types.

On Page 85 of "The Human Body in Health and Disease", begin reading about skin lesions, and define the following types.

1. Rash2. Macule3. Papule4. Vesicle5. Pustule6. Excoriation7. Laceration8. Ulcer9. Fissure

Try to identify the types of lesions pictured on the next slide.

A

B

C

D EF

In your book, READ pages 86 - 89

Answer the following questions.

1. What are the two layers of skin?2. Describe the structure of the dermis.4. What is the function of the skin's subcutaneous layer?5. Describe the function of the two major types of skin glands.6. Explain the four important functions of the skin. (listing them only will not get you credit)7. What determines your skin and hair color?8. What protein makes up hair and nails?9. What is involved in the proper care of the skin?10. What is the difference between dermatosis and dermatitis?11. What changes occur in the skin as it ages?12. What causes dermatitis?13. What is the danger of overexposure to the sun?14. Name the most common forms of skin cancer.15. What are the most common causes of baldness?16. What are some things a person's hair and nails can tell you about their overall health?17. What should you do to prevent and control athlete's foot?18. Define: Pruritis, urticaria, psoriasis, and atopic dermatitis.19. What is a decubitus ulcer,and what should we do to prevent it?

Please turn your answers in when you complete them.

I will check and return them to you to use for study purposes.