PHS Ch 9 A&P: Integumentary System

PHS Ch 9 A&P: Integumentary System

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The Integumentary System

Includes skin, hair, and nails

Three layers of skin

• Epidermis

• Dermis

• Hypodermis

Functions of the skin

• Protects and supports the bones, muscles, and internal organs

• Works with other systems to sense touch and maintain body temperature

• Plays a role in producing and storing some nutrients and getting rid of body waste

The Epidermis

• Thin outer layer of skin

• Made up of mostly dead skin cells

• Protects the body from bacteria and holds in moisture to prevent dehydration

• Contains melanin, or pigment

The Dermis

• Second layer of skin

• Made of connective tissue

• Contains most of the skin’s structures: Nerve endings, Blood vessels, Hair follicles, Sebaceous glands, & Sudoriforous glands

• Hair and nails grow from living roots located here

• Fingerprints are formed by this layer

Multiple Choice

What type of finger print do you have?

• Whorl

• Arch

• Loop

The Hypodermis

• Innermost layer of skin, located beneath the dermis

• Contains connective tissue that attaches the skin to the muscle below

• Made mostly of subcutaneous fat, which has some important functions: Provides padding, Holds in body heat, & Stores energy and nutrients

• Some fat is necessary, but excess fat is linked to diseases such as diabetes, heart disease, and cancer

Skin Diseases and Conditions

• Skin cancer Malignant melanoma (most deadly) Basal cell carcinoma (most common)

• Warts: small lumps that often develop on the skin of the hands and feet.

• Dandruff: dry scalp that flakes off

• Acne: hair follicles become plugged with oil and dead skin cells.

• Boil: A painful, pus-filled bump under the skin caused by infected, inflamed hair follicles.

• Skin lesions: an abnormal growth or appearance compared to the skin around it.

Skin Injuries

• Abrasions to the epidermis heal without scarring; lacerations that cut into deeper layers leave a scar

• Pressure ulcers (caused by lack

  of circulation to the skin; bedsores)

• Burns (heat, electricity, chemicals) First-, second-, third-, and fourth-degree, & Rule of nines

• Plastic surgery Cosmetic: enhances beauty Reconstructive: repairs damage

  
  

Now time to practice what you've learned.......

Ted Talk time. pay attention, there will be questions to answer.

Multiple Choice

We rely on ______ to give us our sense of touch.

• The skin’s enormous surface area

• The sensitive hairs on the surface of our skin

• Merkel cells and nerve cells

Multiple Choice

The integumentary system is made up of ______.

• The hair, skin, nails, certain glands, and nerves

• The skin

• Everything you see on the surface of your body

Multiple Choice

The skin’s three layers are ______.

• The dermis, epidermis, and hypodermis

• The dermis, epidermis, and the Langerhans layer

• The dermis, epidermis, and keratin

Multiple Choice

About ______ of the body’s blood supply is circulating through the dermis at any given time.

• 15%

• 17%

• 25%

Multiple Choice

Your skin is your body’s largest organ.

• true

• false

Open Ended

Some people have diseases that disrupt the normal functioning of the skin. Can you imagine life without skin that does its job properly? What sorts of challenges would we face?