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

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.