Sponge: Set up Cornell Notes on pg. 57

Topic: Ch. 6 Integumentary System: Life-span changes and skin cancer

Essential Question:

1. What changes occur in the epidermis and dermis with age?

2. What is the most common type of skin cancer? Who is most likely to develop this cancer?

2.1 Atoms, Ions, and Molecules

1. What changes occur in the epidermis and dermis with age?

2. What is the most common type of skin cancer? Who is most likely to develop this cancer?

6.7 Life-Span Changes and Skin Cancer

2

Skin Cancer• Cancer begins when ultra violet radiation mutates the

DNA of a skin cell• Usually arises from non-pigmented epithelial cells within

the deep layer of the epidermis OR from pigmented melanocytes

• Epithelial cells= carcinomas

3

• Cutaneous carcinomas are skin cancers originating from the epithelial cells• Most common type of skin cancer• Occur most freq. in light-skinned people over 40 yrs• Usually appear in people who are regularly exposed to

sunlight

2 types:• Basal cell carcinoma• Squamous cell carcinoma

4

• Cutaneous Melanomas arise from the melanocytes• Seems to be caused by short, intermittent exposure to

high-intensity sunlight• Appear most often in the skin of the trunk, back, and

on limbs

5

Life Span Changes• Age spots appear

• Wrinkling & sagging• Epidermis thins• Dermis shrinks• Loss of fat

•Sebaceous glands secrete less oil

• Dry skin

• Skin becomes scaly

• More elastic

• Fewer lymphocytes delay wound healing

6

• Melanin production slows• Gray or white hair

• Hair thins and slower growth• Number of hair follicles decrease

• Nail growth becomes impaired• Dull and harden

• Sensory receptors decline

• Body temperature unable to be controlled

• # of sweat glands decrease• # of blood vessels decrease• Ability to shiver declines

• Cannot tolerate cold or regulate heat