Integumentary System Layers and Functions

1. NOTES – INTEGUMENTARY SYSTEM PART 3

2. Which layer of the Integumentary System is mostly loose connective tissue and adipose tissue? The hypodermis is mostly loose connective tissue and adipose tissue. Which layer of skin is where most cell division occurs? The dermis is the layer of skin where most cell division occurs. What is the top layer of skin called? The top layer of skin is called the epidermis. Which layer of the dermis is the deepest? The deepest layer of the dermis is the reticular layer.

3. Which layer of the dermis is responsible for fingerprints? The papillary layer is the layer of the dermis responsible for fingerprints. Which layer of the epidermis have cells undergone a chemical change and formed layers (sometimes 25 layers thick)? The layer of the epidermis that has undergone a chemical change and formed layers is the stratum corneum or keratinized layer.

4. Which layer of the epidermis is the stratum where most cell division occurs? The layer of the epidermis where most cell division occurs is the stratum basale. Which layer of the epidermis is the stratum where dandruff, calluses, and corns occur? The layer of the epidermis where dandruff, calluses and corns occur is the stratum corneum. What is the pigment called that gives our skin its color? What is the cell that produces this pigment? The pigment that gives our skin its color is melanin and the cell that produces this pigment is a melanocyte.

5. Where is hair produced? Hair is produced by a hair bulb on a papilla in the dermis. What determines hair color? Melanin determines hair color. What causes goosebumps? Arrector pili muscles cause goosebumps. What are the two types of sweat glands? The two types of sweat glands are eccrine and apocrine glands. Where are the sweat glands located? Eccrine are located all over the body while apocrine glands are located in the axillae and genital area.

6. What gland is usually responsible for acne? The sebaceous gland is responsible for acne.

7. Functions of the Integumentary System • Protection • water loss, microbes, foreign objects • Temperature Regulation • maintains homeostasis • Vitamin D Production • used by bones and muscles • Sensation (sense of touch) • sensory nerve receptors in dermis & epidermis • Excretion • small amount of waste, fluid

8. The Effects of Aging on Skin • blood flow to the skin is reduced • skin becomes thinner & more transparent • less elastin & fat causes wrinkles • less collagen – more easily damaged • age spots, discoloration, gray hairs

9. Damage to the Skin: Burns, Cancer, Disease • BURNS • 1st Degree • affects epidermis only

10. 2nd Degree Burn • affects epidermis and part of dermis

11. 3rd Degree Burn • epidermis, dermis, most nerve endings completely destroyed

12. Skin Cancer • BASAL CELL CARCINOMA • most frequent type of skin cancer • begins in stratum basale and goes into dermis • treatment: surgery or radiation • does not metastasize

13. SQUAMOUS CELL CARCINOMA • cells above statum basale • can metastasize & cause death

15. MALIGNANT MELANOMA • from melanocytes in a mole • can metastasize & cause death

16. DISEASES OF THE SKIN • Acne • infection involving hair follicle & sebaceous gland • also can have a significant hormonal cause

17. Viral Infections • caused by a virus • carried to the skin by blood • EX: measles (rubella), chicken pox

18. Warts & Cold Sores • also caused by a virus • relatively harmless, could lead to other conditions