Integumentary System Galena Park High School A&P Instructor: Terry E. Jones

A. Protects deeper tissues from: 1. Mechanical damage - (bumps) 2. Chemical damage - (acids/bases) 3. Bacterial damage Galena Park High School A&P I. Function

4. Ultraviolet radiation - (damaging effects of sunlight) 5. Thermal (heat or cold) damage 6. Desiccation (drying out) Galena Park High School A&P

B.Aids in body heat loss or heat retention (controlled by the nervous system) C.Aids in excretion of urea and uric acid D. Synthesizes vitamin D Galena Park High School A&P

A. Epidermis Layer (5 sub-layers) 1. Has no vascular tissue 2. Gets nourishment by diffusion 3. Most cells are filled with keratin fibers – makes the skin tough Galena Park High School A&P II. Anatomy

4. Deepest layer is the stratum basale a. Produce millions of cells that push upward b. Also called stratum germinativum Galena Park High School A&P

5. As cells move upward, they become filled with keratin 6. Next layer –stratum spinosum 7. Followed by the stratum granulosum Galena Park High School A&P

8. Next layer is clear – stratum lucidum. Found only on palms and soles of feet. 9. Outer layer is the stratum corneum. Galena Park High School A&P

10. Outer layer dead cells. Our skin is new every days. 11. Melanocytes are found in the basale layer and produce melanin. Basale cells engulf melanin to protect DNA from UV rays. Galena Park High School A&P

B. Dermis Layer (2 sub-layers) 1. Underlies the epidermis. 2. Top Layer- papillary layer a. Uneven with finger like projections into the epidermis b. Have capillaries to nourish the lower epidermis Galena Park High School A&P

c. Projections on fingers form the fingerprints for gripping things d. Some projections are touch and pain sensors. Galena Park High School A&P

e. Lots of tough collagen fibers f. Phagocytes cruise around eating bacteria that get through the epidermis Galena Park High School A&P

C. Skin Appendages 1. Sebaceous oil glands a. Ducts empty oil into hair follicle b. Oil kills bacteria and keeps hair from getting brittle Galena Park High School A&P

2. Exocrine Sweat Glands a. Ducts sweat into pores b. Sweat contains water, salts, vitamin C, ammonia, uric acid and lactic acid that attracts mosquitos Galena Park High School A&P

3. Apocrine Sweat Glands a. Develop at puberty in axillary and genital regions b. Sweat contains fats and proteins that bacteria love – body odor made by bacteria Galena Park High School A&P

4. Hair and Hair Follicles a. Follicle-end in the skin b. Shaft – what we see c. Basale cells push upward forcing the dead cells out which now are mostly keratin Galena Park High School A&P

d. Each hair has a tiny muscle that moves it called the arrector pili e. The little muscles cause goose bumps when its cold Galena Park High School A&P

5. Nails a. Cells push outward from the basale layer and become keratinized b. Nail grows from the matrix end (little white crescent) c. Most of the nail are dead cells turned to keratin Galena Park High School A&P

A. Infections and Allergies 1. Athlete’s Foot- fungus disease 2. Boils and Carbuncles a. Neck area b. Caused by bacteria infection Galena Park High School A&P III. Homeostasis

3. Cold Sores –caused by a virus infecting mouth area and lips 4. Contact Dermatitis –caused by exposure to a chemical such as poison ivy 5. Impetigo-Bacterial infection causing watery blisters on skin Galena Park High School A&P

6. Psoriasis – dry, scaly skin for which the cause is not known. May be genetic or stress related. Galena Park High School A&P

B.Burns 1. Causes –Cell Death a. Intense heat b. UV radiation – sunburn c. Electrical d. Chemicals- Acids Galena Park High School A&P

2. First Degree Burn a. Involves the epidermis only b. Causes redness c. Recovery occurs Galena Park High School A&P

3. Second Degree Burn a. Involves the epidermis and part of the dermis b. Redness and blistering c. Recovery is good, usually no scarring Galena Park High School A&P

4. Third Degree Burn a. The dermis layer is completely dead b. Whitish or black, tissue exposed c. Recovery long and serious, only a skin graft can replace the dead skin Galena Park High School A&P

C. Cancer 1. Basale Cell Carcinoma a. Least malignant b. Slow growing c. 99 % curable Galena Park High School A&P

2. Squamous Cell Carcinoma a. Occurs in the stratum spinosum b. Major cause is UV exposure c. Can metastasize d. Successfully treated if caught early Galena Park High School A&P

3. Malignant Melanoma a. Occurs in the melanocytes b. About 5 % of Skin cancers c. Can metastasize d. 50 % survival rate with treatment Galena Park High School A&P