2. Integumentary System

3. Membranes 1.Serous 2.Mucous 3.Synovial 4.Cutaneous

4. Serous Membranes Serve as inner linings Secrete a watery serous fluid

5. Mucous Membranes Line cavities and tubes that open to the outside Secrete mucus

6. Synovial Membranes Line joint cavities Secrete a thick colorless synovial fluid.

7. Cutaneous Membrane “skin”

8. Skin and its Tissues Two distinct layers –Epidermis –Dermis

9. Epidermis Stratified squamous epithelium Lacks blood vessels Older outer level cells are keratinized.

10. Most important function is to protect the body Contains specialized cells, melanocytes –Produce melanin: produces skin color, absorbs light

11. Dermis Binds the epidermis to the underlying tissues Contains blood vessels, nerve fibers, hair follicles, sebaceous glands, sweat glands.

12. Subcutaneous Layer “hypodermis” Contains adipose tissue to insulate Contains the major blood vessels that supply the skin

13. Accessory Organs of the Skin Hair follicle –Root –Shaft –Errector pili muscle

14. Sebaceous glands –sebum

15. Nails –Nail root –Lunula –Nail bed

16. Sweat glands –Exocrine –Pore –Apocrine glands

17. Regulating Temperature Sweat, as the liquid evaporates the surface is cooled Vasodilation, allows heat to leave the vessels Vasoconstriction…

18. Healing wounds Inflammation, the result of fluids being forced out of vessels and into damaged tissues –This provides a wealth of nutrients. Scab (152-153) Scar granulation