SKIN (INTEGUMENT, CUTIS)

Function: forms the external covering of the body. It is the largest organ of the body, constituting the 15 - 20% of its total mass

• Barrier function that protects against physical, chemical, and biologic agents in the external environment
• Homeostatic function that helps preserve the constancy of the internal environment by regulating body temperature and water loss
• Sensory function that brings information about the external environment to the individual and, thus, is both informative and protective
• Function in converting precursor molecules into vitamin D
• Excretory function via the sweat glands

1. Skin

• Epidermis
• Cells of epidermis
• Dermis

2. Hair

• Hair follicle
• Hair

3. Sebaceous glands

4. Sweat glands

• Eccrine sweat glands
• Apocrine sweat glands

5. Nails