Skin Anatomy and Physiology PDF

**Membranes:** - - - - - - - - *Pleura* - lines the thoracic wall and lungs *Pericardium* - encloses the heart *Peritoneum* - lines the abdominopelvic cavity and organs - - - - - - - - - **Skin:** - Protection - Prevents dehydration - Regulate...

**Membranes:** - - - - - - - - *Pleura* - lines the thoracic wall and lungs *Pericardium* - encloses the heart *Peritoneum* - lines the abdominopelvic cavity and organs - - - - - - - - - **Skin:** - Protection - Prevents dehydration - Regulates body temperature - Contains sensory receptors - Synthesizes and excretes substances - - *Draw a picture of the skin. Include all layers.* *Is the subcutaneous layer part of the skin?* --------------------------------------------- \*\*\*The epidermis is made of epithelium, so this layer of the skin does not have a blood supply. -------------------------------------------------------------------------------------------------- *Where does the blood supply for the epidermis come from?* ---------------------------------------------------------- - **Keratinocytes** - most epidermal cells are keratinocytes. They produce the protein keratin. The thickness of the epidermis varies from one region of the body to another. The thickest area on the body is on the palms of the hands and the soles of the feet. - **Melanocytes** - specialized cells in the deepest part of the epidermis (*stratum basale*) that produce the dark pigment **melanin**. Melanin absorbs light energy, protecting the cells of the body from UV (ultraviolet) sunlight. The melanin is transferred from melanocytes to keratinocytes, where it accumulates to form a shield from the UV radiation in sunlight. - **Merkel cells & Meissner's corpuscles**- sensory receptors for touch - **Langerhans cells**- macrophages - - - - - [\ **Dermis**] - strong flexible connective tissue, the "hide" [Subcutaneous layer (Hypodermis):] ---------------------------------------------- Chemicals and drugs can be delivered to the body (through the skin) in a number of ways: Skin color is due to three pigments: - - - Excess sun exposure can cause a number of problems: - leathery skin - elastin fibers clump - immune system depression - skin cancer -- UV radiation alters the DNA of skin cells **[Homeostatic Imbalances:]** - - - - - - **Accessory Organs of the Skin:** - - - - Function: Protection and warmth Male sex hormones (androgens) stimulate hair growth. **Skin Cancer:** - *Is tanning good for you? Why or why not?* Burns: ====== - - - - - - - - - - - -