The skin and body membranes Anatomy chapter 6 The skin and body membranes

Purpose of Membranes Covering Line cavities Protective sheets

Two types of membranes according to tissue type epithelial-cutaneous(skin), serous(lines body cavities) and mucous(mouth,lungs) a. Peritoneum-covers organs b. Pleura-covers lungs c. Pericardium-covers heart

2. Connective-synovial that lines joints and secretes fluid

Location terms: Parietal-outside wall covering Visceral-inner wall covering

Integumentary system: Composed of cutaneous(skin), sweat and oil glands, hair and nails

Layers of the integumentary: Epidermis-avascular-can shave without bleeding Dermis-vascular-epidermis and dermis are cemented together-if heat and friction split them apart then a blister forms Subcutaneous

Purpose: Protection Insulation Cushions internal organs

Structures continued: Meissner’s corpuscles-touch receptors with nerve endings Collagen and elastic fibers for strength and flexibility Phagocytes to eat bacteria that has penetrated the epidermis Fingerprints are films of sweat left on a surface

Skin conditions: Redness-blushing, hypertension Jaundice-liver disorder-excess bile in blood that is deposited in the skin Hematomas-bruises-blood leakage and clotting Cyanosis-bluish looking skin-decrease in oxygen-decrease in breathing rate-leads to heart failure

Skin coloring: Keratinizing-skin cells become tough and hard-protein that is water repellent Melanin-yellow, brown, black pigment that gives skin color-natural sun screen Skin color is determined by amount and kind of melanin in the epidermis and amount of carotene from foods we eat Pigment is released by melanocytes in the epidermis Freckles or moles are concentrated melanin