Membranes Epithelial membrane- combination of epithelial layer and underlying connective tissue

Mucous Membrane (Mucosae) Line cavities that open to exterior (i.e. GI tract) Connective tissue layer called lamina propria Secretes mucous

Serous Membrane Also known as serosa Lines body cavity not open to exterior (pleura, pericardium, peritoneum)- parietal and visceral Secrete serous fluid

Cutaneous Membrane The skin

Synovial Membrane Line joint cavities Do not contain epithelium Secrete synovial fluid

Integumentary System Cutaneous membrane Largest organ 16% body weight 2 square meters area The Skin

4 types of cells Keratinocytes: 90% Langerhans cells Merkel cells produce keratin and lamellar granules Langerhans cells mount immune response Merkel cells contact sensory neurons Melanocytes: 8% produce pigments to absorb UV radiation

produce new keratinocytes/ tonofilaments for attachment Stratum basale: produce new keratinocytes/ tonofilaments for attachment

Stratum spinosum: tonofilaments for strength and stability

Stratum granulosum: flattened dying cells- release keratin and lamellar granules

Stratum lacidum: only in thick layers flattened dead cells

Stratum corneum: flattened, dead, continually shed

Skin Graft

Psoriasis

Dermis

Striae: Tears in Dermis (stretch marks)

Epidermal Ridges

Tanning Skin colors Freckles Melanin Moles

Vitiligo Albinism

McCune Albright Syndrome Link

Tattooing Currently there are two men who are nearly tied for the Most Tattoo Man record. One is a retired military man who lives in Scotland named Tom Leppard, who just happens to have 99.9% of his body covered in leopard spots. He has no other tattoo designs other than this all-covering pattern which is only absent from the insides of his ears and between his toes.

Elaine Davidson of Edinburgh, Scotland, has acquired a record 462 body piercings since January 1997, 192 of which are on her head.

Hair anatomy

lanugo vellus terminal hair

Sebaceous gland- secretes oil to coat hair and skin Sudoriferous glands- secrete sweat Eccrine- throughout skin- regulate temp/ eliminate some Waste Apocrine- armpits, groin, breast, face- stimulated with stress

Ceruminus Gland (earwax)

Nails Tightly packed, hard, dead, keratinized epidermal cells

sensations protection absorption blood reservoir thermoregulation

Figure 1. Acute wound healing in porcine skin at 3 days (upper left panel), 5 days (upper right panel),7 days (lower left panel) and 10 days (lower right panel). An organized fibrin clot is observed at 3 days, but there is no evidence of new dermal tissue healing. In contrast, at 5 days connective tissue cells (fibroblasts) and blood vessels have filled the defect. Reorgan- zation of the tissue has occurred over the next week (days 7 and 10).

Ecoderm (epidermis) Mesoderm (dermis)

Aging Mostly dermis- loss of collagen, elasticity of fibers decreases, decreased immune response, less oil and sweat, less melanocytes, skin thins