4 Did You Know?...At 8-10 pounds, the skin is bodies largest organ!
5 The EpidermisThe epidermis is the outer layer of skin. The thickness of the epidermis varies in different types of skin. It is the thinnest on the ______ at .05 mm and the thickest on ______ at 1.5 mm.Cells of the epidermis are constantly sloughing off and replacing themselves…
6 The Epidermis cont… 5 layers Cells are shaped like columns at the base and migrate upward, as dead cells are continuously sloughed off at the surfacestratum corneumstratum licidumstratum granulosumstratum spinosumstratum basale
8 Specialized Epidermal Cells The melanocyte- produces pigment (melanin)The Langerhans' cell- frontline defense of the immune system in the skin
9 They aid in grasping objects, scratching, and protecting fingers and toes.
10 The DermisThis layer varies in thickness as well, depending on the area of the body. It is a mere 0.3 mm on the eyelid and 3.0 mm on your back.The dermis is composed of 3 types of tissue….
11 The Dermis cont…2 types of tissue that are present throughout (not in layers).collagenelastic tissue
12 Dermis Tissue: Collagen Collagen is the most abundant and important structural protein in your body. It strengthens and supports many body tissues from the outside creating an “extracellular matrix.”
13 Dermis: Elastic tissue Elastic protein fibers made by cells called fibroblasts provide protection for tissues underneath the dermis as well as the pliability we associate with the skin.
14 Specialized Dermal Cells erector pili muscle cells support hair follicles.oil (sebaceous) glands, scent glands, and sweat glands are associated with the follicle.Blood vessels and nerves course through this layer. The nerves transmit sensations of pain, pressure itch, and temperature, and blood vessels facilitate gas exchange.
15 The Importance of Glands Sweat glands play an important role in keeping the body coolsebaceous glands secrete sebum which has waterproof and antimicrobial properties
19 Layer 3: The Subcutaneous Also referred to as the “hypodermis,” this layer of the skin is composed primarily of adipose tissue (fat). This layer plays a key role in insulating the body and regulating the temperature of the skin.The hypodermis can vary significantly in thickness and incorporates larger blood vessels and nerves.
23 Did you Know?Your fingernails grow about 5 times faster than your toenails!
24 HairAlso composed of the protein keratin hair acts as an effective insulator between you and the environment.hair follicles originate in the dermis.
25 Did You Know?Hair can grow as little as 0.1 inches per month or as fast as 0.5 inches per month depending on genetics and your diet.
26 Aging and the integumentary system Marked declines in:Cell division in stratum basaleMelanocyte productionGlandular activityHair follicle functionElastic fiber function in dermisBlood supply to skinRate of repair
27 Disorders of the skin Lesions and tumors infections (bacterial, viral, fungal, parasitic)inflammatory reactions and allergiesGenetic diseasesacne