Anaphy (IS)

• Integumentary system - protects the body from environmental damage
• Dermatology - medical specialty for the diagnosis and treatment of skin disorders
• Skin - largest organ of the body
• three layers of skin - epidermis, dermis, subcutaneous layer
• epidermis - outer layer of the skin, composed of keratinized stratified squamos epithelium
• dermis - connective tissue layer of the skin, composed of collagen and elastin fibers
• sebaceous glands - secrete oil to lubricate the skin and hair
• keratinocytes - produce keratin which is a tough fibrous protein that provides protection
• melanocytes - produce the pigment melanin that protects against damage by ultraviolet radiation
• Langerhans cells - involved in immune responses, arise from red bone marrow
• Merkel cells - function in the sensation of touch along with the adjacent tactile discs
• stratum lucidum - translucent layer lying directly beneath the corneum
• stratum corneum - outermost strata of the epidermis. mostly dead cells, filled with a protein substance called keratin
• corneocytes - dead keratinocytes that are continuously shed and replaced by cells from deeper strata
• Keratinization - the accumulation of more and more protective keratin occurs as cells move from the deepest layer to the surface layer
• dandruff - an excess of keratinized cells shed from the scalp
• stratum germinativum - the innermost layer of the epidermis, and contains melanin… the pigment that gives color to the skin
• Stratum spinosum - 8-10 layers of keratinocytes
• stratum granulosum - which includes keratohyalin and lamellar granules
• Dermis - beneath the epidermis and is composed of connective tissue
• Two layers of dermis - papillary layer and reticular layer
• papillary layer - arranged into microscopic structures that form ridges. These are the finger- and footprints
• reticular layer - beneath the papillary layer; it is a white fibrous tissue that supports the blood vessels
• Epidermal ridges - reflect contours of the underlying dermal papillae and form the basis for fingerprints
• Dermatoglyphics - the study of the pattern of epidermal ridges
• 2 main types of subcutaneous layer - Apocrine sweat glands and Eccrine glands
• Apocrine sweat glands - secrete at hair follicles in groin and anal region as well as armpits.
• Eccrine glands - found in greater numbers on palms, feet, forehead, and upper lip. Important in regulation of temperature
• Sebaceous gland - secretes an oily substance called sebum into hair follicle to lubricate skin and hair
• Sebum - keeps skin from drying out and helps destroy some pathogens on skin's surface
• Three pigments: melanin, carotene, hemoglobin
• melanin - pigment that absorbs light and gives skin its color. Yellow-red or brown-black pigment produced by melanocytes
• Carotene - yellow-orange pigment
• Hemoglobin - red pigment in blood cells
• Albinism - inherited inability to produce melanin
• Vitiligo - loss of melanocytes in the skin, resulting in white patches
• Ceruminous glands - modified sweat glands located in the ear canal
• cerumen- producing a waxy secretion, prevents entry of foreign bodies into the ear canal
• Nail- composed of hard, keratinized epidermal cells located over the dorsal surfaces of the ends of fingers and toes
• cuticle- fold of tissue that covers nail root