Chapter 5: Integumentary System Flashcards
describe the layers of the epidermis and the cells that compose them.
Epidermis keratinized squamous epihelium.
The types of cells in the epidermis are keratinocytes, melanocytes, intraepidermal macrophages ,and tactile epithelial cells.
Come Let’s Get Sun Burned !
Superficial to Deep:
1) Stratum Corneum - waterproofs 3/4 epidermis HORNY thickening = callus
2) Stratum Lucidum (ONLY IN THICK SKIN) Clear
3) Stratum Granolsum GRANUAL cytoplasm flattened
4) Stratum Spinosum PRICKLY keratonycytes, melanin and dendrite cells
5) Startum Basale BASAL one row of mitotic stem cells
compare the composition of the papillary and reticular regions of the dermis.
The dermis is composed of dense irregular connective tissue containing collagen and elastic fibers. It is divided into papillary and reticular regions.
The papillary region contains thin collagen and fine elastic fibers, dermal papillae, and corpuscles of touch.
The reticular region contains bundles of thick collagen and some coarse elastic fibers, fibroblasts and macrophages, adipose tissue, hair follicles, nerves, sebaceous (oil) glands, and sudoriferous (sweat) glands.
explain the basis for different skin colours.
1) Melanin
Red Yellow, Brown and Black,
Melanin protects cells from UV rays, and Sunlight encourages melanin growth. Only in deep epidermis because lysosomes break down in superficial layer.
2) Carotene
Yellow to orange in food
3) Hemoglobin
pinkish/blue hue
contrast the structure, distribution, and functions of hair, skin glands, and nails.
1) Hair:
Consists of a shaft, root and follicle, Each hair follicle has a sebaceous gland an arrector pili muscle and a hair root plexus. New hair develops from division of hairmatrix in the bulb occurs in a cyclical pattern of growth, regression and resting. Limited protection from heat loss, sun, entry of foreign particles into the nose and ears
2) Skin Glands
Sebaceous or Oil Glands
Usually connected to hair follicles absent from palms of hand and soles of feet, produce sebum moistens hair and waterproofs skin.
Sudoriferous or sweat glands
Eccrine have extensive distribution, ducts terminate at pores at the surface of the epidermis involved in thermoregulation and waste removal stimulated during emotional stress
Apocrine sweat glands stimulated during emotional stress and sexual excitement. Ceruminous Glands
Modified sudoriferous glands that secrete cerumen (auditory canal)
3) Nails
Dead keratinized epidermal cells over the dorsal surface of the distal portions of the digits. Nail body, free edge, nail root, lunula, hyponychium, nail bed, eponychium and nail matrix. Cell division of the nail matrix produces new nails
compare structural and functional differences in thin and thick skin.
Thin skin covers all parts of the body except for the palms, palmar surfaces of the digits, and the soles (lower epidermis - stratum G, S, B)
Thick skin covers the palms, palmar surfaces of the digits, and soles *stratum lucidum - CLEAR
describe how the skin contributes to the regulation of body temperature, storage of blood, protection, sensation, excretion and absorption, and the synthesis of vitamin D.
Temp - The skin participates in thermoregulation by liberating sweat at its surface and by adjusting the flow of blood in the dermis
Blood reservoir - 81-10 % blood volume
Protection - Keratin, Lipids, oil, Acidic pH, melanin, marcrophages
Sensation - cutaneous layer Cutaneous sensations touch pressure, vibration, tickling, hot, cold,
Tactile discs epdiremis
Corposcules of touch / nerve endings in dermis
Vit D - UV activates skin, and produces calcitriol from enzyme in liver and kidneys
