Chapter 6 Flashcards
The skin and it’s accessory structures( hair, nails, glands, sensory receptors) make up?
Integumentary system (cutaneous membrane)
Skin consists of two layers
Epidermis outer
Dermis inner
Outer layer of skin; composed of simple squamous epithelium with basement membrane between epidemic and dermis
Epidermis
Inner layer of skin, thicker than epidermis. Connective tissue, with collagenous and elastic fibers, blood muscle, nervous tissue
Dermis
Layer beneath dermis, insulating layer. Comprised of areolar and adipose tissue, not part of skin contains blood vessels that supply skin
Subcutaneous layer
(hypodermis)
Cell of epidermis found in stratum spinosum, phagocytes- protect skin and underlying tissue from infection
Dendritic (langerhans) cells
Skin cell found in stratum basale, along with sensory nerve endings, for Tactile Discs in dermis, act as sensory receptors for light touch
Tactile (Merkel) cells
Skin cells found in stratum basale, produce the pigment of melanin. Absorbs uv light from sunlight and provides skin color. Protects against DNA damage, fibroblast damage, and skin cancer
Melanocytes
Two layers of the dermis
Papillary layer
Reticular layer
Superficial layer of dermis, areolar connective tissue, thinner of the two layer. Location of dermal papillae, which forms finger prints
Papillary layer
Deeper layer of dermis, dense irregular connective tissue, thicker of the two layers
Reticular layer
Accessory structures of the skin consist of
Hair follicles
Nails
Skin glands (sweat and sebaceous)
Protective covering of ends of fingers and toes
Nails
Parts of nail
Nail plate(body)
Nail bed
Nail matrix
Lunula
Cuticle
Tube-like depression of epidermal cells from which hair develops; extends into dermis and or the subcutaneous layer
Hair follicle
Extends from skin surface to dermis or hypodermic (hair)
Hair root
Deepest part of hair root; contains diving cells of hair matrix
Hair bulb
Portion of hair that extends beyond skin surface; composed of dead, epidermal cells
Hair shaft
Contains blood vessels to nourish hair
Hair papilla
Attached to hair follicle; contracts in response to cold or fear; and causes goose bumps
Arrector pili muscle
Holocrine gland that is usually associated with hair follicles, produces sebum; keeps hair and skin soft and waterproof, excess sebum can cause acne
Sebaceous glands
Glands that are widespread in skin, originate in deeper dermis or hypodermis as ball-shape coils
Sweat (sudoriferous) glands
Three types of sweat glands
Eccrine (merocrine) glands
Apocrine sweat glands
Specialized sweat glands
Most numerous glands in skin, consists mainly of water some salts, wastes. Responds to elevated body temp and open to body surface through pores
Eccrine (merocrine) glands
Axillary and groin areas; open into hair follicles. Response to emotions and pain
Apocrine sweat glands
Two types of specialized sweat glands
Ceruminous glands
Mammary glands
Ear wax and a produced by
Ceruminous glands
Breast milk is produced by
Mammary glands
Functions of the skin
Protective barrier
Sensation
Excretion
Vitamin D (starts in skin)
Regulate body temperature
Four ways heat is lost through the skin
Radiation
Conduction
Convection
Evaporation
Primary method, infrared heat rays travel from warmer skin to cooler environment
Radiation
Heat moves from warmer skin to cooler object
Conduction
Heat loss from skin into circulating air currents
Convention
Heat is lost through sweat as it evaporates, and carries heat away from the skin
Evaporation
Thermoreceptors signal hypothalamus, validation of dermal blood vessels, vasoconstriction of deep blood vessels, sweat glands activated when…
Body temp rises
Thermoreceptors signal hypothalamus, dermal vessels vasoconstrict, deeper blood vessels vasodilate, sweat glands are inactive, muscles contract involuntarily (shiver)
Body temp falls
Abnormally high body temperature. Skin becomes dry, person gets weak, dizzy, nauseous, headache, rapid pulse
Hyperthermia
Abnormally low body temperature. Progresses to confusion, lethargy, loss of reflexes, and consciousness. Without treatment organs shut down
Hypothermia
Normal response to injury or stress, body’s attempt to restrict spread of infection. Skin may become reddened, swollen, warm, painful
Inflammation
Burn where injuries only to epidermis, as in sun burn; rednesss, heat, inflammation
Superficial, partial thickness (first degree) burn
Burn that destroys epidermis and some dermis, as in burns from hot liquid. May blister. Healing varies on burn severity. Stem cells in hair follicles and glands can regenerate skin. Usually recovers completely, no scarring
Deep, partial-thickness (second degree) burn
Destroys epidermis, dermis, accessory structures. Prolonged exposure to heat, flames, hot liquid. Some healing from margin. Often requires skin grafts, skin substitutes
Full-thickness (third degree) burn
