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Giselle Rojas Period 3 Integumentary System - Coggle Diagram
Giselle Rojas Period 3 Integumentary System
MAJOR FUNCTION OF THE SKIN
SKIN FUNCTION
protective covering, prevents many substances and pathogenic microorganisms from entering body
protection of underlying tissue
houses sensory receptors
conducts part of the process for making vitamin D
body temperature regulation, via sweat gland activation, and vasodilation or vasoconstruction of dermal blood vessels
healing of wounds
ROLE OF SKIN IN BODY TEMPERATURE REGULATION
proper temperature regulation is vital to maintaining metabolic reaction rates
the skin plays a major role in temperature regulation, with the hypothalamus controlling the process
heat may be lost to the surroundings from the skin through radiation
HEALING OF WOUNDS
INFLAMMATION: in which blood vessels dilate and become more permeable, causing tissues to become red and swollen, is the body normal response to injury
dilated blood vessels bring in fluids, oxygen, nutrients, and immune cells to aid in healing
CHARACTERISTICS OF INFLAMMATION
REDNESS: vasodilation, more blood in area
HEAT: large amount of blood accumulating in area and as a by-product of increased metabolic activity in tissue
SWEALLING: increased permeability of blood vessels, fluids leaving blood go into tissue spaces (edema)
PAIN: injury to neurons and increased pressure from edema
THE HEALING OF A DEEP WOUND
The response to a deep injury, extending into the dermis or subcutaneous layer:
involves the formation of a blood clot from the released blood
the blood clot and dried tissue fluids form a scab to cover the wound
extensive collagen fiber production in the area may for an elevated area called a scar
LAYERS OF THE SKIN
2 LAYERS : EPIDERMIS & DERMIS
EPIDERMIS: thin, outer layer of Stratified Squamous epithelium
DERMIS: thicker, inner layer of Connective tissue, blood vessels, smooth muscle, and nervous tissue
A Basement Membrane separates epidermis from dermis & anchors these layers together
SUBCUTANEOUS LAYER (HYPODERMIS)
layer underneath dermis, consisting of areolar and adipose tissue
binds skin to underlying tissue, but NOT part of the skin
adipose tissue insulates to conserve body heat
contains major blood vessels that supply the skin
binds the epidermis to underlying tissues
genetically determined pattern of friction ridges formed by dermal papillae provide for unique FINGERPRINTS
dermis consists of areolar and dense connective tissue with collagen and elastic fibers within gel like ground substance
fibers provide toughness and elasticity to skin
dermal vessels carry nutrients to upper layers of skin to help regulate body temperature
dermal contains nerve fibers, sensory receptors, hair follicles, sebecous glands, and sweat glands
made up of statified squamous epithelium
lacks blood vessels
consists of 4 layers in most areas, 5 layers in thick skin
STRATUM BASALE (or stratum germinatium)
deepest; consists of dividing cells; well nourished by dermal blood vessels
As basal cells divide, older cells called KERATINOCYTES due to accumulation of fibrous protein, keratin, migrate toward skin surface
4 LAYERS (Stratum Lucidum, Stratum Basale, Stratum Spinosum, Stratum Granulosm, Stratum Corneum)
Stratum Lucidum (layer between stratum granulusm & stratum corneum only found in thick skin of palms and soles
Stratum Basale: innermost layer, dividing layer
Stratum Corneum: outermost layer, dead, flattened, keratinized cells; are continously being shed from outter skin surface
MELANOCYTES
produces the pigment melanin
Location: deepest layer of epidermis and dermis
Melanin protects DNA of skin cells against damaging effects of UV radiation from fun
Melanin pigment provides skin/hair color, the more melanin, the darker hair/skin
SKIN COLOR
All people have about same # of melanocytes
skin color is genetically determined, involves amount of melanin that melonocytes produce
exposure to sunlight, UV light, and x-rays cause darkening skin due to increase in melanin production
SKIN COLOR (2)
circulation within dermal blood vessels affect the skin color
well-oxygenated blood has a pinkish color, due to hemoglobin
poorly oxygenated blood looks blue, due to deep red tone of the hemoglobin, called cyanosis
yellowish skin color can come from eating too many orange foods with carotene, or from jaundice due to liver disease
ACCESSORY ORGANS (HAIR, NAILS, GLANDS)
NAILS
protective coverings over the ends of fingers and toes
consists of a nail plate overlying a layer of skin surface, called the nail bed
LUNULA: half-moon shaped structure at base of nail plate, most actively growing region of the nail root
as new cells are produced, older ones are pushed outward and become KERATINIZED, just as in other parts of skin
HAIR FOLLICLES
hair can be found in all regions of skin EXCEPT palms, soles, lips, nipples, and portions of external genitalia
each hair develops from epithelial stem cells at the base of a tube-like depression called HAIR FOLLICLE
hair follicles dip down into the dermis or sometimes the subcutaneous layer
the deepest part of the HAIR ROOT is called the HAIR BULB, it is located at the base of the hair follicle
as new cells are formed in the bulb, old cells are pushed outward and become keratinized, and die forming the HAIR SHAFT
hair is COMPOSED of dead, keratinized epithelial cells
HAIR COLOR AND PROPERTIES
hair color is determined by genetics
melanin produced by melanocytes is responsible for most hair colors, type and amount are factors
genetic lack of melanin causes albinism (white)
a bundle of smooth muscle cells, called ARRECTOR PILI MUSCLE, attaches to each hair follicle; when it contracts, in response to cold temperature or emotional upset, it causes GOOSE BUMPS
GLANDS
SEBACEOUS GLANDS: holocrine glands; entire cells filled with secretion are released
associated with hair follicles
secrete an oily substance called SEBUM (oil), that waterproofs and moisturizes the hair shafts the skin
SWEAT (SUDORIFEROUS) GLANDS
merocrine glands; secretions exit cells via exocytosis
2 TYPES OF SWEAT GLANDS
1.) ECCRINE: merocrine glands that respond to body temperature; more abundant type; many found in forehead, neck, back
2.) APOCRINE: merocrine glands (incorrectly named) which become active at puberty; respond to fear emotional upset, pain, or sexual arousal; most numerous in axilla and groin; sweat contains proteins and fats that produce body odor
MODIFIED SWEAT GLANDS
CERUMINOUS GLAND: secrete wax in ear canal, to trap dust and pathogens
MAMMARY GLAND: secrete milk to nourish a baby
SKIN CANCER and the ABCDE RULES
skin cancer arises in nonpigmented cells in the deep layer of epidermis or from melanocytes
skin cancers originating from epithelial cells are called cutaneous carcinomas (squamous cell carcinoma and basal cell carcinoma): those arising from melanocytes are cutaneous melanomas (melanocarcinomas or malignant melanomas)
ABCDE RULES
A: asymmetry
B: border (irregular)
C: color (more than one)
D: diameter (more than 6 millimeters)
E: evolution or change
These cancers are caused by short, intermittent exposure to high-intensity sunlight, such as when a person who usually stays indoors occasionally sustains a blistering sunburn
a CUTANEOUS MELANOMA usually appears in the skin on the back or limbs, arising from normal-appearing skin or from a mole(nevus)
surgical removal during the horizontal growth phase arrests the cancer in six of every seven cases
once the lesion thickens and deepens, it becomes difficult to treat and the survival rate is low
UVA & UVB types of ultraviolet radiation, can cause the mutations that trigger skin cancer
RULE OF NINES
ANTERIOR HEAD & NECK: 4 1/2%
ANTERIOR TRUNK: 18%
ANTERIOR UPPER EXTREMITIES (arms): 4 1/2 each and both front arms together arms are 9%
PERINEUM: 1%
ANTERIOR LOWER EXTREMITIES (legs): 9% each leg and both front legs together are 18%
POSTERIOR HEAD & NECK: 4 1/2%
POSTERIOR TRUNK: 18%
POSTERIOR UPPER EXTREMITIES (arms): 4 1/2% each and both back arms together are 9%
POSTERIOR LOWER EXTREMITIES (legs): 9% each leg and both back legs together are 18%
ANTERIOR & POSTERIOR HEAD & NECK: 9%
ANTERIOR & POSTERIOR UPPER EXTEMITIES: 18%
ANTERIOR & POSTERIOR TRUNK: 36%
PERINEUM: 1%
ANTERIOR & POSTERIOR LOWER EXTREMITIES: 36%
ALL TOGETHER: 100%
DEGREES OF BURNS AND THE RULE OF NINES
FIRST DEGREE (superficial partial thickness)
a few hours outside on a sunny summer day w/o sunscreen
slightly burned skin becomes inflamed, warming and reddening (erythema) as dermal blood vessels dilate
few days, the surface layer of skin may peel
only damages the EPIDERMIS , no scarring
SECOND DEGREE (deep partial-thickness)
a burn that destroys some epidermis as well as some underlying dermis
fluid escapes from damaged dermal capillaries, accumulating beneath the outer layer of epidermal cells, forming blisters
injured region becomes moist and firm and may vary from dark red to waxy white
COMMON CAUSES: hot objects, hot liquids, flames, burning clothing
THIRD DEGREE (full-thickness)
a burn that destroys the epidermis, the dermis, and the accessory structures
skin becomes dry and leathery, may vary in color from red to black, to white
results from immersion in hot liquids or prolonged exposure to hot objects, flames, or corrosive chemicals
if injured area is extensive, a transplant may be necessary