Ch 7- Skin And Its Appendages Flashcards
Integumentary system
Is the skin. 1.6 to 1.9 square meters
Epidermis
Outer, thinner layer. Epithelial tissue.
Dermis
Inner, thicker layer. Dense, vascular connective tissue.
Subcutaneous layer
Deepest layer. Rich in fat and areolar tissue.
Keratinocytes
Filled with the protein keratin.
Melanocytes
Contribute to skin color. Filter uv light. Produce melanin. (Brown pigment)
Stratum corneum
Horny layer. Outermost layer of the epidermis. Water repellent because of the keratin. Barrier to outside forces and bacteria.
Stratum germinativum
Is stratum basale and stratum spin odium together. Basale is single layer of cells. Mitosis goes on here and new cells gradually move out. Spinosum is prickly layer (many layers of cells) and these cells are still actively making keratin.
Blisters
Form when …injury to epidermal cells
Separation of the dermal- epidermal junction, bonds that hold layers together are weakened, fluid leaks into the space.
Calluses
Form when…abrasions increase the rate of mitosis. A thick stratum corneum results in an area of repeated friction.
Dermis
Thicker than the epidermis, “true skin” provides mechanical strength of the skin.
Papillary layer
Thin with ridges for epidermal attachment. Where ridges are well defined we get finger prints.
Reticular layer
Is the thicker layer of the dermis with network of elastic fibers. Muscle attachment, skeletal and smooth “goose bumps”.
Basal cell carcinoma
Most common form of skin cancer
Squamous cell carcinoma
Second common type of skin cancer not likely to spread.
Malignant melanoma
5% diagnosed, 20% mortality
Most deadly. Develops from mole-like lesion.
ABC rules for melanoma
A- asymmetry
B- border
C- color
D- diameter
Skin color is determined by….
Quantity of melanin produced by melanocytes. Melanin is a brown pigment. Heredity. Also pigment carotene.
Functions of the skin. ESSAY!!!!
PROTECTION: forms a barrier to pathogens, injury, chemicals, melanin protects from sun’s radiation, keeps us from drying out.
SENSATION: sensory receptors for pain, pressure, temp., vibration, and touch.
FLEXIBILITY: movement without injury. Skin is elastic and grows.
EXCRETION: sweat helps us cool. Some wastes found in sweat.
VIT D PRODUCTION.
IMMUNITY: wbc’s cruise in the dermis looking for bacteria.
Heat production comes from….
- metabolism of food
- mostly in muscles and liver
- exercise produces more heat
Body heat lost through….
Evaporation as water evaporates.
High humidity slows evaporation.
Hypothalamus
Thermostat in the brain
1st degree burn
Partial thickness burn. Sunburn, reddening of the skin, minimal tissue damage.
2nd degree burn
Partial thickness burn. Deep epidermal layers and some injury to dermis. Blisters, pain, swelling, edema, may cause scaring.
3rd degree burn
Full thickness burn. Epidermis and dermis destroyed. No pain at first. Scar tissue replaces normal tissue. Very dangerous and serious.
4th degree burn
Involve damage to underlying tissues like muscle, fascia, and bone as well as all layers of skin. You can see exposed bones with this burn.
The biggest risks from serious burns are….
Water/electrolyte loss
Shock
Infection
Eccrine gland
Produce sweat
Cool the body
Originate in subcutaneous tissue
Apocrine gland
Connected to hair follicles Larger than eccrine glands Begin functioning at puberty Smell is bacteria contamination Armpit, breasts, anus
Sebaceous glands
Secrete sebum
Anti-fungal
Accumulation of this oil causes black heads
Ceruminous glands
Secrete cerulean
Ear wax
Only found in ear canals
Impetigo
Bacteria causes reddish discoloration, followed by blisters . Highly contagious.
Times
Fungal infection. Causes redness, itching and scaling.
Warts
Papilloma virus causes rumors which are usually benign.
Boils
Staph infections (bacteria) of hair follicles.
Decubitus ulcers
Bedsores. Pressure sores. Difficulty healing and infection likely due to poor blood flow.
Hives
Urticaria. Raised, red lesions. Caused by allergic reactions, chemicals, or systemic diseases.
Psoriasis
Chronic inflammation disorder. May have genetic basis. Scaly lesions and inflammation.
Scleroderma
Autoimmune disease. Affects blood vessels and connective tissues of the skin, skin hardening, can become systemic.
Eczema
Most common inflammatory skin disorder. Bumps, blisters, and crusts.
Heat stroke
More severe and possibly fatal.
Homeostasis has failed.
Body temp rising. Temp over 105.
Rapid heart rate, headache, dry skin, convulsions, coma, death, replace fluids, cool off now!!
Heat exhaustion
Large amount of water loss.
Disrupts homeostasis but is still trying. Dizzy, weak, nausea, cramps, rest and drink lots of water.
Keratin
Tough, fibrous protein substance in nails, hair, outer skin cells, and horny tissues.
Melanin
Brown pigment primarily in skin and hair.
