hap unit 5

• overactive sebaceous glands which secretes sebum and causes oily skin

seborrhea

• tearing of dermis resulting from extreme stretching of the skin

• leaves stretch marks

striae

• epidermis is damaged, symptoms are redness, swelling pain

first degree burns

• epidermis and upper dermis affected

• redness, swelling, blisters

• skin regeneration happens with little to no scarring

• 2nd degree burns

• every layer of skin damaged including nerve endings, requires skin grafting for healing

3rd degree burns

• acute trauma, seperates epidermis and dermis

• found on hands and feet

• fluid filled pocket caused by friction

blister

• sebaceous gland sebum trapped in skin surface

whitehead

• sebaceous oil trapped in skin and oxidizes and dries

blackhead

• active inflammation of the pilosebaceous unit

• caused by bacterial infection

acne

• skin structure composed of a hair follicle, sebaceous oil gland, and a small arrector pilli muscle

pilosebaceous unit

• skin layer that acts as protection

epidermis

• skin layer that provides support, mechanical strength, elasticity, and resilience

dermis

• anchor the skin to underlying structures such as skeletal muscles and bones

hypodermis

• deepest epidermal layer, firmly attached to dermis

• cells undergo rapid division

stratum basale

• weblike system of intermediate filaments attached to desmosomes

• tension resisting bundles

• layer is spiny in shape

stratum spinosum

• thin 3-5 cell layers, contains granules involved in keratin formation

• cells begin to die and flatten

• lipids release to form waterproof barrier

stratum granulosum

• thin, clear layer found only in thick skin

• dead flattened cells filled with keratin

• provides extra protection against friction

stratum lucidum

• outermost epidermal layer, made of dead, flattened keratinized cells

• prevents water loss and blocks pathogens

• cells continually shed and are replaced

stratum corneum

• strong protein makes the skin tougher and more protective

keratinized

• white blood cells, macrophages, fibroblasts, mast cells

types of cells in the dermis

• makes 20% of dermis and made of areolar connective tissue, has a lot of collagen and elastic fibers

papillary layer

• wavelike projections on highest surface of papillary layer

• capillary loops, free nerve endings placed in waves to help deliver oxygen and detect pain and temperature

dermal papillae

• 80% of thickness of dermis

• made of dense irregular connective tissue, allowing movement in all directions

reticular layer

• give strength to skin

collagen fibers

• provide stretch and recoil to skin

elastic fibers

• pigment that contributes to skin color

• produced by melanocytes and determines tanning from UV radiation

melanin

• pigment that contributes to skin color

• comes from foods such as carrots and can accumulate in the epidermis and fatty tissues

• contributes to yellow to orangeish skin tones on palms and soles of feet

carotene

• pigment that contributes to skin color

• protein in red blood cells that carries oxygen

• more blood in dermal capillaries = more pink and red

hemoglobin

• most numerous gland throughout body: concentrated in the palms, soles and forehead

• secretory unit in dermis which releases sweat on epidermis surface

eccrine gland

• secretes sweat in genit@ls and armpits

• sweat includes lipids and proteins

• activates at puberty

aprocrine gland

• 99% water, 1% salt vitamin C, antibodies, dermacadin

sweat

• external ear canal

• secrete cerumen (earwax) to help protect ear from foreign objects

ceruminous

• only women, secrete milk after mom has baby

mammary

• damages epidermal barrier upon contact

• once it reaches blood can lead to brain damage or kidney failure

organic solvent or heavy metal exposure

• dermis traps blood and it leaks into surrounding tissues

bruise

• most common form of cancer, stratum basal cells grow into dermis and hypodermis

• extremely slow growth

basal cell carcinoma

• stratum spinosum keratinocytes grow deeper into dermis

• grows extremely fast

squamous cell carcinoma

• effects melanocytes, get mutated and grows fast

• chemo resistant, poor survival rate if dark patch gets above 4mm thick

melanoma

• detects deep pressure and high frequency vibrations in deeper skin layers

pacinian corpusle

• detects light touch and low frequency

meissner’s corpusle

• contracts to pull hair upright to trap heat or signal fear (goosebumps)

arrector pilli muscle

• transmit touch, temperature, pressure, pain from skin to brain

sensory nerve fibers

• produces sweat to cool body down

eccrine sweat gland

• supply nutrients and oxygen while expanding or contracting to regulate body temperature

cutaneous vessels

• help detect light touch in epidermis

merkel cells

• help fight infection w immune system in epidermis

langerhans cells