Skin Flashcards
What are the 6 functions of the skin
Protection temp. regulation waste elimination (excretion) sensory perception production absorption
How does the skin protect us
keratin
melanin
acidic sweat
water barrier
What is keratin-P
(a protine that adds structural strenghth- is found in the outermost layer of skin, in hair, and in nails) protects agenst physical damage
melanin-P
protects agenst UV ray damage (specialized cells in the skin called melanocytes produce melanin. Everyone has the same number of melanocytes, but based on genes, they produce mor or less, melanin which provides pigment. Ultraviolet light activates the melanocytes to produce more melanin to protect and tan the skin.) frekles are small concentrated areas of pigment.)
Acidic sweat-P
protects agenst bacterial infections
Water barrier- P
keratin and oils (sebum-produced by sebaceous glands) in the skin
Capillaries dilate-TR
(get big)- to release heat and constrict-(get small)-to conserve heat
sweat glands (sudoriferous glands) -TR
secrete sweat which evaporates to provide cooling
excretion-WE
Urea and salts are eliminated in sweat
sensory perception
receptor cells send information about touch, pressure, vibration, pain, and temperature to the central nervous system (brain)
production
sunlight converts cholesterol molecules to vitamin D. This is essential for proper functioning of bones, heart, digestion, and functioning immune systems
Absorption
ability of skin to absorb lotions, medications, etc
What are the 3 layers of the skin
epidermis
dermis
hypodermis or subcutaneous
Epidermis
- 5 epidermal layer
- contain no blood vessels or nerves
- upper layer consists of stratified(layered) squamous (scaly) epithelium
- layered full of keratin
- Gives support and strength to the skin
- shed every 25-45 days
- lower layer (basal layer) is consttantly growing and multiplying
- inner layer absorbs nutrients from dermis
- younger cells push older cells to the surface
Dermis
- top layer is covered with papillae-fit into ridges on the lower portion of the epidermis-forms ridges on skin-unique to everyone
- made of 4 types of tissue
- conective:(collagen) gives skin shape, strength and elasticity
- Nervous: contains nerve endings for sensory perception
- Epithelial: makes up the blood and lymph vesseld, the hair, and the glands-sweat glands (suderiferous)2-3mill-oil glands-sebacous(help keep skin and hair soft. also kills barcteria-hair folicles(living in the folicle). melanocytes produce the pigment of the hair and skin
- Muscle: involantary muscles (arrector pili-cause goosebumps)
Hypodermis or subcutaneous
Hypodermis-connects skin to underlying muscle tissue
-composed of lipocytes(fat cells). these store fat and provides cushioning and insulation. also contains larger blood vessels and larger nerve fibers
Macules
(macular rash) flat spots on skin, such as freckles
Papules
(papular rash) firm, raised areas such as pimples and the eruptions seen in some stages or chickenpox and syphilis
vesicles
blisters, or fluid-filled sacs, such as those seen in chicken pox
pustules
pus-filled sacs such as those seen in acne, or pimples
Crusts
areas of dried pus and blood, commonly called scabs
Wheals
itchy, elevated areas with an irregular shape; hives and insect bites
Ulcer
A deep loss of skin surface that may extend into the dermis; may cause periodic bleeding and the formation of scars
Cyst
a closed sac with a distinct membrane that develops abnormally in a body structure; usually filled with a semisolid material
