Chapter 6: Integumentary System Flashcards
(30 cards)
Dermatology
Scientific Study and medical treatment of the integumentary system
Integumentary system
The body’s outer layer. Made up skin, hair and nails. Skin is most vulnerable organ.
Epidermis
the superficial region that is ABOVE. avascular
Dermis
underlies epidermis, most fibrous connective tissue, vascular
Hypodermis
Superficial fasica that is mostly adipose tissue.
NOT part of skin.
Thick skin
covers front of hands and bottom of feet (palm and souls) (0.5mm) FIVE STRATA
Thin Skin
covers rest of the body (0.1mm) has hair follicles, sebaceous glands and oil glands FOUR STRATA
functions of our skin
protection, body temperature regulation, cutaneous sensation, metabolic functions, blood reservior, excretion of wastes
Three barriers that are protected
Chemical barrier, Physical barrier, Biological barrier
Chemical Barrier
-Skin secretes many chemicals
Defensins
sebum and defensins fills bacteria. chemical barrier secretes antimicrobial defensin
Melanin
provides chemical barrier against UV radiation
Physical Barrier
Flat dead kertinizied cells of stratum corneum, surrounded by glycolipids that block most water and water soluble substances
Biological Barriers
-epidermis contains phagocytic dendritic cells
-DNA can absorb harmful UV radiation, converting it to harmless heat
-dermis contains macrophages
dendritic cells
special type of immune cells that are found in tissues such as skin (boosts immune responses)
thermoregulation
the maintenance of the physiologic core body temperature by balancing heat generation with heat loss
insensible perspiration
under average resting body temperature sweat glands produce 500 ml/ day of UNNOTICEABLE sweat
Sensible perspiration
Body temperature rises and causes dilation of dermal vessels to increase sweat gland activity (NOTICEABLE sweat)
Body in cold temp.
dermal vessels constrict cause skin temp to drop
Cutaneous sensory receptors
-part of the nervous system
-respond to stimuli outside the body, such as temp, touch, and pain
Metabolic functions
-synthesize vitamin D needed for calcium absorption
-keratinocytes can activate some hormones
Cells of epidermis
Keratinocytes
Melanocytes
Dendritic cells
Tactile cells
Keratinocytes
(most abundant)
-Produce fibrous keratin (protien that gives skin its protective properties)
-tightly connected by desmosomes
- most common cells of the epidermis
Melanocytes
-produce pigment melanin
- protects nucleus from UV damage