INTEGUMENTARY 2 Flashcards
whats the papillary layer made of
areolar connective tissue
Loose interlacing of elastin and collagen
what does the loose interlacing of elastin and collagen allow for
phagocytes to move freely
how are dermal papillae made
Superior surface indents into the epidermis
what does the papillary layer house
capillaries, nerve endings, and touch receptors
what do dermal ridges contribute to
Enhance friction for grip
Sweat pores on ridge peaks responsible for fingerprints
what does dermis layer provide
supporting strength + withstands tension
whats melanin
skin color that shields from UV light and has two forms (reddish yellow to brownish black)
how does sun exposure relate to DNA damage and melanin
Sun exposure → DNA damage
» ↑DNA repair → ↑melanin synthesis (tanning)
what three things does excessive sun exposure cause
lumping of elastic fibers (leathery skin), depressed immune system and altered DNA of skin cells (i.e. skin cancer)
whats carotene
yellow/orange pigment found in plant products; tends to accumulate in stratum corneum and in fatty tissue of hypodermis
what does hemoglobin cause
causes pinkish hue of fair skin
what are eccrine / merocrine glands
everywhere; abundant in palms, soles of feet, and forehead
what are apocrine / merocrine glands
found in axillary and genital areas
what does sweat from apocrine glands contain
fatty substances and proteins » Gives yellowish color
what results in body odor
Bacteria in apocrine sweat decompose substances → body odor
describe sweat in 4 ways (whats it made of, acidity, what it kills, 2 things it contains)
99% water
Acidic (pH 4 – 6)
Dermcidin (kills bacteria)
Contains some salts and wastes
what are sebaceous glands and where are they found
“Oil glands”
Found everywhere except palms and soles
Small on trunk and limbs; large on face, neck, upper chest
what are holocrine glands
type of sebaceous glands that secrete sebum into hair follicle
what does sebum do
Softens skin and hair
» Slows water loss
» Bactericidal
how is sebum presented
cell erupts, so sebum + cell fragments are present
what are the functions of skin
Protection
» Body temperature regulation
» Cutaneous sensation
» Metabolic function
» Blood reservoir
» Excretion
what are three types of chem barrier
Acid mantle, Dermcidin, Melanin
describe acid mantle
low pH secretions hinder bacterial growth
describe dermcidin
in sweat; kills bacteria
describe melanin
UV radiation
what are two physical barriers
Stratum corneum, Water resistance
describe stratum cornea
multiple layers of closely packed, dead, flat cells
describe water resistance
glycolipids surrounding cells
describe biological barriers
Dendritic cells engulf foreign substances
» Present to immune cells to trigger immune response
Dermal macrophages handle viruses and bacteria that penetrate epidermis
describe hot temperature regulation
Cutaneous blood vessel vasodilation
Sweat (evaporation)
describe cold temp regulation
Cutaneous blood vessel vasoconstriction
describe the excretion function of skin
Sweat: limited amounts of nitrogen-containing wastes ammonia, uric acid)
describe the blood resvoier function of skin
Hold up to 5% of blood volume
what does skin do to collagenase
synthesize it
what does skin do to steroid hormones
activate
what does skin do to cholesterol molecules
to vitamin D precursors from sunlight (which is why we need 10-15 min sunlight a day)
extra question weird song???
wear sunscreen
