integumentary Flashcards
-consists of the skin, hair, glands, and nails.
-protects us from the external environment. Other functions include sensation, vitamin D production, temperature regulation, and excretion of small amounts of waste products.
integumentary system
stratified squamous epithelium divided into strata.
epidermis
from deep to superficial are stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum.
strata
produced in the stratum basale.
new cells
consists of many layers of dead squamous cells containing keratin. The most superficial layers are sloughed.
stratum corneum
the transformation of stratum basale cells into stratum corneum cells.
Keratinization
results from keratin inside the cells and from desmosomes, which hold the cells together.
structural strength
surrounding the stratum corneum cells help prevent fluid loss.
lipids
dense connective tissue.
dermis
provide structural strength, and the blood vessels of the papillae supply the epidermis with nutrients.
collagen and elastic fibers
produce melanin, which is responsible for different skin colors.
melanocytes
production is determined genetically but can be modified by exposure to ultraviolet light and by hormones.
melanin
a plant pigment ingested as a source of vitamin A, can cause the skin to appear yellowish.
carotene
produces a red skin color, whereas decreased blood flow causes a pale skin color.
increased blood flow
results in the blue skin color of cyanosis.
Decreased blood O
collagen produces a bluish color.
scattering of light
which is not part of the skin, is loose connective tissue that attaches the skin to underlying tissues. About half of the body’s lipids are stored.
subcutaneous tissue
-columns of dead, keratinized epithelial cells. Each hair consists of a shaft (above the skin), a root (below the skin), and a hair bulb (site of hair cell formation).”
-have a growth phase and a resting phase.
hairs
which are smooth muscles, causes hair to “stand on end” and produces a “goose bump.”
contraction of the arrector pili
produce sebum, which oils the hair and the surface of the skin.
sebaceous glands
produce sweat, which cools the body.
eccrine sweat glands
produce an organic secretion that causes body odor when broken down by bacteria.
apocrine sweat glands
consists of the nail body and the nail root.
nail
produces the nail, which is composed of stratum corneum cells containing hard keratin.
nail matrix
-reduces water loss, prevents the entry of microorganisms, and provides protection against abrasion and ultraviolet light; hair and nails also perform protective functions.
-contains sensory receptors for pain, heat, cold, and pressure.
skin
stimulates the production of a precursor molecule in the skin that is modified by the liver and kidneys into vitamin D
ultraviolet light
increases calcium uptake in the small intestine.
vitamin D
-Through dilation and constriction of blood vessels, the skin controls heat loss from the body.
-Evaporation of sweat cools the body.
temperature regulation
Skin glands remove small amounts of waste products but are not important in excretion.
excretion
easily observed and often reflects events occurring in other parts of the body (e.g., cyanosis, jaundice, rashes).
integumentary system
damage only the epidermis (first-degree burn) or the epidermis and the dermis (second-degree burn).
partial thickness burns
(third-degree burns) destroy the epidermis, the dermis, and usually underlying tissues.
full thickness burns
damage tissue deeper than the subcutaneous tissue, including muscle and bone.
fourth degree burns
