Integumentary System

light-skinned races such as Caucasians

have approximately the same number of melanocytes as races with darker skins

cause of albinism

an inherited mutant gene for melanin

caused by an abrasion of the skin

a portal entry for microorganisms

determines the color of skin

amount of melanin produced by melanocytes in the skin

2 glands that produce sweat

apocrine and merocrine

region of the body where apocrine sweat glands are most numerous

axilla (armpit) and groin

a dietary substance that can contribute to the color of skin

carotene

the melanocytes in very dark skin

contain single, large, pigment granules

surrounds the nail and provides a barrier against infection

cuticle

the structure in hair that contains hard keratin

cuticle

may result in cold weather from reduced blood circulation through the skin

cyanosis, lack of oxygen in skin tissues

have greater melanin production

dark-skinned people

ways the skin promotes loss of excess body heat

dilation of dermal blood vessels, activation of eccrine sweat glands to release more sweat to skin surface, radiation, conduction, and convection

body heat is conserved

due to the contraction of smooth muscle in the walls of dermal blood vessels

will help cool the body

evaporation of sweat from the skin's surface

causes the skin to darken by stimulating the production of melanin

exposure to ultraviolet light

3 things that influence melanin production

genetics, exposure to sunlight, and pregnancy

grows for a period of time and then rests and grows again

hair

skin discoloration most likely to suggest physical trauma

hematoma

3 non-dietary substances that can contribute to the color of skin

hemoglobin, collagen, and melanin

skin color is the result of

heredity or genetic factors

glands that do not produce sweat

holocrine

a change that does not occur in aging skin

increased collagen

cause of "age spots"

increased melanocytes in certain areas of hands and face

3 changes that occur in aging skin

loss of elasticity, increased likelihood of skin infections, loss of fat from the hypodermis

same number in light-skinned and dark-skinned people

melanocytes

glands most responsible for cooling the skin

merocrine (aka eccrine) glands

skin discoloration most likely to result from anemia

pallor

most active growing region of the nail

nail matrix

modified structures derived from the stratum corneum

nails

protect the ends of fingers and toes

nails

nail technicians should not do this

pull back the cuticles aka eponychium

primary means by which body heat is lost

radiation

Eccrine sweat glands

respond primarily to elevated body temperature

is not a skin gland

salivary gland

associated with the hair follicle, aka holocrine glands, secretion is called sebum

sebaceous glands

types of skin glands

sebaceous, ceruminous, mammary

how eccrine sweat glands differ from sebaceous glands

secretion type, location in the body, sebaceous glands are associated with hair follicles, wheras sweat glands are not

skin change usually associated with aging

skin becomes wrinkled due to decrease in the number of elastin fibers

by reducing body temperature during hot weather

skin helps to maintain body homeostasis...

the activity of apocrine sweat glands

sometimes leads to body odor

produce the nail plate

specialized epithelial cells

layer of epidermis consisting of a single row of columar cells that undergo mitosis and includes pigment-producing melanocytes

stratum basale (germinativum)

the layer of epidermis that has no nuclei in its cells; flat, keratinized, dead cells

stratum corneum

the most superficial layer of the epidermis

stratum corneum

causes elderly persons to become less able to maintain stable body temperatures

sweat glands are replaced by fibrous tissue and their activity decreases as people age...

caused by an increase in body temperature

sweating

do not affect skin color

the quantity of melanocytes or amount of blood in the body

3 groups of people more likely to get skin cancer as they age

those frequently overexposed to the sun, fair-skinned blonds and redheads, and those who have a pre-existing mole

causes stretch marks

torn collagen fibers

contained in sweat

water, salts, and wastes

the hair shaft is pulled perpendicular to the skin surface, and movement of the hair follicle causes "goose bumps"

when the arrector pili muscle contracts

hair color resulting from a decrease in melanin

white

a decrease in the thickness of their subcutaneous fat layer

with aging, causes people to feel colder and usually need a higher temperature, especially in the winter