integumentary system test

epidermis

outer layer of skin; serves as primary barrier between body and environment

stratum corneum

top layer of epidermis

stratum lucidum

2-3 cell layers, below corneum

stratum granulosum

below lucidum

stratum basale

deepest layer, separated from dermis by basement membrane, below granulosum

melanocyte

responsible for skin and hair pigmentation, produces melanin

keratinocyte

barrier against environmental damage by heat, UV radiation, water loss, pathogenic bacteria, fungi, parasites, & viruses

keratin

protein in hair, skin, and nails

keratinization

hardening process of epithelial cells

melanin

skin pigmentation

dermis

deepest skin layer, connective tissue

papillary layer

upper dermal region; loose connective tissue, projections

reticular layer

deepest skin layer; dense connective tissue, blood vessels, sweat & oil glands, deep pressure receptors

hair shaft

visible part of hair that sticks out of the skin

hair follicle

surrounds that strand of hair

hair root

where the hair grows from

pore

opening in skin that releases oil and sweat

arrector pilli muscle

tiny muscle connected to each hair follicle and skin, responsible for goosebumps - raises hair

sebaceous gland

produces oil at hair follicle

sweat gland

produces sweat (water & salts) for temp regulation, dissipates heat & acidic to inhibit bacteria

dermal papillae

protection from dermis that have pain/touch receptors

hypodermis

bottom layer of skin, connects dermis to muscles and bones, insulates your body, fat tissue is found

cancer

abnormal cell mass, classified as benign (does not spread) or malignant (moves to other parts of the body)

connection b/t uv index and skin color

areas with higher altitude and closer to the equator will have darker pigmentation

function of darker pigmentation

sun exposure harms folate, melanin increases folate production - needed for reproduction

function of lighter pigmentation

in areas where melanin is not necessary for protection, vitamin D is prioritized and lighter skin thrives

basal cell carcinoma

least malignant, most common, arises from stratum basale

squamous cell carcinoma

spreads to lymph nodes, early removal = better chance of cure, sun-induced, arises from stratum spinosum

malignant melanoma

most deadly, cancer of melanocytes, spreads to lymph nodes & blood vessels

dermatologist

ppl who study/treat hair, skin, nail conditions

oncologist

ppl who specialize in cancer

first degree burn

only epidermis is damaged, skin is red or swollen

second degree burn

epidermis & upper dermis is damaged, red, blistering

third degree burn

destroys entire skin layer, burn is gray-white or black

benign

doesnt spread

malignant

spreads to other parts of the body

causes of wrinkles

dermis loses collagen/elastin

vestigial structures

structure that is present in an organism but no longer serves its original purpose

why are arrector pilli considered vestigial structures?

we no longer have enough hair to actually warm our body

function of sweat

dissipates heat - as water evaporates, skin surface is cooled

how to the skin and nervous system interact to allow response to stimuli?

cutaneous receptors in the skin detect different stimuli

mechanoreceptors

respond to touch, pressure, vibration, and stretch

thermoreceptors

respond to changes in temperature

nocireceptors

respond to pain