Ch.4 - Skin and Body Membranes

epithelial membrane

group of membrane tissues that includes mucous, serous, and the cutaneous membranes

cutaneous membrane

dry membrane with 2 layers: epidermis and dermis a.k.a. skin

mucous membrane

membrane lining all body cavities open to exterior, like lungs and digestive tract; adapted for absorption or secretion

serous membrane

lime body cavities closed to exterior , occur in pairs and covers internal organs

lamina propria

loose connective tissue membrane a mucous membrane lies on

parietal layer

outer layer of a serous membrane that lines cavity wall

visceral layer

inner layer of a serous membrane that clings and covers the outside of organs

pleura

the layers of serous membranes covering the lungs

pericardium

serous membrane encasing the heart

peritoneum

serous membranes lining ventral body cavity

serous fluid

thin clear fluid that is found between the visceral and parietal layers of a serous membrane

synovial membranes

connective tissue membranes that line fibrous capsules surrounding joints and help lubricate

skin

self-healing, waterproof, elatic membrane that protects, regulates, and senses outside conditions; a.k.a cutaneous membrane

integument

means "covering", refers to skin and its system

cornified

tough nature of upper layer of the skin due to keratin; hardened

vitamin D

modified cholesterol molecules in skin are converted into this under sunlight

cutaneous sensory receptors

tiny nerves in skin that feel touch, pressure, temperature, and pain

epidermis

most superficial layer of skin that is capable of keratinizing; made of stratified squamous epithelium

keratinize

to become hard and tough with the presence of a certain protein

dermis

dense connective tissue layer of skin firmly connected to epidermis

hypodermis

adipose tissue found deep to the dermis layer of skin; anchors skin to underlying organs, insulates body

strata

layers

stratum germinativum

deepest cell layer of epidermis constantly going under cell division, contains stem cells; aka stratum basale

keratinocytes

cells which produce protein keratin that makes skin tough

stratum spinosum

layer where cells appear prickly or spiny from desmosomes between them, secrete lipids that help waterproof the skin, keratinization begins here

stratum granulosum

granule layer, layer where cells lose their nuclei

stratum lucidum

layer that only occurs where skin is thick and hairless, like soles and palms, cells essentially die

stratum corneum

outermost and thickest epidermal layer, made of cornified dead cell remnants

melanin

pigment that is responsible for skin color and ability to tan, ranges in color from yellow to brown to black

melanocytes

special cells that produce melanin in cells

freckles, moles

these occur when melanin is concentrated in one spot on skin