bio 230 - skin and body membranes

keratinocytes

most common cell found in the epidermis

sebaceous glands

produce sebum that prevents excessive dryness and keeps skin soft and pliable

eccrine/merocrine

sweat glands that are found in most parts of skin and participate in thermoregulation

skin response to overheating

sweat is produced, blood vessels of dermis dilate

melanin

pigment mostly responsible for skin color

keratin

cells of epidermis that waterproof the skin and protect against abrasion

apocrine

sweat glands associated with hair follicles and most found in armpits and groin, produce odorous sweat

stratified squamous epithelial tissue

top layer of skin, epidermis

stratum lucidum

waxy translucent layer of epidermis only found in thick skin on palms and soles

third degree burn

full thickness burn that affects the entire epidermis and dermis

stratified squamous epithelial tissue is the layer that

can heal and regenerate most quickly

place red blood cell in hypertonic solution

cell shrivels or crenates

place red blood cell in hypotonic solution

cell absorbs water and bursts

place red blood cell in isotonic solution

cell shape goes unchanged

cutaneous and serous

two main types of covering and lining membranes

cutaneous membrane

covers outside of body

mucous membrane

lines cavities open to the exterior

serous membrane

lines organs and body cavities, secretes serous fluid to reduce friction

protect from damage, synthesize vitamin d

functions of integumentary system

epidermis and dermis

two main divisions of the integument

the epidermis is avascular

epidermis does not have a blood supply

stratum basale, spinosum, granulosum, lucidum, corneum

layers of epidermis from deepest to superficial

stratum corneum

stratified squamous epithelial tissue composes the

melanocytes

spider shaped cells that produce melanin

merkel cells

touch receptors in the epidermis

free nerve endings

most common nerve endings in skin, extend into middle of epidermis, sensitive

pacinian corpuscles/lamellar corpuscles

detect pressure and high frequency vibrations

dermal papillae and papillary layer of dermis

responsible for fingerprints

has only penetrated epidermis

paper cut that does not bleed

ceruminous glands

produce ear wax

cold sores

occur around lips, caused by herpes which localizes in a cutaneous nerve

contact dermatitis

irritated/allergic response of skin that can lead to acute or chronic inflammation

psoriasis

red patches on epidermis, chronic condition, immune system attacks person’s own tissue, rapid overproduction of skin cells