HAP 5 (complete)

primary function for the epidermis

protect the body from th elements, wind, and uv

serves as barrier to viruses and bacteria

primary function for the dermis

contains blood vessels, lymph nodes, hair follicle, sweat glands, nerve endings

supply the epidermis with oxygen and nutrients

primary function for hypodermis

contains fat; insulate the body; provide protective padding around organs

vitamin D

keeps bones healthy and keeps immune system functioning

keratinocytes

contain the structural protien keratin

provides strength, flexability, and toughness

life cycle of keratinocytes

new cells are at the bottom of the epidermis and migrate to the top while increasing keratin production. when they reach the top they de and lose their necleus and organelles

melanocytes

produce melanin

shaped like nerve cells with long projections to deliver melanin (melanosomes) to keratinocytes

types of melanin

pheomelanin; reddish-yellow pigment appearing pink in color

eumelanin; brown and black varieties appearing brown in color

uvA & uvB

uv B is only 5% of all uv light that reaches earths surface while uvA is the other 95%

the integumentary system is useful for a lot of things like:

protection and touch

vitamin production

temperature regulation

to release heat, blood vessels…

dialate

to retain heat, blood vessels

constrict

keratinocytes

90% of epidermal cells

produce keratin that healp the epidermis protect its self from abrasion and remain waterproof

Langerhans (dendritic) cells

ingest forieng substances and activate immune system

melanocytes

spider shaped cells at the bottom of the epidermis

produce melanin that protects keratinocytes from uv

merkel (tactile) cells

light touch receptors at the epidermis-dermis junction attached to nerve endings

stratum corneum

superficial layer

20-30 laters of dead cells constantly falling off

stratum lucidium

translucent layer of dead cells

onlyn found in thick skin like palm and the souls of feet

stratum granulosum

3-5 layers of keratinocytes

cells flatten, deteriorate, and fill with keratin granules

stratum spinosum

shiny layer of langerhans and keratinocytes

stratum basale

deepest layer of melanocytes and merkle cells

rapid mitosisto push new cells upward

accessory organs

glands, hair, nails, ect

sudoriferous glands

sweat glands in the palms, soles, and forehead

clear and watery

apocrine glands

sweat glands in the armpits and genital area

fatty rich in protein

oderless until broken down by bacteria

modified/specialized glands

ceruminous - in the ear, they produce earwax

mammary - in chest, they make milk

sebaceous glands

produce sebum

white heads

sebum and head cells clog a pore

blackheads

clogged pore opens to the skin surface

pimples

rupture of clogged pore causing localized bacterial inflammation

functions of hair

protection from uv

foreign particles entering body

insulation

hair follicles

located in the dermis

enclosed hair is the root

exposed hair is the shaft

cuticle

outer layer of hair, a single layer that overlaps

keeps hairs aprt and from matting

cortex

middle layer containing flatten cells and melanin pigment

deculla

innermost core containing soft keratin & air spaces

round shaft

straight hair

flat shaft

curly/kinky hair

oval shaft

wavy hair

growth stage

the hair cells divid quickly, and hair gets longer

rest stage

hair is released and falls out

follicle is inactive for 3 months

what do nails do?

they reinforce and protect the distal ends of fingers and toes

nail plate

hard translucent part of nail that protects the nail bed

cells are filled with keratin

nail bed

underneath the nail plate that contains blood vessles, nerves, and melanocytes

nail matrix

produces new growth

growth is continuous

lunula

thick area that may appear as a whight crestent

cuticle

thin layer of dead skin that forms a protective seal at the base of nails

regeneration

repair of destroyed tissue with the same king of cells

(shallow)

fibrosis

replacement of destroyed tissues with dense connective tissue

forms a scar

(deep)

inflammation

the initial responce of the body to injury

limits the extent of injury and initiates repair and regen

redness symptom

vasodilation of blood vessels increases blood flow to the area

heat symptom

increase blood accumulation leands to increased metabolic activity

swelling symptom

inrease permeability of blood vessels allows fluid to enter tissues space

pain symptom

results from injury to neurons an increased pressure from edema

burn

tissues damage and cell death cauased heat, electricity, uv radiation, or chemicals

first degree burn

only epidermis is damaged

skin is red and swollen

second degree burn

epidermis and upper dermis are damaged

skin is red and blistering

third degree burn

destroys entire skin layer, including hypodermis

blood vessels and nerve endings are destroyed

burn is grey/black

skin grafting is neccessery

critical burn

over 25% of the body has second degree burns

over 10% of the body has third degree burns

third degree burns on face, hands, and feet

rules of nines

way to estimate the extent of burns

body is divided into 11 areas for quick estimate

most common types of cancer

Benign & malignant

basal cell carcinoma

least malignant

most common

arisis from cells in stratum basale

squamous cell carcinoma

may metastasize to lymph nodes

early removal allows a good chance of cure

malignant melanoma

most deadly

cancer of melanocytes

metastasizes rapidly to lymph and blood vessles

ABDCE rule for melanoma

Asymmetry - two sides do not match

Border irregularity- borders are not smooth

Color - different colors

Diameter - Larger than 6mm

Evolving - changes size, shape, color, etc