Integumentary week 1

Largest organ

skin

Skin receives how much cardiac output?

1/3

Skin is made up of what percentage of water

15-25%

Skin renews itself every

28 days

thinnest skin

eyelids

thickest skin

palms and soles

Most dust in house is

dead skin

How long does a nail take to grow

6 months

How many strands of hair loss per day

50-100

One square inch of skin contains

0 19 million cells

0 20 blood vessels (8 feet)

0 78 yards of nerves

0 1,300 nerve endings

0 20k sensory cells

0 65 hairs

0 650 sweat glands

Sweat doesn't smell

bacteria does

Epidermis thickness

0.06-0.6mm

Dermis thickness

2-4 mm

Is the epidermis vascular

No, it is avascular

what tissue lies under the dermis

Subcutaneous fatty tissue (hypodermis)

Hair follicles start in the

dermis

How long does it take a cell to travel from the basal layer to the stratum corneum

15-30 days

keratinocytes form in the

basal layer

keratinocytes are important for

healing

Thickest layer of epidermis

stratum corneum

3/4 of epidermis is

stratum corneum

stratum corneum

the most superficial layer of the epidermis consisting of dead cells

is the stratum corneum waterproof?

No, it is water resistant but not waterproof

stratum corneum permits

slow loss of water by insensible perspiration

Stratum lucidum

a layer of the epidermis found only in the thick skin of the fingers, palms, and soles

Stratum lucidum is

Clear, transparent layer of skin

stratum granulosum

3rd layer of the epidermis

keratinocytes produce

kertohyalin and kertin in the granulosum

keratin fibers devleop as

cell becomes thinner and flatter

water resistant barrier is made where

Stratum Granulosum

Stratum Spinosum

spiny layer

Stratum Spinosum contains

langerhans and melanocytes

langerhans cells

epidermal macrophages that help activate the immune system

melanocytes

cells that produce melanin

stratum basale

the deepest layer of the epidermis consisting of stem cells capable of undergoing cell division to form new cells

stratum basale attaches to

basal lamina

merkel cells are located in

stratum basale

where are keratinocytes born

stratum basale

keratin provides

waterproof covering

Number of melanocytes similar

Various skin colors

Size & activity of melanocytes differ and give

skin it's colors

freckles are

Concentrated groups of melanin

Cells of the epidermis

stem cells, keratinocytes, melanocytes, tactile cells, dendritic cells

Melanocytes protect from

UV radiation

Merkel cells

touch receptors in the skin

Epidermal appendages

hair, sebaceous glands, sweat glands, nails

Roles of the epidermis

Vitamin D production, regulates fluid, physical/chemical barrier, appearance, waste disposal

If a cut doesn't bleed

it's only in the epidermis

Epidermis thermoregulation

0 Hairs provide thermal covers and sweat glands cool skin

Epidermis and vitamin D

0 Makes vitamin D when exposed to sunlight

0 Critical for bone formation and calcium absorption from intestinal tract

Dermis layers

papillary and reticular

Basement membrane of the dermis

Attaches dermis to stratum Basale

dermis is

vascular

Dermis can withstand

large pressure

What provides the epidermis with nutrients

vasculature from the dermis

Dermis cell types

fibroblasts, macrophages, and occasionally mast cells and white blood cells

fibroblasts provide skin what

toughness and stretchability

Mast cells

Cells that release chemicals (such as histamine) that promote inflammation.

the dermis should look

shiny, moist and pink

Can the dermis regenerate?

no

1 multiple choice option

large scars can't

sweat

functions of the dermis

thermoregulation, sensory reception, supports epidermis, nourishes epidermis

blisters occur from

friction between the dermis and epidermis

adipose tissue

0 Insulation and cushioning

0 Energy source

0 Can store Vitamins A, D, E ,K

0 Highly vascular

0 May be dark if dehydrated

0 Yellow if healthy

superficial wounds

involve only the epidermal layer of the skin

superficial wound examples

abrasions and 1st degree burns

partial thickness wound

Involves the epidermis and the dermis but does not extend through the dermis to the subcutaneous layer

partial thickness examples

Superficial and deep partial thickness Blister

2nd degree burn

Stage 2 pressure injury

Wagner grade 1 ulcer

Granulation occurs in

partial thickness wounds

full thickness wound

the dermis, epidermis, and subcutaneous tissue are penetrated; muscle and bone may be involved

full thickness examples

Full stage thickness burn

Stage 3 pressure injury

Subdermal (4th degree burn)

Wagner grade 1-5 ulcers

full thickness wound

partial thickness wound

superficial wound

Phases of wound healing

inflammatory, proliferative, maturation

Inflammatory stage purpose

Control bleeding and fight germs and bacteria

inflammatory stage length

3-6 days

Vascular response

increase blood flow to site of an injury

cellular response

adaptation at the cellular level that involves a cell responding to signals in its environment

PNMs

polymorphonuclear leukocytes

Fibroblasts produce

all 3 types of fibers (collagen, reticular, elastic fibers) through synthesis and secretion of protein subunits that combine or aggregate within the matrix

Vasodilation occurs when

vascular smooth muscle tissue relaxes to increase the diameter of the lumen

exudate

fluid that accumulates in a wound; may contain serum, cellular debris, bacteria, and white blood cells

transudate

The fluid component of blood that normally passes through the endothelial cell walls of the microcirculation

histamine

short term vasodilation

Prostaglandin

long-term vasodilation

Signs of inflammation

redness, heat, swelling, pain, loss of function

proliferation stage purpose

Growth and production of cells to produce tissues required to close wound

length of proliferation stage

Can start 48 hrs after injury but may start days after

Health of wound determines how long it lasts and when it starts

events in proliferation

angiogensis, granulation formation, wund contraction, epithelialization

Angiogenesis

formation of new blood vessels

Granulation formation

Temporary lattice of vascularized connective tissue that allows for contraction and epithelialization across the wound

granulation is replaced by

scar tissue

wound contraction

process whereby the borders of a wound are physically drawn together

Amount of contraction affected

by shape & depth

what wounds heal the slowest

circular

which wounds heal the fastest

straight

Deeper wounds contract more

than partial thickness wounds

wounds heal from

bottom up, sides in

epithelialization

stage of wound healing in which epithelial cells form across the surface of a wound; tissue color ranges from the color of "ground glass" to pink