Integumentary System

Functions of the integumentary system

-protection (uv rays, chemicals, bacteria)

-sensation (nerve endings)

-temperature regulation

-vitamin d production

-excretion

Epidermis layers (deep to superficial)

stratum basale

stratum spinosum

stratum granulosum

stratum lucidum

stratum corneum

Stratum Basale

-deepest layer of epidermis with the youngest living cells.

-most rapid cell division

Stratum Spinosum

(spiny layer) layer of the epidermis that provides strength and flexibility to the skin; highest mitotic rate

Stratum granulosum

flattened cells; produce keratin that grow hair and nails

Stratum lucidum

clear layer on palms and soles

Stratum corneum

outer layer of the epidermis consisting of a thick layer of dead cells. scalelike, slough off

Dermis Layers

papillary

reticular

Papillary

areolar connective tissue; includes dermal papillae

Reticular

network of collagen and reticular fibers

Keratinocytes

deepest epidermal cells, produce keratin.

Melanocytes

cells that produce melanin in epidermis (dark skin pigment)

Merkel cells

sensory nerve endings in epidermis

Langerhans cells

epidermal macrophages that help activate the immune system

(ex. dendritic cells)

Dermis cells

fibroblasts, macrophages, mast cells, WBCs

Fingerprints

ridges formed by the dermal papillae, in the papillary layuer of the dermis

Where do hair and nails come from?

hard keratin that is formed in the stratum granulosum

Where is the hypodermis located?

below the skin

Hypodermis

fat located under the dermis, helps insulate the body and protect underlying muscles and structures.

Melanin

most important gives skin color

Carotene

yellow-orange pigment from carrots and yellow veggies

Hemoglobin

pink of light skin

Types of hair

vellus: fine, short hairs

intermediate hairs

terminal: longer, courser hair

Functions of hair

protection (scalp)

sense (light touches on skin)

warmth (less in mammals)

Apocrine

creates odor while exiting through hair follicles in the axillary, anal, and genitals; functions as scent glands

Addison's disease

appearance of tan bronzed skin

Contact dermatitis

An inflammation of the skin caused by having contact with a substance

Seborrhea

yellowish scum built up on scalp. scaly dandruff like

Cyanosis

blue discoloration of the skin

Jaundice

yellowing of the skin due to bilirubin build up or liver disorder

Erythema

redness (blushing)

Hematoma

bruise (clotted blood)

Malignant

cancerous

First degree burn

Superficial burn of epidermis resulting in redness (ex.sunburn)

Second degree burn

epidermis and upper dermis are damaged, skin is red with blisters

Third degree burn

full thickness (white,red,black)

Rule of 9's

Calculates percent of body burned for rehydration

Epidermis as a whole

major skin area that produces derivatives (hair/nails)

Bedsore

bony projections go into skin resulting in restriction of blood supply causing tissue death

Sensory receptors in the Dermis

pain, pressure, temperature

Greatest risks for severe burn victims

infection and dehydration

ABCD rule

asymmetry, border irregularity, color, diameter (>6mm)

Eccrine glands

true sweat and exits through pores to regulate body temperature

Benign

not cancerous