Anatomy - integumentary system

What does it consist of

Skin and accessory structures: hair, glands and nails

Functions of skin:

Protection, sensation, vitamin d production, temp regulation and excretion

Three layers:

Epidermis, dermis, hypodermis

Three layers of epidermis layer:

Stratum corneum, intermediate strata, stratum basale

Stratum corneum function

Dead squamous cells with keratin

Intermediate strata function:

Cuboidal cells become squamous

Stratum basale function:

Mitotic division every 19 days

Keratinization

New cells being formed, pushing old cells toward the surface where they become hard, dead cells

Melanin is a …

Pigment

Melanocytes

Cells that produce melanin

Melansomoes

Package melanin and transfer it to the epithelium

Eumelanin

Black/brown pigment

Pheomelanin

Red/yellow pigment

Things that effect skin color:

Blood flow, exposure to uv rays, hormones, genetics

Difference between thick and thin skin

Thick skin has more keratinized cells in the epidermis layer

Dermis contains and usage:

Dense collagenous connective tissue, fingerprints and stretch marks

Thick skin location:

Palm and feet

Hypodermis contains and usage:

Loose connective tissue (adipose), foundation for skin, padding and insulation

Hair follicles structures and roles:

Follicle: extension of dermis
Shaft: above skin, medulla/cortex/cuticle
Bulb: were hair and melanin are produced
Arrector pili: smooth muscle that causes goose bumps

Sebaceous glands function:

Not a sweat gland
Produce and secrete oily substance that is rich in lipids to keep structures hydrated
Lubricates hair and surface of skin using sebum

Eccrine sweat glands functions:

Not tied to hair follicles
Used to cool body - sweat
Most located in palms and feet

Aprocrine sweat glands functions:

Odors
Only founds in armpits and genitals
Become active at puberty
Secrets odorless substance that becomes bo when broken down by bacteria

Cutaneous receptors functions:

Sensory receptors found in the dermis
Sense pain, pressure, and temp.

Types of cutaneous receptors:

Thermoreceptor - senses heat and cold
Meissner’s corpuscle. - senses touch
Nociceptor - senses. Pain
Pacinian corpuscle - senses pressure

Hair shaft vs. hair root

Hair shaft is the top, visible part of the hair and the root is where hair comes out of, not visible.

Parts of the nail:

Body, root, cuticle, matrix, bed, lunula, and free edge

Nail body

Visible part

Nail root

Covered part

Cuticle

Stratum corneum that extends onto nail body

Nail matrix

Produces nail and is the epithelial tissue from stratum basale

Nail bed

Softer part under the nail

Lunula

Visible epithelial tissue (half circle)

Free edge

Top white part of nail

Partial vs. full thickness burns

Partial only burns through some of the skin layers, full burns through all layers.

Partial thickness burns

1st and 2nd degree

Full thickness burns

3rd degree

Physiological changes with full-thickness burns:

Less protection
Decrease in blood volume
Elevated temp and heart rate (hyper metabolic state)
Increased risk of infection

Cyanosis

Cut of blood flow to extremities, blue finger tips

Jaundice

Liver damage - yellow skin

Scarlet fever

Hives all over body

Rickets

Vitamin d deficiency

Iron deficiency anemia

No cuticle

Vitamin a deficiency

Extremely dry skin

1st degree burns:

Only epidermis layer
Redness, pain and swelling
No scaring
Healing time: 1-2 weeks
Caused. By: sunburn or brief exposure to hot and cold surfaces

2nd degree burns

Burns through epidermis and dermis layers
Redness, swelling, pain and blisters
Healing time: 2 weeks - 2 months
Sometimes scares

3rd degree burns

Burns through all layers
Appears all colors
Painless because it burns off pain receptors
Healing time: 1 or more years

Three types of skin cancer

Basal cell carcinoma
Squamous cell carcinoma
Melanoma

Basal cell carcinoma

Caused by uvb rays
Most common type of skin cancer
Starts in status basale and extents into dermis
Presents as open sore ro reddish patch
Treatment: removal or radiaition therapy

Squamous cell carcinoma

Located in the intermediate strata and status corneum
Continues to divide as keratin is produced
Can cause death if spreads into dermis
Caused by uvb rays
Presents as open sore

Melanoma

Caused by uva rays
Most deadly especially if it spreads to dermis
Caused my melanocytes in preexisting mole

ABCDEs

A-asymmetry
B-border irregularity
C-change in color
D-change in diameter (greater than 1/4 inch)
E-evolving

Malignant

Active

Metastasize

Spreading

Benign

Dorment