Integumentary System-pg. 5

Body Membranes- 1) Cutaneous (skin) & Mucosa 2) Serosa 3) Synovial

Body Membranes-Epithelial- Cutaneous (skin) & Mucosa

Epithelial & Connective- Serosa- parietal and visceral

Connective- synovial (joints)

Skin

Skin Function •Protects against: bumps, chemicals, bacteria, sun,

temperature and desiccation•Aids in body heat control•Excretes urea & uric acid•Synthesizes vitamin D

Structure-Epidermis- epithelial tissue up to 5 different type layers

Stratum basale- (bottom)•Closest to the dermis•Well fed keratinocytes•Contains melanocytes

•Produce melanin that shields against sun damage

Stratum spinosum-2nd (bottom)Stratum granulose-3rdStratum lucidum-4thStratum corneum-top 20-30 layers of thick dead cells, filled with keratin

DermisTop region = papillary layer with dermal papillae, push up epidermis = fingerprints

Deeper region = reticular layer

Dermis contains

blood vessels, sweat and oil glands,pressure receptors, (pacinian)rich nerve supply, hair follicles

Hypodermis- subcutaneous, adipose tissue anchors skin

Skin color- everyone has the same number of melanocytes, but some produce more/less melanin

Things that affect skin color:Melanin- yellow, red, brownCarotene- yellow pigmentHemoglobin- rednessCyanosis- blue (lack of O2)Pallor- paleJaundice- yellow, liver problemsBruise- hematoma

Glands in SkinAll exocrine (ducts)Sebaceous- oil, deposit sebum into a duct that opens to a hair follicle or surfaceAcne: Blockage= whitehead -> blackhead -> pimple

SudoriferousSweat glands (2.5 million)

• Eccrine- all over, empty at surface, temperature regulation• Apocrine- axillary and genital

area, form at adolescence, empty into hair follicles, can mix with bacteria = smell• Cerumenous- earwax (cerumen)

Hair• Fastest growing cells living in

the matrix, dead cells in shaft.• Surface arrector pili muscle-

attaches the hair to dermis• Contracted = skin dimples

Nails- living matrix, rest is nonliving bed and free edge

Burns

1st degree- red, swollen, pain- epidermis damaged

2nd degree- red, pain, blister, epidermis & upper dermis

3rd degree- gray, white, black, no pain, entire skin, thick

Problems:

• Infection•Airway obstruction (face)•Scar tissue

• RuleOf Nines• Calculates the% burned

Neoplasms -Abnormal growths--Most are benign (not cancer)

Basal Cell Carcinoma

•From Stratum basale, surgically removed- curable

Squamous Cell Carcinoma• From Stratum spinosum-

grows rapidly, curable

Malignant Melanoma• From melanocytes, can be deadly

•A- asymmetry•B- border irregularity•C- color•D- diameter-> 6mm (eraser)

Other Problems

Infections:• Athlete’s Foot- fungus• Boils bacterial infection• Cold Sores- Herpes S Virus• Contact dermatitis- chemical

(poison ivy)• Impetigo- staphylococcus

Psoriasis- auto immuneStriae- stretch marksFlexure lines- creases over jointsBlister- epidermis and dermis separateLines of Cleavage- tension lines

Development• Fetus-–5-6 months-lanugo (fine, soft

hair)

Birth• Vernix caseosa- cheesy cover• lubricates skin

•Milia- oil glands/white spots

Adolescence-• Oily skin • Oily hair • Acne,• Axillary hair and sweat

Old Age-• Subcutaneous fat decreases• Decreased oil production• Less elastin• Less hair• Less Langerhorn cells (immunity)• Less melanin