Skin and Body Membranes

Epithelial membranes

Cutaneous, mucous, serous

Cutaneous

skin, exposed to air

Mucous

lines body cavities exposed to the exterior, wet and moist

Serous

lines body cavities closed to exterior

Parietal layer

outer layer that lines the body wall

Serous fluid

lubricates organs, reduces friction, cushions them

Visceral layer

inner layer that covers the organ itself

Peritoneum

membrane lining the abdominal cavity and the organs inside

Pleura

membrane lining the lungs

Pericardium

membrane lining the heart

Synovial membranes

line fibrous capsules surrounding joints, secrete lubricating fluid, line bursae and tendon sheaths

Function of synovial membrane

cushioning

Bursa

fluid filled sac in joints

Tendon sheath

wraps around a tendon

Joint cavity

spaced in between bones in a synovial joint filled with synovial fluid

Articular cartilage

connective tissue covering bone ends in joints

Main functions of integumentary system

keep substances in, protection from bacteria, nervous system receptors, etc.

Skin

7% total body weight, epidermis, dermis, hypodermis

Epidermis

top layer of skin, avascular, melanin

Dermis

2nd layer of skin, fibroblasts, macrophages, mast cells, WBC, fibers, nerve, blood vessels, lymphatic vessels

Hypodermis

subcutaneous tissue; fat

Stratum Basale

deepest layer of epidermis

Stratum Corneum

outermost layer of epidermis

Papillary

upper layer of dermis, fingerprints

Reticular layer

80% thickness of dermis, collagen, elastin, H2O, flexure lines

Flexure lines

dermal folds near joints

Decubitus ulcers

pressure ulcers

Striae

stretch marks

Blisters

epidermis and dermis separate

Blisters are caused by

friction, heat, chemicals

Arrector pili muscle

contracts to straighten hairs; goose bumps

Melanin

made in skin by melanocytes, yellow→black

Freckles and pigmented moles

local accumulations of melanin

Tans

melanocytes stimulated by the UV rays

Carotene

orange

Cyanosis

blue, not enough oxygen

Erythema

red

Pallor

paleness, lack of sun, sick, exhaustion, scared, blood loss

Jaundice

yellow, cirrhosis; fatty liver

Hematoma

blood tumor

Rubor

red

Hepatitis A

fecal→oral, acute

Hepatitis B

sexual contact, sharing needles, blood contact

Hepatitis C

needle sharing, no vaccine, chronic

Skin appendages

nails, sweat glands, oil glands, hair

Sebaceous glands

excrete sebum, empty into hair follicles, not on palms or soles

Functions of sebaceous glands

keep skin soft, keeps hair from becoming brittle, kill bacteria

Whitehead

pimple; bacteria, oil, dead WBC

Blackhead

oxidized whitehead

Acne

excess oil, clogged pores, genetics, diet, bad hygiene, hormones

Seborrhea (cradle cap)

oil discharge

Sweat glands

eccrine, apocrine

Eccrine

sweat, secreted through pores, prevent overheating

Apocrine

axillary and genital areas, ducts empty into hair follicles, contains sweat plus fat and proteins, milky or yellow color, BO

Ceruminous glands

external ear canal, cerumen; earwax

Mammary glands

secrete milk

Hair functions

sense insects, guard against trauma, heat loss, sunlight, shield eyes, filter large particles

Hair structure

dead, keratinized cells; shaft; root; matrix; cuticle

Shaft

projects from skin

Root

embedded in skin

Matrix

where hair growth happens

Cuticle

outermost layer of cells; strength, split ends

Hair follicles

epidermis to dermis, hair bulb below surface, arrector pili

Vellus hair

thinner, peach fuzz

Terminal hair

continues to grow, thicker

Hair growth

¼ to ½ inches per month, 6 week cycles

Hirsutism

females displaying secondary male sex characteristics, idiopathic

Primary female sex characteristics

development of ovaries and ova

Primary male sex characteristics

descending of testicles and development of sperm

Secondary female sex characteristics

hips widen, breasts develop, fat

Secondary male sex characteristics

deep voices, hair, muscles, bigger and taller

Alopecia

inability to grow hair

Male patter baldness

Hair loss on top of head

Nails

hard keratin, free edge, body, root, nail bed, nail matrix, lunula, cuticle

Anterior and posterior head and neck

9%

Anterior and posterior upper limbs

18%

Anterior and posterior trunk

36%

Perineum

1%

Anterior and posterior lower limbs

36%

1st degree burn

epidermis; redness

2nd degree burn

epidermis and dermis; blisters

3rd degree burn

epidermis and dermis destroyed

Skin grafting

taking skin from another place to regenerate an area; eschar, synthetic skin

4th degree burn

all tissue gone; bone exposed

Histocompatibility

if body will reject new skin or not

Critical burns

over 25% body has 2nd degree burns; over 10% body has 3rd degree burns; 3rd degree burns to hands, feet or face

Athlete’s foot

itchy, dry, red, cracked, redness, tinea pedis; fungus

Boils and carbuncles

staph; bacteria

Cold sores

herpes; virus

Contact dermatitis

allergies

Impetigo

staph; contagious

Psoriasis

autoimmune; HLA-B27

Eczema

idiopathic

Skin cancer

UV radiation, sunburned areas, DNA damage

Basal cell carcinoma

least malignant, most common, sun-exposed areas, surgery

Squamous cell carcinoma

keratinocytes, scaly reddened papule, head and hands, rapid growth and metastasis, surgery and radiation

Melanoma

melanocytes, resistant to chemo

ABCs

Asymmetry, Borders, Color, Diameter, Elevated

Vernix caseosa

head cheese

Milia

whites spots on nose and forehead