SKIN AND BODY MEMBRANES

groups of tissues working together to perform a common function

• Epithelial
• Connective

• Mucous
• Serous
• Synovial
• Cutaneous

Mucous- lines passages that opens to the exterior of body. Ex: squamous, or columnar epithelium

Functions: traps particles; coats olfactory receptors; lubricate foods in mouth; protects lining of stomach & intestine from digestive juice.

Serous- lines closed cavities of the body. Ex: simple squamous epithelium

• Functions: secretes serous fluid for lubriation
• thorax-pleura
• abdominal-peritoneum
• heart-pericardium

Synovial- lines joint cavities. Ex: connective tissues only

• Functions: secretes fluid=synovial fluid- reduces friction at moveable joints
• Also forms fluid filled sacs around joints=bursae-reduces friction of mucles, tendon and legaments moving

• Cutaneous- is the integumentary systems also called the skin.
• The largest organ in our body.
• Covers outer layer and surface of the body.

• considered an organ or an organ system.
• body's largest organ.

• Acts as a protective barrier
• Temperature homeostasis
• Excretion of metabolic wastes
• Sense of touch
• Synthesis of Vitamin D

• Epidermis
• Dermis
• Hypodermis

• Avascular-no direct blood supply
• Stratified squamous epithelium
• Lower layer living cells; upper layer dead filled with keratin
• Subdivided into 5 identifiable layer
• Stratum Basale- lowermost layer of epidermis; single cell layer thick
• Stratum Corneum- thickest of all layers; thickness of epidermis; dead cells completed filled with keratin; water resistant; main protection against biological and chemical assult

• Thickest layer in skin.
• Strong, flexible, connective tissues
• Gives skin its strength and resilience
• Gel-like matrix
• Rich in nerves, receptor, blood vessels, lymph vessels
• Hair follicles and sweat glands
• 2 layers:
• papillary layer (upper)
• reticular layer (lower)

• Fat tissues
• below skin

• Due to combination of 3 different pigments
• 1. melanin- yellow, orange, brown or black pigments; racial shades due mainly to kinds and amount of melanin pigments
• 2. carotene- in stratum corneum and hypodermis layer
• 3. hemoglobin- blood of skin capillaries

• Cyanosis= bluish cast--> poor oxygenation
• erythema= redness--> emotional, hypertension, inflammation
• Jaundice= yellowing--> liver disorder, bile pigments in blood.

• Hair- heavily keratinixed; consist of shaft, root, follicle, papillae, arrector pili, oil glands, hair receptor; color of hair depends on kinds of and amount of melanin
• Nails- scale like modification of epidermis
• Skin glands- oil gland, sweat gland, mammary gland (milk) ceruminous gland (ear wax)

• Burn- too much sunlight or heat. 1st degree-surface layer of skin is shed; 2nd degree-deep injury, blisters form as fluid builds up; 3rd degree- full thickness of skin is destroyed, dehydration, susceptible to infections, extend of burn damage estimated by rule of 9's
• Skin cancer - caused by UV, xray or radiaiton
• Types of cancer: actinic keratosis; basal cell carcinoma; squamous cell carcinoma; maliganant melanoma