SKIN AND BODY MEMBRANES


ORGANS


groups of tissues working together to perform a common function


2 DIFFERENT TYPES OF TISSUES:


EpithelialConnective


4 DIFFERENT KINDS OF MEMBRANES IN THE BODY:


MucousSerousSynovial Cutaneous


What is mucous and its function?


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.


What is serous & its functions?


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

Functions: secretes serous fluid for lubriationthorax-pleuraabdominal-peritoneumheart-pericardium


What is synovial & its functions?


Synovial- lines joint cavities. Ex: connective tissues only

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


What is cutaneous & its functions?


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


Integumentary System (Skin)


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


General function of Integumentary system (Skin)


Acts as a protective barrierTemperature homeostasisExcretion of metabolic wastesSense of touchSynthesis of Vitamin D


Layers of Skin


EpidermisDermisHypodermis


Epidermis


Avascular-no direct blood supplyStratified squamous epitheliumLower layer living cells; upper layer dead filled with keratinSubdivided into 5 identifiable layerStratum Basale- lowermost layer of epidermis; single cell layer thickStratum Corneum- thickest of all layers; thickness of epidermis; dead cells completed filled with keratin; water resistant; main protection against biological and chemical assult


Dermis (hide)


Thickest layer in skin.Strong, flexible, connective tissuesGives skin its strength and resilienceGel-like matrixRich in nerves, receptor, blood vessels, lymph vesselsHair follicles and sweat glands2 layers: papillary layer (upper) reticular layer (lower)


Hypodermis (subcutaneous)


Fat tissuesbelow skin


Skin Color


Due to combination of 3 different pigments1. melanin- yellow, orange, brown or black pigments; racial shades due mainly to kinds and amount of melanin pigments2. carotene- in stratum corneum and hypodermis layer3. hemoglobin- blood of skin capillaries


Skin colors and textures in diagnosis:


Cyanosis= bluish cast--> poor oxygenationerythema= redness--> emotional, hypertension, inflammationJaundice= yellowing--> liver disorder, bile pigments in blood.


Derivitives of Skin:


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 melaninNails- scale like modification of epidermisSkin glands- oil gland, sweat gland, mammary gland (milk) ceruminous gland (ear wax)


Skin Imblances and Aging


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'sSkin cancer - caused by UV, xray or radiaitonTypes of cancer: actinic keratosis; basal cell carcinoma; squamous cell carcinoma; maliganant melanoma