INTEGUMENTARY SYSTEM SKIN & BODY MEMBRANES. MEMBRANES: An overview Defined:Defined: –Superficial...
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Transcript of INTEGUMENTARY SYSTEM SKIN & BODY MEMBRANES. MEMBRANES: An overview Defined:Defined: –Superficial...
MEMBRANES: An overview• Defined:
– Superficial layer of epithelial cells– underlying layer of supportive connective tissue
• Structure: Thin, sheet-like structure
Membranes: Functions
• Functions:– Cover and protect the body surface, internal
organs– Line the body cavities, inner surface of hollow
organs– Anchor organs to each other or to bones– Secrete lubricating fluids that reduce friction
during organ movements
Two Types of Body Membranes
• 1) Connective Tissue Membranes• 2) Epithelial Membranes
– Serous membranes– Mucous membrane– Cutaneous membrane (skin)
Connective: Synovial Membrane
• Structure– No epithelial layer –
connective only– Smooth & slick
Connective: Synovial Membrane
• Function: – Lines capsules b/w joints that move– Lines bursa sacs– Secrete synovial fluid– Reduce friction b/w opposing bones
Epithelial: Serous Membranes• Found only on surfaces within closed cavities• 2-layer structure:
– Epithelial – thin layer of simple, squamous epithelium
– Connective – thin, glue-like basement membrane that holds and supports
Serous Membranes: Function
• Function: Protection/reduce friction for organs• Two Types (1 continuous layer):
1. Visceral: covers the surface of the organ2. Parietal: lines the walls of the body cavity
• Thoracic Cavity/Lungs=Pleura• Abdominal Cavity=Peritoneum
– What is pleurisy? – What is peritonitis?
Epithelial: Mucous MembraneSecretes Mucus: moistens, lubricates, protectsLines body surfaces opening directly to exterior
(respiratory, digestive, reproductive & urinary tracts)
Structure: - Epithelium varies depending on location,
function
Epithelial: Cutaneous Membrane (SKIN)
• FUNCTIONS– Protection against microbes, UV rays, harmful
chemicals, cuts & tears– Temperature regulations– Sense organ activity: touch, pressure, pain,
temperature– Metabolic functions: synthesis of vitamin D
Skin: Structure• Structure: 2 Layers:
1. Epithelial: Epidermis • outermost & thinnest• cells are very tightly packed
2. Connective: Dermis • deep & thick• primarily connective tissue• loosely packed
• Hypodermis (adipose tissue)– Deep to the skin/dermis– Layer of insulation
Epidermis• Outermost: Stratum
corneum– Dry, dead, – keratin filled (waterproof,
tough)• Statum germinativum /
basale– Cells undergoing mitosis,
move up – “Pigment layer”
Stratum corneum: Dead squamous cells
Stratum Germanitivum/Basale: dividing columnar cells
Stratum Spinosum: cuboidal cells, desmosomes hold together >> spiny
Stratum granulosum: Granules with lipids and keratin – forms waterproof layer
Stratum lucidum: oils from lysosome disintegration