Odema Flashcards
What is oedema
An accumulation of excess fluid in the interstitial spaces
Spaces around the cells that make up tissue
What is effusion
An increase in amount of synovial fluid without a joint capsule and is a reactive response by the synoviocytes to irritation or trauma
Only around synovial joints due to synoviocytes
Extracellular fluid
20% blood plasma
80% interstitial fluid
Causes of oedema
INFLAMMATION: vasodilation and increased permeability of capillary so rate is filtration increases eg damage capillary wall localised swelling
NON INFLAMMATION:
Decrease concentration of plasma proteins eg kidney liver disease etc
Alteration of harmodynamics eg left ventricular heart failure which will increase hydrostatic pressure
Blocked lymphatics eg malignancy can’t remove fluid fast enough
Malnutrition- own cells as a source of nutrition
Capillaries
Single layer squammous epithelial cells pores between induak cells 8 micro meters
Permiate most tissues
Intricate network muscles tissues branch beneath the epithelial bass lamina
Only blood vessels that walls permit the exchange between the blood and surrounding interstitial tissues
Slow blood flow allow time for exchange- diffusion or active transport
Continuous capillary is most common = small nutrient molecules filter out RBC too big to filter out
Extracellular fluid
Extracellular fluid=
Fluid outside of body cells within body controls homeostasis by maintaining osmotic balance between capillary bed and interstitial spaces allow diffusion filtration absorption
20% blood plasma and 80% interstitial fluid
Blood plasma: straw colours fluid hold blood cells
Interstitial fluid: surrounds tissue makes up majority of extracellular fluid provides body with the means if removal of waste products
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Solute concentration
Hydrostatic pressure
Pressure declines from arteriolar end to venous end
**Osmotic pressure relatively stable
Net movement out at arteriole end and in at venous end -see diagram
Water low to high osmotic pressure
and a high to low hydrostatic pressure net flow determined by the balance of hydrostatic and colloid pressure more filtration than absorption
Filtration abd absorption in capillary bed
24 L of fluid out of capillary bed into interstitial fluid
20.4 L if fluid absorped remaining flows through the tissues and lymphatic system and eventually returns to Venus system
Continuous movement of water out of capillaries and through periferal tissues and back to blood stream has 4 functions
- Ensure plasma and interstitial fluid have constant communication and mutual exchange
- Accelerate distribution of hormones gases nutrients to tissues
- Assist transport of insoluble lipids and tissue proteins that can’t re enter the blood stream by crossing capillary walls
- Flushing actions that carry bacterial toxins and other chemical stimuli to lymphoid tissues and other organs responsible for providing immunity
(6) factors that contribute to oedema
- Increased hydrostatic pressure
- Reduced osmotic pressure
within blood vessels - increased tissue osmotic pressure
- increased blood vessel wall permeability (inflammation)
- Obstruction of fluid clearance of lymphatic system
- Changes in water retaining properties in tissue themselves (raised hydrostatic pressure)
Oedema x2 pathways
Soft mobile swelling
- Resolution
- fluid reabsorbed by healing process swelling goes down
- organisation build up of fibrous cells
- Becomes hard and consolidated and not reabsorbed