Edema Flashcards
Where does fluid exchange between plasma and interstitium occur? and why ?
- Occurs at the capillaries
- Due to:
- Hydrostatic pressure
- Oncotic pressure
Define Hydrostatic pressure (HP)
•Pressure exerted by fluid on the wall of a
blood vessel
What are two types of Hydrostatic pressure?
- Capillary HP (HPC)
* Interstitial fluid HP (HPISF)
Define Oncotic pressure (OP)?
•Osmotic pressure of plasma protein
What are two types of oncotic pressure?
- Capillary OP (OPC)
* ISF OP (OPISF)
What happens at the arterial end of capillaries?
•The hydrostatic pressure > oncotic
What happens at the venous end of capillaries:
•The oncotic pressure < hydrostatic
•About 90% of filtered fluid is absorbed
at__________
the veniolar end of capillaries
•The remaining 10% of filtered fluid is
absorbed by________
the lymphatic vessels
Define Edema
•Edema is defined as abnormal
collection of fluid in the interstitium
Edema results from
disturbance of
balance between filtration and
absorption of fluid at the
capillaries
What are the mechanisms of edema?
1- High hydrostatic pressure
2- Low oncotic pressure
3- Lymphatic obstructing
4- Increased permeability of capillaries (to protein)
What are the causes of High hydrostatic pressure?
- Heart failure
- Venous obstruction
What are the causes of Low oncotic pressure?
- Malnutrition
- Malabsorption
- Liver disease (chronic)
- Renal disease (nephrotic syndrome)
What are the causes of Lymphatic obstructing?
Filariasis (elephantiasis)
Tumors
Surgical removal of lymph nodes
