1. Pleural: Lung cavity Pericardial: heart Peritoneal: abdominal cavity

2. All body cavities are lined by a thin membrane which has 2 parts: 1. Parital membrane: lines the body cavity 2. Visceral membrane: outer lining of the organ The serous fluid is in the space between the 2 membranes.

3.  Serous fluid: Is an ultra filtrate of plasma derived from the capillary network of the membrane. Formed under the influence of: 1. Hydrostatic pressure 2. Osmotic pressure 3. Capillary permeability.

4. Pleural fluid  Fluid in the lung cavity  It is essentially interstitial fluid of the systemic circulation  It is about 3- 20 ml under normal conditions.  Drained by the lymphatic system  Normally it’s a clear or pale yellow fluid.

5. Transudate/Excudate effusion Any alteration in the rate of formation or removal can cause effusion (accumulation of fluid in the cavity) Transudate: Secondary to pleural pathology and indicates the treatment should begin else where. Excudate: Primary involvement of the plaura and lungs and demands immediate attention.

6. TransudateExudate AppearanceClearCloudy FibrinogenAbsentPresent (clots) Total proteinLess than 30 g/LGreater than 30 g/L GlucoseSame as in plasma Less than plasma S.G1.015 ( less)1.018 ( more)

7. Abnormalities CloudyBacterial infection MilkyPresence of fatty lymph Increase in volumeCongestive heart failure, Chronic liver cirrhosis, and pneumonia High amylase activityPancreatitis, Oesophageal perforation Low PHOesophageal perforation Reduced glucoseSLE, Rheumatoid arthritis, bacterial infection

8. Thoracentesis It is the procedure in which the fluid is obtained by a needle and syringe

9. Pericardial fluid  The fluid surrounding the heart  Same as pleural fluid  Is clear and pale yellow  Volume 10- 15 ml  Low glucose in case of inflammatory diseases and bacterial infections.

10. Peritoneal fluid  Fluid in the abdominal cavity  Clear or pale yellow  > 50 ml  Access fluid is a condition called Ascites  Sampling by needle aspiration in a process called paracentesis

11. Ascites Common causes: Transudate 1. Cirrhosis 2. Congestive heart failure 3. Hypoalbuminemia Excudate: Metastatic ovarian cancer and infective peritonitis