11. Fluids in the Potential Spaces

• What is the primary characteristic of the surfaces in potential spaces?

  They almost touch with a thin fluid layer
• What type of fluid lubricates the surfaces in potential spaces?

  A viscous proteinaceous fluid
• How do fluids, electrolytes, and proteins move in potential spaces?

  They move back and forth with relative ease
• What does the presence of potential spaces indicate about their structure?

  They function as large tissue spaces
• What happens to fluid in capillaries adjacent to potential spaces?

  It diffuses into interstitial fluid and potential space
• How do proteins collect in potential spaces?

  Through leakage out of the capillaries
• How are proteins removed from potential spaces?

  Through lymphatics or other channels
• What is the term for fluid accumulation in potential spaces?

  Effusion
• What causes effusion in potential spaces?

  Edema in adjacent subcutaneous tissues
• What is the specific term for effusion fluid in the abdominal cavity?

  Ascites
• How much ascitic fluid can accumulate in serious cases?

  20 liters or more
• What can cause swelling in potential spaces during generalized edema?

  Injury or local infection blocking lymph drainage
• How does fluid pressure in potential spaces compare to subcutaneous tissue?

  It is negative in both states
• What is the normal interstitial fluid hydrostatic pressure in the pleural cavity?

  About −7 to −8 mm Hg
• What is the normal interstitial fluid hydrostatic pressure in joint spaces?

  About −3 to −5 mm Hg
• What is the normal interstitial fluid hydrostatic pressure in the pericardial cavity?

  About −5 to −6 mm Hg