FORMATION

• HOW IS TISSUE FLUID FORMED?

  ultrafiltration
• WHY DOES ULTRAFILTRATION HAPPEN?

  capillaries have small gaps in the walls so liquid and small molecules can be forced out
• WHAT IS FORCED OUT IN ULTRAFILTRATION?

  • water
  • dissolved minerals and salts
  • glucose
  • small proteins and AAs
  • fatty acids
  • oxygen
• WHAT REMAINS IN THE CAPILLARIES DURING ULTRAFILTRATION?

  • RBCs
  • platelets
  • large proteins
• PROCESS OF ULTRAFILTRATION?

  1. High hydrostatic pressure in arteriole end due to RBCs and plasma proteins being too large to move out of capillary
  2. Lower hydrostatic pressure outside capillary
  3. Small molecules in blood plasma forced out down hydrostatic pressure gradient
  4. Forming tissue fluid
• WHY CAN FORMATION OF TISSUE FLUID OCCUR?

  hydrostatic pressure is greater than osmotic pressure
• HOW DOES TISSUE FLUID MOVE IN AND OUT OF CAPILLARIES?

  through gaps in capillary endothelium that make the capillary permeable