Biology - Blood and Tissue fluid

• Capillaries


  Extensive networks of thin-walled blood vessels where substances are exchanged between the blood and body cells
• Capillaries


  • Extremely thin wall consisting of a single layer of endothelial cells
  • Short diffusion distance between blood and surrounding cells
  • Diameter slightly greater than red blood cell, causing them to be pressed against the wall
  • Red blood cells travel through in single file at a slower speed
• Diffusion in capillaries


  1. Oxygen and glucose diffuse from blood to body cells

  2. Waste products like carbon dioxide diffuse from cells back to blood
• Tissue fluid


  Fluid that bathes the cells, providing essential molecules like glucose and amino acids
• Capillary wall


  • Contains small gaps between endothelial cells
  • Allows tissue fluid to pass out of the blood
  • Allows white blood cells to leave the bloodstream
• Capillary beds provide a massive surface area for exchange of materials
• Capillaries


  Extensive networks of thin-walled blood vessels that allow exchange of substances between blood and body cells
• Capillaries


  • Extremely thin wall consisting of a single layer of endothelial cells
  • Very short diffusion distance between blood and surrounding cells
  • Diameter slightly greater than red blood cell, causing them to be pressed against the wall
  • Red blood cells travel through in single file at a slower speed
• Exchange of substances between blood and body cells in capillaries

  1. Oxygen and glucose diffuse from blood to cells

  2. Waste products like carbon dioxide diffuse from cells to blood
• Tissue fluid


  Fluid that bathes the cells, providing essential molecules
• Capillary wall


  • Contains small gaps between endothelial cells
  • Allows tissue fluid to pass out of blood
  • Allows white blood cells to leave the bloodstream
• Extensive branching of capillaries provides a massive surface area for exchange of materials
• Capillaries are adapted to maximize the rate of diffusion of molecules like oxygen