tissue fluid

• what does blood consist of

  plasma ,blood cells and colloidal plasma proteins
• How is tissue fluid formed?

  at the capillary bed fluid escapes through gaps between cells in the capillary walls
• what molecules are required by cells


  oxygen ,amino acids and glucose
• what waste products are removed from cells


  co2 and urea
• What is hydrostatic pressure?


  this is the pressure exerted from the contraction of the left ventricle
• at the atrial end what does the hydorsatic pressure cause in the capillaries


  it forces the fluid through gaps in the capillary walls
• at the atrial end what is the outward flow of fluid opposed by


  osmotic pressure
• what is meant by the atrial end of a capillary


  this is the beginning section of the capillary where tissue fluid is pushed out
• what happens when the hydrosatic pressure is greater then the osmotic pressure


  there is a net flow of fluid out of the blood
• how are molecules dissolved int he tissues move into the cells


  by diffusion and facilitated diffusion
• what is the venous end of capillary


  this the at the other end of the arterial end of the capillary and is where the tissue fluid flows back into the cells
• What does tissue fluid contain once it is removed form the capillary ?


  waste substances from the cells
• how does the fluid tissue without waste materials move back into the blood

  it diffuses down the concentration gradient
• why is there a lower hydrostatic pressure at the venous end of the capillary


  due to the friction between the blood and the capillary and due to the lower volume of fluid in the capillaries
• what lowers the water potential in the blood

  the presence of plasma proteins
• what does the lower water potential mean about osmatic pressure in the blood


  the osmatic pressure is greater then the hydrostatic pressure so the water moves back into the blood
• how much of the tissue fluid flows back into the capillaries


  90%