Which one of the following does not occur when blood passes through most systemic capillary beds? a. the ph of the blood decreases. b. the partial pressure of o2 in the blood decreases. c. the number of erythrocytes per μl of blood increases. d. water, ions and proteins diffuse from the plasma into the interstitial space. e. per unit time, the volume of blood leaving the capillary in the downstream venule is more than the volume of blood that entered the capillary from the upstream arteriole.