A. True It depends on pore size and hydrostatic pressure gradients; colloids are larger particles than crystalloids.
B. False Substances cross cellular walls by active transport or down electrochemical gradients; hydrostatic pressure gradients are not involved.
C. True An outward hydrostatic pressure gradient exists at the arterial end of the capillary.
D. True The pressure gradient across glomerular capillary walls is greater than that in other capillaries.
E. True But active secretion is also involved in the formation of CSF.