When trying to explain to a new dialysis patient the movement of substances through the capillary pores, the nurse will explain that in the kidneys, the glomerular capillaries have:

a) No capillary openings since this would lead to extensive hemorrhage.
b) Endothelial cells that are joined by tight junctions that form a barrier to medication filtration.
c) Small openings that allow large amounts of smaller molecular substances to filter through the gomeruli.
d) Large pores so that substances can pass easily through the capillary wall.