The venules are tiny blood vessels that return blood to the veins. Only 25 percent of a humans blood are contained in the venules.
The blood in venules of the systemic circulation is deoxygenated. The blood in pulmonary venules is oxygenated.
venules
in your body
Small postcapillary venules consist entirely of endothelium just like capillaries (the larger venules have smooth muscle and thin externa as well). Also both capillaries and venules have no elastic tissues. Postcapillary venules are extremely porous which makes them more like capillaries then veins, and fluid and WBC's move easily into the bloodstream through these walls.
Venules
Venules
capillaries
Capillaries
Veins
Renal vein It is not renal vein. It is venules. renal vein is only at one point of the body, were talking capillaries; which are all over the body.
Venules
veins and venules