In this lesson, you will learn about the blood supply to the kidneys. We will look at the arteries leading to the kidneys as well as the venous drainage from the kidneys.
One of the main functions of the kidneys is to clean the blood. 20% of the blood that leaves the heart goes to the kidneys.
The Arterial System
Here are the main arteries involved in supplying the kidneys with blood:
The aorta is the major blood vessel leaving the heart and taking the blood to most of the body. It goes through the thoracic region and into the abdominal region.
The left and right renal arteries take the blood from the abdominal aorta to the left and right kidneys. The renal arteries then branch into the segmental arteries, which branch into the interlobar arteries.
These interlobar arteries take the blood between the renal pyramids (lobes). As the interlobar arteries curve around the renal pyramids, they become the arcuate arteries. These arcuate arteries then branch into the interlobular arteries.
From the glomerulus, the blood goes into the efferent arterioles and then the peritubular capillaries.
The blood then enters the venous system as it leaves the kidneys.
The Venous System
From the peritubular capillaries, the deoxygenated blood enters the interlobular veins then the arcuate veins. It drains into the interlobar veins and then goes via the renal veins.
From the renal veins, the blood enters the inferior vena cava and then returns to the heart.
Notice that the vessels of the venous system are named similarly to those of the arterial system.
In some textbooks, you will see the presence of segmental veins and in others, you won’t.
That’s the blood supply to the kidneys. In the next lesson, we will dig into the structure and function of the nephron, which is the functional unit of the kidney.