Final answer:
Blood is delivered to the kidneys via the renal artery, leading to filtration in the nephrons and reabsorption of essential substances into the bloodstream.
Step-by-step explanation:
Blood flows from the renal artery into the kidney, where it is filtered.
Here is the explanation of how blood is filtered in the kidney: Blood enters the kidney via the renal artery. This artery branches into smaller vessels that distribute blood to the nephrons, the functional filtering units of the kidneys. In the glomerulus, a cluster of capillaries within the nephron, the blood pressure forces water and dissolved substances out of the blood and into Bowman's capsule. These substances form the filtrate, which then travels through the renal tubule. Throughout the tubule's different segments, such as the loop of Henle and the distal convoluted tubule, useful substances are reabsorbed back into the bloodstream, whereas waste substances are secreted into the filtrate. The cleaned blood exits the kidney through the renal vein, while the filtrate, now concentrated as urine, drains into the ureters.
The renal artery carries blood with waste products into the kidney. Within the nephron, which is the structure that filters the blood, the blood pressure forces water and dissolved substances out of the blood and into Bowman's capsule. The filtered substances then pass into the renal tubule of the nephron for further processing.