Search results
Results From The WOW.Com Content Network
The renal circulation supplies the blood to the kidneys via the renal arteries, left and right, which branch directly from the abdominal aorta.Despite their relatively small size, the kidneys receive approximately 20% of the cardiac output.
The renal medulla (Latin: medulla renis 'marrow of the kidney') is the innermost part of the kidney. The renal medulla is split up into a number of sections, known as the renal pyramids. Blood enters into the kidney via the renal artery, which then splits up to form the segmental arteries which then branch to form interlobar arteries.
The renal arteries are paired arteries that supply the kidneys with blood. Each is directed across the crus of the diaphragm, so as to form nearly a right angle. The renal arteries carry a large portion of total blood flow to the kidneys. Up to a third of total cardiac output can pass through the renal arteries to be filtered by the kidneys.
The concave part of the bean-shaped kidneys is called the renal hilum, through which the renal artery and nerves enter the kidney. The renal vein, collecting lymphatic vessels and ureter exit the kidney through the renal hilum. [6] [55] The kidneys are located retroperitoneally [6] on the back wall of the body of mammals. [7]
The renal lobe is a portion of a kidney consisting of a renal pyramid and the renal cortex above it. [1] In humans, on average there are 7 to 18 renal lobes. [medical citation needed] It is visible without a microscope, though it is easier to see in humans than in other animals.
The kidney is surrounded by tough fibrous tissue, the renal capsule, which is itself surrounded by perirenal fat, renal fascia, and pararenal fat. The anterior (front) surface of these tissues is the peritoneum, while the posterior (rear) surface is the transversalis fascia. The superior pole of the right kidney is adjacent to the liver.
The first step in urine formation is the filtration of blood in the kidneys. In a healthy human, the kidney receives between 12 and 30% of cardiac output, but it averages about 20% or about 1.25 L/min. The basic structural and functional unit of the kidney is the nephron.
Its central part presents a deep longitudinal fissure, bounded by prominent overhanging anterior and posterior lips. This fissure is a hilum that transmits the vessels, nerves, and ureter. From anterior to posterior, the renal vein exits, the renal artery enters, and the renal pelvis exits the kidney.