ANATOMY

Detailed explanation-1: -The kidneys remove urea from the blood through tiny filtering units called nephrons. Each nephron consists of a ball formed of small blood capillaries, called a glomerulus, and a small tube called a renal tubule.

Detailed explanation-2: -The bean-shaped kidneys filter waste products out of the bloodstream and dispose of them by creating urine. Urine is made of these waste products dissolved in water.

Detailed explanation-3: -Urea is concentrated in the collecting duct lumen until the fluid reaches the urea-permeable terminal inner medullary collecting duct where urea is reabsorbed into the inner medullary interstitium via the UT-A1 and UT-A3 urea transporters.

Detailed explanation-4: -Kidney structure and function The kidneys filter the blood and then reabsorb all the useful materials such as glucose. After it has been purified the blood returns to the circulation through the renal vein. The kidney makes urine from the excess water, salts and urea.

Detailed explanation-5: -Urea is filtered across the glomerulus and enters the proximal tubule. The concentration of urea in the ultrafiltrate is similar to plasma, so the amount of urea entering the proximal tubule is controlled by the GFR. In general, 30%–50% of the filtered load of urea is excreted.