last updated 24-06-2024


Renal function

Kidneys are responsible for the excretion of water and waste products of general metabolism, such as uric acid, urea and creatinine. Furthermore, the kidneys are involved in the regulation of water, salt and acid-base balance. Thereby, the kidneys play an important role in osmo- and volume regulation, The renal system is also involved in the regulation of various ion concentrations, such as potassium, calcium and phosphate. Blood pressure forces fluid and solutes out of the glomerular capillaries into Bowman's capsule.

The filtrate is now in the first part of the renal tubule, the proximal (convoluted) tubule. Then the tubular fluid flows into the descending limb of the loop of Henle and continues its way in the ascending limb. Via the early and late distal (convoluted) tubules the fluid is collected in the collecting duct. During the passage in the renal tubule more than 90% of the water and useful solutes are reabsorbed, some waste products are secreted. Finally, water, solutes and waste products are excreted as urine.


In a glomerulus, the afferent artery carries blood towards the glomerulus. 


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