Describe the process of urine formation in kidneys 0
Answers
Answer:
Waste Ions and Hydrogen Ions Secreted from the Blood Complete the Formation of Urine. ... The secreted ions combine with the remaining filtrate and become urine. The urine flows out of the nephron tubule into a collecting duct. It passes out of the kidney through the renal pelvis, into the ureter, and down to the bladder.
Explanation:
Answer:
Explanation:
Formation of urine
The urine formation in the nephron takes involves three steps:
Glomerular filtration - The semi-permeable glomerular capillaries act as filters. It allows water, glucose, salts, amino acids and other nitrogenous waste materials to pass through it and enter the Bowman's capsule. The filtrate so formed is called glomerular filtrate.
Tubular reabsorption - The filtrate in the Bowman's capsule enters the Proximal convoluted tubule (PCT). About 65 % of glomerular filtrate is reabsorbed in PCT. Glucose, amino acid, vitamins, hormones, various salts, water and some urea from the filtrate is absorbed.The filtrate reaches Loop of Henle which consist of descending and ascending limb. As the filtrate flows through the descending loop of Henle only water is reabsorbed. Sodium and other solutes are not absorbed here. Further, the filtrate flows through the ascending loop of Henle where reabsorption of sodium, potassium, calcium, magnesium, and chloride are reabsorbed. The ascending loop of Henle is impermeable to water, hence no water is reabsorbed in this region. The filtrate then flows through the Distal convoluted tubule(DCT). In DCT, active reabsorption of sodium takes place under the influence of aldosterone. Chloride ions are also reabsorbed. Water is reabsorbed under the influence of ADH(antidiuretic hormone). Passing through the DCT, the filtrate enters the collecting ducts. Further reabsorption of water takes place in the collecting ducts.
Tubular secretion - Secretion is the final step in the formation of urine. Creatinine, hippuric acid, drugs etc are actively secreted into the filtrate In the proximal convoluted tubule. Urea enters the filtrate by diffusion in the thin segment of ascending loop of Henle. Potassium, hydrogen, and bicarbonate ions are secreted into the filtrate in the DCT. Removal of hydrogen ions and ammonia from the blood in PCT and DCT helps to maintain the pH of blood.
Thus the urine created by this process then passes to the central part of the kidney called the pelvis. The urine then passes from pelvis to urinary bladder through ureters.