Question

Describe the process involved in the formation of urine with 200-300 words.

Answer 1

• Our kidneys tend to filter the unwanted substances from the blood and produce urine to excrete those unwanted substances.There are three steps involved in the formation of urine:-glomerular filtration, reabsorption, and secretion.This process ensures that only wastes and excess water is filtered through the body.
• Glomerular filtration-Our kidneys contain million of tiny structures called nephrons and each nephron has a glomerulus which is the site of blood filtration.The glomerulus is a network of capillaries which is surrounded by a cuplike structure called the glomerular capsule or Bowman’s capsule).When the blood tends to flow through the glomerulus,the blodd pressure pushes water and soluted from our capillaries into the bowman's capsule through a filtration membrane.This filtration begins the formation of urine in the body.
• The blood pressure inside the glomerulus is pushing the fluid from our capillaries into the capsule through a layer called the filtration membrane which allows the water and solutes to pass but tends to block the blood cells and large proteins.they remain in the bloodstream and the fluid which has passesd through the membrane tends to flow from the capsule further into the nephron.
• Reabsorption-Now,the glomerulus filters out the water and solutes from the bloodstream and the resulting filtrate contains all the waste including other substances which the body needs like essential ions,glucose,amino acids etc.
• the filtrate in the glomerulus flows through a duct in the nephron called the renal tubule,and when it flows the needed substances and some water is reabsorbed through the tube wall.This reabsorption of the important nutrients from the flowing filtrate is the next step in urine formation.
• Secretion-When the filtrate is reabsorbed in the renal tubule,some waste ions and hydrogen ions pass from the capillaries into the tubule.This next step is called secretion.
• the secreted ions get combined with the remaining filtrate and form urine which flows out the nephron tubule into a collecting duct and then passes out of the kidney through the renal pelvis,into the ureter and finally down the bladder.