Question

Describe the process of urine formation in the kidney.​

Answer 1

Answer:

There are three different stages in the formation of urine by the filtration of blood through the nephrons. The process of urine formation in kidneys include the following steps:

(i) Glomerulas filtration - Urine formation begins when the blood is filtered by the glomerulus then enters the Bowman's capsule and the glomerular filtrate is formed. The afferent arteriole entering the glomerulus is wider than the efferent arteriole in diameter. This increases the blood pressure within the glomerulus helps in the filtration. Glomerular filtrate is formed of all blood constituents except corpuscles and plasma proteins.

(ii) Tubular reabsorption - When the glomerular filtrate comes to the proximal tubule then the essential nutrients are reabsorbed. Glucose, amino acids, water, ions like sodium, potassium, chloride, bicarbonate, magnesium, calcium are reabsorbed from the glomerular filtrate. When the filtrate finally comes to the collecting duct ADH (anti-diuretic hormone) acts and reabsorbs the excess water and decreases the urine volume.

(iii) Tubular secretion - When the glomerular filtrate is in the proximal tubule creatinine, uric acid are secreted in it. When the filtrate goes to the distal part urea, potasium ion and some hydrogen ions are secreted in the form of urine.

Answer 2

Explanation:

The kidneys filter unwanted substances from the blood and produce urine to excrete them. There are three main steps of urine formation: glomerular filtration, reabsorption, and secretion. These processes ensure that only waste and excess water are removed from the body.