How urine is produced in Human Body?

Process: In the glomeruli, blood pressure forces water, salts, glucose, amino acids, and urea (a waste product) through a filter into the Bowman’s capsule, creating a filtrate. Larger molecules like proteins and blood cells are typically retained in the blood.

2. Reabsorption

Location: Renal Tubules (Proximal Convoluted Tubule, Loop of Henle, Distal Convoluted Tubule)

Function: The filtrate then flows through the renal tubules where essential substances are reabsorbed back into the bloodstream.

Process: In the proximal convoluted tubule, much of the water, glucose, and salts are reabsorbed. The Loop of Henle plays a key role in concentrating the urine by reabsorbing water and salts. In the distal convoluted tubule, further fine-tuning occurs to regulate the balance of electrolytes and acids.

3. Secretion

Location: Renal Tubules

Function: Additional waste products and excess ions are secreted from the blood into the renal tubules.

Process: This helps in regulating the body’s pH and electrolyte balance by removing excess hydrogen ions, potassium, and other substances.

4. Excretion

Location: Collecting Ducts, Renal Pelvis, Ureter, Bladder, Urethra

Function: The final filtrate, now called urine, flows from the renal tubules into the collecting ducts. From the collecting ducts, urine moves into the renal pelvis, then into the ureters.

Process: The ureters transport urine to the bladder, where it is stored. When the bladder fills, stretch receptors signal the need to urinate. Urine is then expelled from the bladder through the urethra during urination.

Key Points to Remember

• Blood Supply: The kidneys receive a substantial amount of blood, around 20-25% of the cardiac output, to effectively filter and produce urine.
• Regulation: The kidneys help regulate blood pressure, electrolyte levels, and the body’s overall fluid balance. Hormones such as antidiuretic hormone (ADH) and aldosterone play crucial roles in these regulatory processes.

The entire process ensures that waste products are efficiently removed from the body while retaining essential nutrients and maintaining fluid and electrolyte balance.

For more information, contact Dr. Debabrata Mukherjee – Best Nephrologist in India.