In which region of the nephron, does Ultrafiltration occur?

Bowman's Capsule, the beginning of the renal tubule in the nephron, is where ultrafiltration occurs.

Bowman's capsule is a network of blood vessels in the kidney that surrounds the glomerulus. Blood pressure in the glomerulus generates filtration pressure, which drives the filtration of plasma from the blood, including water, electrolytes, and waste products, into the lumen of Bowman's capsule. This filtrate is then processed in the renal tubule, where necessary components are reabsorbed back into the blood and waste products are excreted in the urine.

The PCT, the Loop of Henle, and the DCT all play a role in filtering the filtrate and controlling the reabsorption and excretion of various substances.

Ultrafiltration, on the other hand, occurs only in Bowman's Capsule.