First step in urine formation is (a) Tubular secretion (b) Tubular reabsorption (c) Ultrafiltration (d) Selective secretion
Option C. Glomerular filtration is the first step in urine formation. Glomerular blood is filtered through filtration slits present in Bowman's capsule. The Bowman's capsule collects the filtrate and it enters the tubules of the nephron. Glomerular filtration is also called as ultrafiltration because filtrate consists of almost all constituents of plasma except proteins. Hence the first step in urine formation is Ultrafiltration.
