Glomerular Filtrate
You have studied earlier that a mammalian nephron has a renal corpuscle consisting of Bowman's capsule enclosing glomerulus. Blood entering the glomerulus through the afferent arteriole is filtered into the lumen of the Bowman's capsule to give rise to the ultrafiltrate. The glomerular filtrate is nearly isosmotic to plasma and contains ions and other solutes of small size essentially at the same concentrations as in the plasma. The blood pressure in the glomerular capillaries provides the driving force for filtration.