Define Ultafiltration.

In kidneys, excretory unit is present which is known as nephron. Basic structure of nephron is as follows:

In this there is a cup shaped Bowman’s capsule in which bunch of blood capillaries is present which is known as glomerulus. To this glomerulus the blood having waste material is brought by afferent arteriole. Now since glomerulus consists of capillaries blood brought to glomerulus is under pressure and is thus filtered and is passed to Bowman’s capsule. This process of filtering blood through glomerulus is called Ultrafiltration.

Following picture also depict this process of ultrafiltration: