C. Structures required to perform function 1. Bowman's capsule epithelial cells called podocytes surround each capillary and form filtration slits through which the filtrate passes together with other epithelial cells not in contact with the capillaries, podocytes form a space in which the initial filtrate is collected b. Formation of the ultrafiltrate ii. Hydrostatic pressure of blood in the capillary is high, and fluid is forced out of the capillary into the Bowman's capsule. GFR depends on difference between osmotic pressure and hydrostatic pressure in capillary.
Hydrostatic pressure is regulated by constriction or dilation of afferent or efferent arterioles.
GFR also depends on rate of flow of blood in the rest of the body and the permeability of the glomerular capillaries. Permeability of capillaries can be changed by prostaglandins and other hormones. What's filtered i. Water ii. Consequence of filtration - Osmotic pressure in capillaries rises 2. Water and chloride follow because the tubule is permeable to both.