The Bowman's capsule and glomerulus together form the renal corpuscle. Blood enters the glomerulus via the afferent arteriole and exits in the efferent arteriole.
The endothelium of the glomerulus contains pores, and lies adjacent to the capsule membrane, which also contains pores called filtration slits. This leaky endothelial-capsular membrane can therefore filter water and substances from the blood into the nephron.