Each nephron is composed of a renal corpuscle/tubule (Glomerulus within Bowman's capsule), a proximal tubule (convoluted and straight components), an intermediate tubule (loop of Henle), a distal convoluted tubule, a connecting tubule, and cortical, outer medullary, and inner medullary collecting ducts.
As blood flows into each nephron, it enters a cluster of tiny blood vessels, the Glomerulus. The thin walls of the glomerulus allow smaller molecules, wastes, and fluid mostly water to pass into the tubule. Larger molecules, such as proteins and blood cells, stay in the blood vessel.