AEMCA Practice Exam

Which structure in the renal blood flow is responsible for filtering blood?

1. Renal tubule

2. Afferent arteriole

3. Glomerulus

4. Efferent arteriole

The correct answer is: Glomerulus

The glomerulus is the structure responsible for filtering blood in the renal blood flow. It is a network of tiny blood vessels, or capillaries, that acts as the initial site of filtration in the kidneys. Blood enters the glomerulus through the afferent arteriole, where pressure forces water and small solutes out of the blood and into the Bowman’s capsule, initiating the formation of urine. This filtration process selectively removes wastes, excess substances, and water, while larger molecules and blood cells generally remain in the bloodstream. In contrast, the renal tubule is involved in the reabsorption and secretion processes after filtration has occurred, rather than being the site of filtration itself. The afferent arteriole simply delivers blood to the glomerulus but does not play a direct role in the filtration process. The efferent arteriole carries blood away from the glomerulus, again not contributing to the filtration function but instead helping regulate blood flow and pressure within the nephron. Thus, the filtration function is exclusively attributed to the glomerulus in the renal blood flow system.