Question

Why afferent arteriole is larger in diameter than efferent arteriole?

Answer 1

The diameter of efferent arteriole is less than that of the afferent arteriolebecause pressure builds up in thearteriole and some of the fluid is forced to go through the gaps in cells of Bowman's capsule (podocytes). This filters the blood, and this process is called ultrafiltration

Answer 2

Answer:

The diameter of afferent arteriole is bigger than efferent arteriole to produce an extraordinary force of blood in the glomerulus which directly contributes in the efficiency of ultrafiltration of the blood and production of the pre-urine which then passes down the convoluted tubules for reabsorption.