Final answer:
Materials are filtered from the glomerulus because the afferent arteriole is wider than the efferent arteriole, creating high pressure in the glomerular capillaries, which aids filtration. Approximately 2 to 3 million glomeruli in the kidneys filter blood, producing around 200 liters of filtrate daily with less than two liters excreted as urine.
Step-by-step explanation:
One of the factors that cause materials to be filtered from the glomerulus is that the afferent arteriole is wider in diameter than the efferent arteriole. This arrangement creates a higher pressure within the glomerular capillaries, facilitating the filtration of blood. The glomerulus, being a tightly packed bundle of capillaries, filters the blood based on particle size, allowing water and solutes to be filtered out and excluding larger elements like blood cells and proteins. Between the two kidneys, there are about 2 to 3 million glomeruli, which collectively produce about 200 liters of filtrate every day, yet only less than two liters are excreted as urine.
The urinary system's remarkable efficiency in blood filtration is due to the structure of nephrons, of which the renal corpuscle (composed of the glomerulus and Bowman's capsule) is the first part. As blood flows through the glomerular capillaries, it is under pressure, pushing water and solutes into Bowman's capsule, initiating the filtration process. After passing through the renal corpuscle and becoming filtrate, the substances pass into the nephron tubule for further processing. The efferent arteriole then carries the remaining blood to the peritubular capillaries and vasa recta, where most of the solutes and water are reclaimed and returned to circulation.