Anatomy and Physiology II Practice Test

What is a tuft or network of capillaries involved in filtration called?

1. Loop of Henle

2. Glomerulus

3. Bowmann's capsule

4. Proximal convoluted tubules

The correct answer is: Glomerulus

The tuft or network of capillaries involved in filtration is known as the glomerulus. This structure is a crucial component of the nephron in the kidney, playing a vital role in the process of ultrafiltration. The glomerulus is situated within the Bowman's capsule, which surrounds it and collects the filtrate produced during the filtration process. As blood flows into the glomerulus, it is filtered under pressure, allowing water, ions, and small molecules to pass through the capillary walls into the Bowman's capsule while retaining larger molecules and blood cells within the bloodstream. This initial filtration step is essential for the formation of urine, as it determines the composition of the filtrate that will be further processed in the nephron. The other choices, while related to renal function, do not refer to the specific vascular structure responsible for filtration. The Loop of Henle is involved in the concentration of urine, Bowman's capsule serves as the container for the filtrate, and the proximal convoluted tubules are primarily responsible for the reabsorption of nutrients, but none of these options involves the network of capillaries central to the filtration process like the glomerulus does.