In renal physiology, which structure is primarily responsible for filtering the blood to form the initial filtrate?

• A. The glomerulus (capillary tuft within the renal corpuscle)
• B. The proximal convoluted tubule
• C. The collecting duct
• D. The loop of Henle

Answer: (A)

Verified step by step guidance

1. Understand the process of urine formation in the nephron, which involves filtration, reabsorption, and secretion.
2. Identify the part of the nephron where blood filtration first occurs; this is the initial step in forming the filtrate from blood plasma.
3. Recall that the renal corpuscle consists of two main parts: the glomerulus (a capillary tuft) and Bowman's capsule.
4. Recognize that the glomerulus is the network of capillaries where blood pressure forces water and solutes out of the blood, initiating filtration.
5. Conclude that the glomerulus is primarily responsible for filtering the blood to form the initial filtrate, before it passes into the proximal convoluted tubule.