The renal corpuscle, the initial filtering unit at the beginning of each nephron, is made up of which of the following structures?

Introduction / Context:
The nephron is the functional unit of the kidney, responsible for filtering blood and forming urine. At the very beginning of each nephron lies a structure called the renal corpuscle. Many exam questions check whether you know exactly which parts of the nephron make up this renal corpuscle. This question asks you to identify the correct combination of structures that together form the renal corpuscle.

Given Data / Assumptions:

• The structures mentioned are Bowmans capsule and the glomerulus.

• The renal corpuscle is defined in renal anatomy as the filtering unit at the start of the nephron.

• You are to decide whether the renal corpuscle consists of one or both of these structures.

• Later nephron segments such as the proximal tubule and loop of Henle are not part of the renal corpuscle.

Concept / Approach:
The renal corpuscle is composed of two main parts: a tuft of capillaries called the glomerulus and the surrounding double walled cup called Bowmans capsule. Blood enters the glomerulus through an afferent arteriole, and filtration takes place across the capillary walls and the inner layer of Bowmans capsule into the capsular space. From there, the filtrate flows into the proximal convoluted tubule. Any definition of renal corpuscle that includes only one of these parts is incomplete. Therefore, the correct answer must be the option that includes both Bowmans capsule and the glomerulus together.

Step-by-Step Solution:
Step 1: Recall that the glomerulus is a network of capillaries inside the nephron where high pressure filtration of blood occurs. Step 2: Remember that Bowmans capsule is a cup shaped structure that surrounds the glomerulus and collects the filtrate. Step 3: Understand that the term renal corpuscle refers to this combination of glomerulus and Bowmans capsule, functioning as a unit. Step 4: Check option A, which lists only Bowmans capsule. This ignores the glomerular capillary tuft and is therefore incomplete. Step 5: Check option B, which lists only the glomerulus without its surrounding capsule; this again does not match the full definition of the renal corpuscle. Step 6: Option C correctly states that both Bowmans capsule and glomerulus together form the renal corpuscle. Step 7: Option D states that none of the above structures make up the renal corpuscle, which is clearly wrong since textbook definitions use exactly these names.

Verification / Alternative check:
Diagrams of the nephron in anatomy and physiology textbooks label the renal corpuscle as a rounded structure consisting of a capillary tuft (glomerulus) enclosed by Bowmans capsule. Legends often explicitly state that this whole unit is the renal corpuscle. The tubular parts of the nephron, including the proximal convoluted tubule, loop of Henle, distal tubule, and collecting duct, are shown as separate structures downstream of the corpuscle. This consistent depiction confirms that both Bowmans capsule and the glomerulus are required to define a renal corpuscle.

Why Other Options Are Wrong:

Bowmans capsule only: Omits the glomerular capillaries, so it is not a complete renal corpuscle.

Glomerulus only: Ignores the capturing structure, Bowmans capsule, so it is incomplete.

None of the above: Directly contradicts standard kidney anatomy and is incorrect.

Common Pitfalls:
Some learners loosely use the term glomerulus when they actually mean the entire renal corpuscle, which leads to confusion in MCQs. Others may think Bowmans capsule alone is the corpuscle because it has a distinct capsule like appearance. To avoid mistakes, remember that the renal corpuscle is the combination of glomerulus plus Bowmans capsule working together as the filtration unit at the start of the nephron.

Final Answer:
The renal corpuscle is made up of both Bowmans capsule and the glomerulus together.