Which of these materials is/are Not filtered from the blood at the glomerulus?

Options

A. Water
B. Urea
C. Protein
D. Sodium ions

Answer

To determine which materials are not filtered from the blood at the glomerulus, we can follow these steps:

### Step 1: Understand the Structure of the Nephron
The nephron is the functional unit of the kidney, consisting of two main parts: the glomerulus and the renal tubule. The glomerulus is a tuft of capillaries where blood filtration occurs.

**Hint:** Remember that the nephron is the basic structural and functional unit of the kidney.

### Step 2: Identify the Function of the Glomerulus
The primary function of the glomerulus is ultrafiltration of the blood. It filters out various substances from the blood while retaining certain components.

**Hint:** Think about what happens during the filtration process in the glomerulus.

### Step 3: Know What Gets Filtered
During filtration, most substances, including water, urea, glucose, and sodium ions, are filtered out of the blood. However, larger molecules and cells are not filtered.

**Hint:** Consider the size of the molecules and cells that can pass through the filtration barrier.

### Step 4: Identify Components Not Filtered
The glomerulus does not filter out proteins (such as albumin) and blood cells (like red blood cells, white blood cells, and platelets). These components are too large to pass through the filtration barrier.

**Hint:** Recall that proteins and blood cells are generally retained in the bloodstream.

### Step 5: Analyze the Options Given
Given the options provided (assuming they include substances like urea, sodium ions, and proteins), we can conclude that proteins are the materials that are not filtered from the blood at the glomerulus.

**Hint:** Compare the options to determine which one is a large molecule that cannot be filtered.

### Final Answer
The material that is not filtered from the blood at the glomerulus is **Proteins**.