Which substance would not be found in the glomerular filtrate under normal conditions?

• A. Urea
• B. Albumin
• C. Glucose
• D. Sodium ions

Answer: (B)

Verified step by step guidance

1. Understand the process of glomerular filtration: The glomerulus is a network of capillaries in the kidney where blood filtration begins. The filtration barrier allows water and small solutes to pass into the Bowman's capsule, forming the glomerular filtrate.
2. Identify the substances typically found in the glomerular filtrate: Under normal conditions, the filtrate includes water, electrolytes (such as sodium ions), glucose, and waste products like urea.
3. Consider the size and charge of molecules: The filtration barrier prevents large molecules and negatively charged proteins from passing through. Albumin, a large protein, is typically too large to pass through the filtration barrier.
4. Review the role of albumin: Albumin is a protein that helps maintain oncotic pressure in the blood vessels and is not normally found in the glomerular filtrate due to its size and charge.
5. Conclude which substance is not found in the filtrate: Based on the size exclusion principle of the glomerular filtration barrier, albumin is not found in the glomerular filtrate under normal conditions.