The ________________ is the finest layer of the filtration membrane.

• A. Fenestrated endothelium of the glomerular capillaries.
• B. Basal lamina.
• C. Filtration slits of the podocytes.

Answer: (C)

Verified step by step guidance

1. Understand the structure of the filtration membrane in the kidneys, which is crucial for the process of filtering blood to form urine.
2. Identify the three main components of the filtration membrane: the fenestrated endothelium of the glomerular capillaries, the basal lamina, and the filtration slits of the podocytes.
3. Recognize that the fenestrated endothelium is the first layer that allows the passage of water and small solutes but restricts larger molecules and cells.
4. Learn that the basal lamina acts as a selective barrier, further restricting the passage of larger proteins and molecules.
5. Acknowledge that the filtration slits of the podocytes are the finest layer, providing the final level of filtration by allowing only the smallest molecules to pass through into the Bowman's capsule.