Which of the following best describes the capillary wall structure found in the liver lobules?

• A. Capillaries lined by ciliated epithelial cells
• B. Discontinuous capillaries (sinusoids) with large gaps between endothelial cells
• C. Fenestrated capillaries with small pores but intact basement membrane
• D. Continuous capillaries with tight junctions and no pores

Answer: (B)

Verified step by step guidance

1. Understand the structure and function of capillaries: Capillaries are small blood vessels that facilitate the exchange of substances between blood and tissues. Their structure varies depending on the organ and its specific needs.
2. Learn about the types of capillaries: There are three main types of capillaries: continuous, fenestrated, and discontinuous (sinusoids). Each type has distinct structural features and functions.
3. Focus on discontinuous capillaries (sinusoids): These capillaries are characterized by large gaps between endothelial cells and an incomplete or absent basement membrane. This structure allows for the free exchange of large molecules and cells, which is essential in organs like the liver.
4. Relate the capillary structure to liver function: The liver is involved in detoxification, metabolism, and the production of proteins. Discontinuous capillaries (sinusoids) facilitate the movement of large molecules, such as plasma proteins, and allow for efficient interaction between blood and hepatocytes.
5. Compare the options provided: Evaluate each option based on the structural features of capillaries. Discontinuous capillaries (sinusoids) with large gaps between endothelial cells best describe the capillary wall structure found in liver lobules, as this matches the liver's functional requirements.