Sinusoids are a type of capillary characterized by ________.

Sinusoids are a type of capillary characterized by ________.

• A. Small lumens and tight junctions
• B. Continuous endothelium and complete basal lamina
• C. Enlarged lumen and discontinuous basal lamina
• D. Low permeability and high resistance

Answer: (C)

Sinusoids are a specialized capillary type that have an enlarged, irregular lumen and a discontinuous basal lamina. This combination creates a highly permeable pathway, allowing larger molecules and even blood cells to pass between blood and surrounding tissues. The endothelium is also often discontinuous, contributing to this increased permeability. In contrast, continuous capillaries have small lumens with tight junctions and a complete basal lamina, making them less permeable. So the hallmark features—enlarged lumen and discontinuous basal lamina—best describe sinusoids.

Sinusoids are a specialized capillary type that have an enlarged, irregular lumen and a discontinuous basal lamina. This combination creates a highly permeable pathway, allowing larger molecules and even blood cells to pass between blood and surrounding tissues. The endothelium is also often discontinuous, contributing to this increased permeability. In contrast, continuous capillaries have small lumens with tight junctions and a complete basal lamina, making them less permeable. So the hallmark features—enlarged lumen and discontinuous basal lamina—best describe sinusoids.