Final answer:
The term for erythrocytes traveling in single file through capillaries is not provided, but this process is part of the efficient gas exchange mechanism in microcirculation within capillary beds.
Step-by-step explanation:
The term for erythrocytes traveling in single file through the narrow diameter of capillaries is not explicitly provided in the material, but this process relates to the capillary's role in microcirculation. Erythrocytes, or red blood cells, are biconcave disks that provide a large surface area for gas exchange. In the narrow capillary beds, the slow passage of erythrocytes allows for extended opportunities for gas exchange. Additionally, the flexible protein spectrin in erythrocytes enables them to bend and pass through these narrow vessels. When in larger vessels, erythrocytes can stack to form a rouleaux, which look like a roll of coins. The phenomenon of erythrocytes traveling in single file is crucial for efficient gas exchange in capillaries.