Final answer:
An anastomosis is the correct answer; it's a connection between vessels that allows blood circulation even with partial blockage elsewhere.
Step-by-step explanation:
A new connection between two previously unconnected tubes is called an anastomosis. An anastomosis (plural = anastomoses) is an area where vessels unite, enabling blood to circulate even if there may be partial blockage in another branch. In the context of the circulatory system, an example of this would be an arteriovenous anastomosis, which is a short vessel connecting an arteriole directly to a venule, bypassing the capillary beds. This physiological process is essential because it provides an alternative pathway for blood to reach body tissues in the case of a blockage. Although these anastomoses exist in the body, such as in the heart, they might be small, making the heart vulnerable to serious consequences like myocardial infarction if coronary artery blockage occurs.