What term describes the ballooning of a weakened portion of an arterial wall?

The term that describes the ballooning of a weakened portion of an arterial wall is "aneurysm." An aneurysm occurs when a segment of an artery dilates or bulges out due to weakness in the arterial wall. This condition can pose serious health risks, as a ruptured aneurysm can lead to severe internal bleeding and potentially be life-threatening.

In contrast, thrombosis refers to the formation of a blood clot within a blood vessel, which can obstruct blood flow but does not involve the ballooning of an artery. Embolism is related to a blockage caused by a blood clot or other debris that has traveled through the bloodstream, which also does not describe an arterial wall bulge. Stenosis involves the narrowing of blood vessels, which is the opposite of the ballooning described in an aneurysm. Understanding these terms is crucial for recognizing cardiovascular conditions and their implications in medical situations.