What is the term for the dilatation of a vessel wall segment caused by weakness in all three layers?

The term for the dilatation of a vessel wall segment caused by weakness in all three layers is "aneurysm." An aneurysm typically occurs when there is a structural compromise in the vessel wall, which can arise from factors such as hypertension, atherosclerosis, or genetic conditions affecting connective tissue.

In the case of an aneurysm, the weakening leads to an abnormal bulging or outward expansion of the vessel. This dilation can occur in arteries or veins and varies in shape (saccular or fusiform). The weakened vessel wall is particularly susceptible to rupture, which can have serious consequences for blood flow and can lead to life-threatening hemorrhages.

Understanding the conditions that can lead to an aneurysm is critical in the context of vascular health. Recognizing the symptoms and possible complications associated with aneurysms can be crucial for early diagnosis and management. Other terms such as thrombosis, stenosis, and embolism refer to different vascular conditions and do not pertain to the dilatation of a vessel wall segment.