What are possible consequences of a thrombus?

A thrombus, or blood clot, can impede blood flow in a vessel, which can lead to significant consequences in the affected tissues. One of the primary outcomes of a thrombus is ischemia, which is a reduction in blood supply to tissues. This occurs because the thrombus blocks the vessel, preventing oxygen and nutrients from reaching the downstream tissues. Prolonged ischemia can cause tissue damage and lead to necrosis, where the affected cells die due to lack of blood flow.

Passive hyperemia can also occur as a secondary consequence of a thrombus. When blood flow is obstructed, it may accumulate upstream of the blockage, leading to engorgement of the affected area with blood. This condition is known as passive hyperemia or congestion.

In contrast, other answer choices involve conditions and processes that are less directly related to the actions of a thrombus. For instance, dehydration, infection, and active hyperemia relate to different physiological processes and conditions that do not directly stem from the presence of a thrombus. Understanding these mechanisms is crucial for recognizing the clinical significance of thrombi in cardiovascular health.