Which statement correctly distinguishes an embolus from a thrombus?

Which statement correctly distinguishes an embolus from a thrombus?

• A. An embolus travels through the bloodstream; a thrombus is stationary.
• B. Both emboli and thrombi travel to the lungs.
• C. A thrombus travels while an embolus is stationary.
• D. They are both infections.

Answer: (A)

Think about how clots form and move in the bloodstream. A thrombus is a clot that forms on the wall of a vessel and tends to stay there at the site of formation unless something dislodges it. An embolus, on the other hand, is any material that travels through the bloodstream once it’s dislodged from its origin, and it can lodge far away from where it formed. That’s why the statement that an embolus travels through the bloodstream while a thrombus is stationary best captures the distinction. It reflects the idea that emboli are mobile and can cause distant blockages, whereas thrombi stay put at their formation site. The other options misstate this: thrombi don’t automatically travel, emboli aren’t necessarily infections, and a thrombus traveling while an embolus is stationary is the reverse of the true relationship.

Think about how clots form and move in the bloodstream. A thrombus is a clot that forms on the wall of a vessel and tends to stay there at the site of formation unless something dislodges it. An embolus, on the other hand, is any material that travels through the bloodstream once it’s dislodged from its origin, and it can lodge far away from where it formed.

That’s why the statement that an embolus travels through the bloodstream while a thrombus is stationary best captures the distinction. It reflects the idea that emboli are mobile and can cause distant blockages, whereas thrombi stay put at their formation site. The other options misstate this: thrombi don’t automatically travel, emboli aren’t necessarily infections, and a thrombus traveling while an embolus is stationary is the reverse of the true relationship.