What is an example of a vesicle?

A blister serves as a prime example of a vesicle because it is defined as a small, fluid-filled sac that forms on the skin's surface, typically in response to friction, burning, or other injuries. Vesicles are characterized by their size and the fluid they contain, which is often serous (clear or straw-colored).

In this case, a blister’s formation involves the separation of the upper layers of skin, allowing fluid to accumulate in the space, which is precisely how vesicles are formed. This distinct trait is what categorizes blisters within the broader classification of vesicular lesions.

Other options, like fever blisters, while also displaying vesicular characteristics, are specifically herpes simplex lesions that can appear on the lips or mouth and may differ in context. Pressure sores, on the other hand, are ulcers resulting from prolonged pressure and do not exhibit the same fluid-filled sac structure as vesicles, and warts are benign growths caused by the human papillomavirus and do not correspond to the definition of a vesicle. Thus, a blister stands out as the textbook definition of a vesicle.