What is a vesicle in medical terms?

A vesicle, in medical terminology, refers specifically to a fluid-filled sac that is typically found within tissues. Vesicles are often associated with conditions that involve blisters or contain fluids, such as in the skin or in certain organ systems. They can arise due to a variety of pathological conditions, such as infections or inflammatory responses, and serve as a means of transport for various substances within cells or as a way to isolate and protect cellular materials.

The term encompasses not only physical characteristics but also functional implications within medical contexts, such as the involvement in transporting neurotransmitters in neuronal signaling or in the context of skin lesions. Understanding this definition helps in grasping various medical conditions and their relevance in pathology, therapeutic strategies, and diagnostics.