Educational Content: This article is for informational purposes only and does not constitute medical advice. Always consult a healthcare provider for diagnosis and treatment.
Definition of Pinosome
Medically reviewed by Min Clinic Staff | Updated: January 2026
Pinosome: A tiny fluid-filled vesicle (bubble) within a cell.
Pinosomes are created in the process of pinocytosis in which tiny incuppings called caveolae (little caves) in the surface of the cell close and then pinch off to form pinosomes within the cytoplasm of the cell.
Pinocytosis permits the active transport of fluid through the membrane surrounding the cell into the interior of the cell.
The word "pinosome" stemmed from Greek roots: pinein, to drink + soma, body = a drinking body.