An opening which allows blood vessels to pass into an organ.
Opening or entry, especially one through which blood vessels pass into an organ (e.g., porta hepatis, the opening through which major blood vessels enter and leave the liver).
The aperture in an organ through which its associated vessels pass. Such an opening occurs in the liver (porta hepatis).
The point of entry of nerves and vessels into an organ or part.
The section of an organ through which nerves and blood vessels traverse, also known as the hilum.