The human skull contains numerous openings that are known as foramina (sing. foramen), hiatuses (sing. hiatus), canals, canaliculi (sing. canaliculus), apertures, and fissures. These openings serve as crucial passageways that allow the transmission of various nerves, blood vessels, and other structures between the internal and external structures of the head and neck.

All these openings are strategically located throughout different regions of the skull, including the orbits, temporal, pterygopalatine, infratemporal, and cranial fossae, as well as the nasal cavity. Understanding the locations and structures transmitted by each opening is fundamental for comprehending the complex anatomy and physiology of the head and neck.