The space within the cranium is the cranial cavity whose floor is divided into the anterior, middle and posterior cranial fossa, a high to low three-tiered structure. The cranial fossa is made up of several bones that contribute to the skull base and contain several foramina through which structures enter and exit. This is summarised as follows: Cranial fossa Contributing bones Foramina Contents Anterior (highest) frontal, … Continue reading Cranial fossae

The paired parietal bones lie on both sides of the superior portion of the cranium. They contain foramina for emissary veins that connect scalp veins with the venous dural sinuses inside the skull. Continue reading Parietal bones

The frontal bone forms the bony part of the forehead and is divided at birth (the two parts fuse in early life). The paired frontal sinuses (a paranasal sinus) behind the brow drain into the middle meatus of the nose via the frontonasal duct. Landmarks include the superciliary arch (supraorbital/brow ridge) and supraorbital foramen (notch, if incomplete) through which passes the supraorbital nerve (a branch … Continue reading Frontal bone

Each temporal bone is divided into squamous, petromastoid and tympanic parts as well as the styloid process. They mainly contribute to the lateral aspects of the middle cranial fossa and cup the temporal lobes of the brain. Squamous part: the flat superior portion, includes the zygomatic process (joins the zygomatic bones temporal process to form the zygomatic arch) and mandibular fossa (articulates with mandible via … Continue reading Temporal bones