Anterior cranial fossa

The anterior cranial fossa is the frontmost part of the cranial cavity. Behind it we have the middle and posterior cranial fossae.

The anterior cranial fossa consists of the frontal, ethmoid, and sphenoid bones. The frontal bone extends forward and to the sides, forming orbital plates that make up the roof of the eye sockets (orbits) and provide support for the frontal lobes of the brain in the cranial cavity.

The ethmoid bone is located centrally and forms the upper part of the nasal cavity. It contains a complex structure called the cribriform plate, which is like a sieve, allowing the olfactory nerves to pass through and enabling our sense of smell.

The frontal bone has a central bony crest called the frontal crest, while the ethmoid bone projects a wedge-shaped bone called the crista galli. These structures provide a strong attachment point for the falx cerebri, a dural partition.

Moving towards the back, the body of the sphenoid bone and its lesser wings create the posterior edge of the anterior cranial fossa. Anatomically, the lesser wings are located where the stem of the lateral sulcus is found in the brain. They also form a distinct border between the anterior and middle cranial fossae, as well as the upper boundary of the superior orbital fissure. Medially, the lesser wing expands and forms the anterior clinoid processes, which extend over the optic canals. These canals allow the passage of the optic nerves and ophthalmic arteries. The processes also serve as attachment points for a dural partition called the tentorium cerebelli. In the middle, the body of the sphenoid bone features a groove known as the suprachiasmatic sulcus, which runs between the two optic canals. Its sharp front edge separates the anterior and middle cranial fossae.