Hey, everyone! It’s Matt from Kenhub, and in this tutorial, we will discuss the temporal bone.
The temporal bone is a large bilaterally symmetrical bone which forms the base of the cranial vault along with the occipital bone, in the sense, to participate in the lateral walls of the skull. It is divided into four parts – the squamous part, the tympanic part, the styloid process and the petrous part.
The squamous part is a flat plate that builds the lateral wall of the middle cranial fossa. It houses the middle meningeal artery that is marked by a grove in the bone. The zygomatic process arises from the outer surface of the squamous part and articulates with the zygomatic bone. The glenoid fossa sits just below the zygomatic process where it comes into contact with the mandibular condyle. It is part of the temporomandibular joint. The squamous part is separated from the tympanic part by the petrous part. The petrotympanic fissure lies behind this division.
The tympanic part is horseshoe-shaped and contributes to the anterior, posterior and inferior walls of the external acoustic meatus and the posterior, non-articulating part of the glenoid fossa. Laterally, it is attached to the cartilage of the external acoustic meatus and, medially, to the tympanic membrane, also known as the temporal sulcus.
The styloid process is a spike-like projection from the inferior aspect of the temporal bone. It arises just anteriorly to the stylomastoid foramen which harbors the facial nerve and the stylomastoid artery.
The petrous part is the pyramid-shaped medial part of the temporal bone and separates the middle and posterior cranial fossae. It is extremely solid and protects the anterior auditory and vestibular apparatus.
The internal acoustic meatus is located at the posterior surface leading to the ear canal. The inferior surface contains numerous openings such as the carotid canal and the jugular foramen. The most posterior part of the petrous portion contains the mastoid process which is filled with mastoid air cells and lined with mucous membrane inside.
The squamosal suture connects the temporal and parietal bone and continues as the sphenosquamosal suture anteriorly and the parietomastoid suture posteriorly. The occipitomastoid suture runs between the mastoid part of temporal bone and the occipital bone. The zygomatic process articulates with the temporal bone through the temporozygomatic suture.