A house of the soul, a seat of power, and a commemoration of the dead; the skull has always had a great symbolic status across many cultures in history. In modern days, whenever we think of students in the medical field, an image of a person holding a skull and a giant anatomy textbook instantly pops up in our minds.
With its complex structure that has over sixty foramina and over twenty bones, the skull can be one of the most challenging yet fun human anatomy topics to study. This article will serve as a study guide to help you understand how to approach the external anatomy of the skull. Let’s get started!
Overview of the bones
The human skull is the skeletal structure of the head consists of between 22 to 30 single bones which are mostly connected together by ossified joints, so-called sutures. It is subdivided into the facial bones (facial skeleton) and the braincase (cranial vault or cerebral cranium). The facial skeleton protects and supports the underlying facial structures, and encloses the eyeballs, whilst the cranial vault houses the brain, as well as the middle and inner ear structures.
Neurocranium: occipital bone, temporal bones (2), parietal bones (2), sphenoid bone, ethmoid bone, frontal bone
Viscerocranium: vomer, nasal conchae (2), nasal bones (2), maxilla, mandible, palatine bones (2), zygomatic bones (2), lacrimal bones
(1) Region of the cranium, subregions:
- cranial vault - upper portion of the skull
- cranial base - inferior portion of the skull
- cranial cavity - interior of the skull (subregions: anterior, middle, posterior cranial fossae)
- facial skeleton - bones that make up the face
- acoustic skeleton - ear ossicles
(2) Region of the mandible
|Clinical relations||Fractures, osteoporosis, osteoradionecrosis, osteomalacia, osteomyelitis, pneumatization, circumstantial bone resorption|
Watch this video to master the bones of the skull!
Anterior (frontal) view
The frontal bone is found superiorly while the mandible lies inferiorly, giving the skull an ovoid shape when looked at anteriorly. The frontal bone underlies the forehead; above the orbital cavities, the nasal bridge (which is formed jointly by the two nasal bones), and the frontal process of the zygomatic bone.
The two maxillary bones (maxillae) occupy most of the space in the middle part of the facial skeleton. Together with the nasal bones, they form the boundaries of the anterior nasal aperture. Inferiorly, the mandible and the alveolar processes of the maxillary bones form the lower part of the anterior skull.
If this sounds like a lot to handle, we have you covered with our comprehensive video tutorial.
Further, read our detailed article, and take our interactive quiz.
Lateral (side) view
The lateral aspect of the skull can be divided into three regions:
- The face
- The temporal region, which we will cover in detail in this section.
- The occipital region
The temporal region is subdivided by the zygomatic arch into the temporal fossa and the infratemporal fossa. The frontal bone, the parietal bone, the greater wing of the sphenoid bone, and the squamous part of the temporal bone meet at the pterion, forming the floor of the temporal fossa. The following videos, articles, and quizzes will cover everything you need to know about the temporal region of the skull, so make sure to check them out!
The posterior aspect of the skull is formed by the parietal bone superolaterally, the temporal bone inferolateral, and the occipital bone centrally. Sometimes this view of the skull is referred to as the occipital view.
From above, we can see the ellipsoid-shaped part of the skull called the calvaria. It is formed by four bones; the frontal bone, the two parietal bones, and the occipital bone. These bones articulate through three sutures:
- The coronal suture: between the frontal and parietal bones.
- The lambdoid suture: between the occipital and parietal bones.
- The sagittal suture: between the two parietal bones.
To better understand the anatomy of this region, don’t forget to watch our corresponding video tutorial, read our articles, and further strengthen your knowledge with our quiz.
Base of the skull (inferior view)
The base of the skull extends from the superior nuchal lines of the occipital bones posteriorly to the upper incisors teeth anteriorly. This aspect of the skull contains a lot of important structures, including the largest skull foramen; the foramen magnum. We can divide this part of the skull into five, to make it easier to study:
- Anterior part: the hard palate and the upper jaw.
- Middle part: the sphenoid bone, petrous processes of the temporal bones, and the basilar part of the occipital bone.
- Lateral parts: the zygomatic arches, mandibular fossae, tympanic plates and the styloid and mastoid processes.
- Posterior part: the occipital bone.
Learn all the parts of the skull with our video and bones of the skull quiz (inferior view).
Skull anatomy quizzes