Anatomy clinical correlates: Skull, face and scalp

The head is one of the most complex parts of our body. Besides having an abundance of muscles, nerves and blood vessels, it protects our brain and houses various facial structures. In this video, we’ll go through a variety of conditions that can affect the skull, face, and scalp. This might not be the easiest subject to learn about, but you’ll see that it’s nothing to get a headache over!

First, let’s discuss the bones of the skull that make up the cranial vault, which as a group are also called the calvaria. We’ll start from the very beginning of their development. See, the flat bones that make up the skulls of neonates have gaps between them and these gaps are covered by fibrous membranes. These membrane-covered gaps between the bones are called fontanelles. The anterior fontanelle is a large diamond-shaped area found at the junction of the sagittal suture, coronal sutures and frontal suture.

In adults, this point where the sutures eventually come together is called the bregma. The anterior fontanelle is bordered by the frontal bone anteriorly and two parietal bones posteriorly. By 18 months of age, the bones fuse together and the anterior fontanelle closes. The posterior fontanelle is a triangular shaped membrane found at the junction of the lambdoid sutures and sagittal suture. In adults, this point is called the lambda. The posterior fontanelle is bordered by the two parietal bones anteriorly and the occipital bone posteriorly. The posterior fontanelle usually closes during the first few months of life and is no longer palpable by the end of the first year.

By palpating fontanelles before they close, bone growth and development of the skull can be assessed. How fontanelles look is also important from a clinical standpoint. For example, a depressed fontanelle can indicate dehydration, while a bulging fontanelle can signal increased intracranial pressure.

Now, let’s move on to bone fractures, and to start let's remember an intersection of the skull called the pterion. This is where the frontal, parietal, temporal, and sphenoid bones meet. Now, immediately deep to the pterion is a branch of the maxillary artery called the middle meningeal artery and its branches. So if an individual receives a hard blow to the area of the pterion; this can then fracture these bones right at that weak spot where they all meet. The fracture can then damage the middle meningeal artery, causing significant intracranial bleeding.