Skull

The term skull includes all the bones making up the head. This comprises the bones which enclose the brain-i.e., the cranium, and the bones composing the skeleton of the face.

Cranium

The bones of the cranium are - The occipital, sphenoid, ethmoid, frontal, the two parietals, and the two temporals.

Face

The bones of the face are - The vomer, the mandible, and pairs of maxillae, malar, palate, lachrymal, nasal, and inferior turbinate.

The hyoid bone is usually described with those of the skull.

All the bones of the head and face are joined together by immovable joints (sutures), except the mandible.

The skull, as a whole, is studied from five aspects-from the front, the side, the back, the top, and the base.

Norma Frontalis - the skull viewed from the front.

This is limited above by the smooth convex upper part of the frontal bone, and below by the teeth of the upper jaw, if the mandible be disarticulated. The eye-sockets are formed by the lower part of the frontal bone, which in the middle articulates with the two nasal bones to form the bridge of the nose. The lower border of the eye-sockets is formed, internally, by the maxillae and externally, by the malar bones, which give prominence to the cheeks. The two maxillae articulate in the middle line below the nasal opening, to form the upper jaw; below hangs the mandible, or lower jaw, which articulates on each side by a very loose joint with the temporal bone.

Norma Lateralis (The Side View Of The Skull)

In this view it can be seen distinctly which bones form the face and which the cranium. A line drawn from the middle of the lower border of the frontal bone to the mastoid process of the temporal bone indicates the boundary. The cranium is of oval shape, with the long axis going backwards and downwards. The bones composing it from before backwards, are - The frontal, parietal, temporal, and occipital. In this view it can also be seen that the malar articulates with a process of the temporal. Between this process and the opening of the ear is the articulation of the mandible.

Fig. 38. - The Lateral Region of the Skull (Norma Lateralis).

I, I, Frontal; II, II, Parietal ; III, Occipital ; IV, Great Wing of Sphenoid ; V, Squamous Portion of Temporal; VI, Mastoid Portion of Temporal ; VII, Zygoma ; VIII, Malar ; IX, Nasal; X, Superior Maxilla (Nasal Process); XI, Lachrymal; XII, Ethmoid (Os Planum) ; XIII, Inferior Maxilla.

1, Bregma; 2, Superior Temporal Ridge ; 3, Inferior Temporal Ridge ; 4, Occipital Point; 5, Auricular Point; 6, Mental Foramen ; 7, Lachrymal Groove ; 8, Glabella.

Occipitalis (the back view of the skull) shows the rounded shape of the back of the head and the joints of the occipital and parietal bones, called the lambdoid suture.