Bones of the head (skull): how many are there and what are they called?

The brain is one of the most important organs in the human body, governing the functioning of other bodily systems. Being protected is essential for survival.

Fortunately, we have different protective mechanisms, one of which is a sturdy bone cover that surrounds it. We are talking about the skull, which is made up of different bones.

    Bone protection of the brain: the skull

    When we talk about the skull, we usually imagine the totality of the bones that are part of the head. This consideration is not entirely correct because the skull as such is technically the bony structure that covers the brain. The rest of the bones, like those in the jaw, are part of the facial skeleton.

    however, given its use as a synonym for all the bones of the head we sometimes distinguish the neurocranium, which would be the skull in itself, which protects the brain) and the viscerocráneo (which would include the bony structure that gives shape to the face and of which the bones of the ear include, the nasal cavities, the fossae nasal passages, eye socket, nasal cavity and all the bones that make up the jaw).

    Usually both neurocrani and viscerocráneo are united of solid form, While the boundary between one and the other marks the ear canal and the upper part of the orbit

    The adult human skull, in the sense of neurocranium, it is a set of eight bones welded and assembled throughout development by hardened connective tissue. Its main function is to protect the brain and allow a basic structure in which part of the facial muscles can adhere, as well as to provide a stable position in the blood vessels, cranial nerves and the brain itself. The skull can also be divided into the cranial vault and the base of the skull.

      The bones that make up the skull

      As we have seen, the skull or neurocranium is made up of a total of eight bones brought together and fused throughout the development of the individual for what they call sutures. all they have different openings and holes through which blood vessels and nerves flow.

      Below are the different bones that are part of the skull, along with some of its substructures.

      1. The forehead

      This bone is placed on and protects the frontal lobe. It allows to give shape to the front and arrives until the part superior of the vault of the eye or supraorbital margin, being a point of union between neurocranium and viscerocráneo. It joins the parietal bones by the coronary suture and the nasal bones by the frontonasal suture.

        2. Parietal bones

        This is the biggest bones of the skull, Which form the bulk of the upper and lateral region of it. It connects to the frontal by the coronary suture, to the parietals by the scaly sutures and to the occipital by the lambdoid suture. The two parietals are united by the sagittal suture.

        3. Temporary bones

        Two bones each located under one of the parietals and connected to them by scaly sutures. These irregular bones can be divided into three areas: the scaly which is located around the scaly suture, the mastoid which is the part closest to the jaw in which several muscles of this seat and neck and the stone which is placed in deeper regions, forming part of the base of the skull and having inside it the middle and inner ear. There is also a tympanic region, Which surrounds the ear canal.

        4. The occipital

        This bone mainly forms the base of the skull, placing in it the foramen magnum or orifice in which the brain and spinal cord are connected. It protects part of the occipital and temporal lobe, the cerebellum and the brainstem. It has several protrusions and ridges that connect to the vertebrae. It connects to the parietal through the lambdoid suture and to the temporal through the occipitomastoid.

        5. Sphenoids

        This butterfly or bat shaped bone it is located in an area at the height of the temple, Connection with the frontal, temporal and occipital bones. It runs from side to side of the skull, horizontally, and consists of the body and wings major, minor, and pterygoid processes. In the first is the Turkish chair, a structure that surrounds and protects the pituitary gland. The larger wings are part of the dorsal wall of the eye socket, while the smaller ones are part of the medial part. It keeps the rest of the bones in the skull together and connected.

        6. Ethmoids

        The bone called ethmoid it is located between the sphenoid and the nasal bone, Participating in the formation of the eye sockets and nostrils, playing the role of the roof of the latter (more precisely the part called the sifting sheet) and of the floor of the first, as well as the separation between the two lateral masses of the ethmoid) .

        This bone connects to the meninges through the gallium ridge. It has many cavities called esmoid cells.

        Bones of the viscerocranium

        Although the bones of the skull are correctly the first, it should be borne in mind that other bones exist in the structure of the head beyond them, Those corresponding to the viscerocráneo. In this case, we can find a total of 14 bones, which together with the previous 8 make up the 22 that on average have the head of an adult human (to which it is possible to add those of the ear).

        Below you can see them listed, with each person possessing two of each of the following except the vomer and the jawbone (the latter being the only movable bone structure).

        • jaw
        • maxillary bones
        • nasal bones
        • tear the bones
        • Vomer
        • Bugles
        • Bone Paladins
        • Zygomatic bones (cheekbones)

        In addition to these, in the viscerocráneo we can also find the internal bones of the ear that allow the reverberation of sound until the blister: hammer, anvil and caliper.

        Bibliographical references:

        • Rouviere, H. and Delmas, A. (2005). Human anatomy: descriptive, topographical and functional; 11th ed .; Masson.

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