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 the rest of the body’s systems. That it is protected is essential for survival.
Fortunately, we have different protection mechanisms, one of which is a strong bony covering that surrounds it. We are talking about the skull, which is made up of different bones
When talking about the skull, we usually imagine all the bones that make up the head. This consideration is not entirely correct, since The skull itself is technically the bony structure that covers the brain The rest of the bones, such as those of the jaw, are part of the facial skeleton.
However, given its use as a synonym for the set of bones of the head Sometimes a distinction is made between the neurocranium, which would be the skull itself, which protects the brain) and the viscerocranium (which would include the bone structure that gives shape to the face and of which the bones of the ear, the nasal passages, the eye socket, nasal cavity and the set of bones that make up the jaw).
In general both neurocranium and viscerocranium are solidly united considering that the border between one and the other is marked by the ear canal and the upper part of the eye socket
The adult human skull, in its meaning as a neurocranium, It is a set of eight bones welded and joined together throughout development through hardened connective tissue. Its main function is to protect the brain and allow a basic structure to which part of the facial muscles can adhere, in addition to providing a stable position for the blood vessels, cranial nerves and the brain itself. Likewise, the skull can be divided into cranial vault and skull base.
Bones that make up the skull
As we have seen, the skull or neurocranium is made up of a total of eight bones joined together and welded throughout the development of the individual in what are called sutures. All of them They have different openings and holes through which blood vessels and nerves circulate
Below are the different bones that make up the skull, as well as some of its substructures.
1. Frontal bone
This bone sits above and protects the frontal lobe It allows the forehead to be shaped and reaches the upper part of the vault of the eye or supraorbital margin, being a meeting point between the neurocranium and viscerocranium. It joins with the parietal bones by the coronary suture, and with the nasal bones by the frontonasal suture.
2. Parietal bones
Is about the largest bones of the skull, which form most of the upper and lateral region of this. It is connected to the frontal by the coronary suture, to the parietal by the squamous sutures, and to the occipital by the lambdoid suture. Both parietal bones are joined together by the sagittal suture.
Two bones, each located under one of the parietal bones and joined to them by squamous sutures. These irregular bones can be divided into three areas: the squamous, which is located around the squamous suture, the mastoid, which refers to the part closest to the jaw in which several jaw and neck muscles sit. and the stone that is located in deeper regions, forming part of the base of the skull and having the middle and inner ear inside. There is also a tympanic region which surrounds the ear canal.
4. Occipital bone
This bone mainly makes up the base of the skull, the foramen magnum being located in it or hole in which the brain and spinal cord connect. It protects part of the occipital and temporal lobe, the cerebellum and the brain stem. It has several protuberances and ridges that connect with the vertebrae. It is connected to the parietal by the lambdoid suture and to the temporal by the occipitomastoid suture.
5. Sphenoid
This bone shaped like a butterfly or bat It is located in an area at the height of the temple, connecting with the frontal, temporal and occipital bones. It goes from side to side of the skull, horizontally, and is made up of the body and greater and lesser wings and pterygoid process. In the first you can find the sella turcica, a structure that surrounds and protects the pituitary gland. The greater wings are part of the dorsal wall of the eye orbit, while the lesser wings are part of the medial part. It keeps the rest of the bones of the skull together and connected.
The bone known as the ethmoid It is located between the sphenoid and the nasal bone participating in the formation of the eye orbits and the nostrils, acting as the roof of the latter (specifically the part called the cribriform plate) and the floor of the former, as well as a separation between the two (the lateral masses are responsible for this of the ethmoid).
This bone connects with the meninges through the crista galli. It has numerous cavities called esmoid cells
Bones of the viscerocranium
Although the bones of the skull are actually the previous ones, it must be taken into account that There are other bones in the structure of the head beyond them, those corresponding to the viscerocranium. In this case we can find a total of 14 bones, which together with the previous 8 make up the 22 that the average adult human head has (to which it is possible to add those of the ear).
Below you can see them listed, each person having two of each of the following except the vomer and the mandible (the latter being the only movable bone structure).
In addition to these, within the viscerocranium we can also find the internal ear ossicles that allow the reverberation of sound until clucking: hammer, anvil and stirrup
