The bone that protects your brain (what is it?)

Humans are capable of living without some of our organs. We can have a perfectly normal life with only one kidney, without reproductive organs, without a spleen and even, if a cancer situation requires it, without a stomach.

What is physically impossible is living without a brain, so it is not surprising that evolution has led us to protect this structure in the safest way that anatomy allows.

In this post we are going to talk about the bones that protect our brains, how they are constituted, we will detail its parts and highlight the importance of this protective bone for the human being.

What is the Bone that protects your brain?

The skull is the bone that protects your brain.

Bones are rigid organs that, in addition to making movement possible and allowing the body to be properly supported, have the mission of protecting sensitive organs. That is why our brain is surrounded by a series of bones with different morphology and functionality that fulfill the purpose of protecting the store of all our information, our perception and our cognition.

Anyway, the role of the human head is not limited only to the protection of the brain, but it is also the place where most of our senses reside and the one that gives us individual personality. That is why a total of 22 bones fulfill these and many other functions, guaranteeing correct morphology and physiology.

In this article we will see what are the bones that make up our head, paying special attention to the functions they perform and their biological purpose.

Is “head” the same as “skull”?

Traditionally we tend to refer to the head and the skull as simple synonyms. However, technically they are not, as the skull is a portion of the head. The term skull refers to the bony structures that cover and protect the brain, forming part of a “whole” that is the head.

This, therefore, includes both these skull bones and the rest of the elements that make up the facial skeleton: mouth, eyes, jaw, nose, etc.

In this context, the classification of the bones of the head is carried out according to this differentiation. On the one hand, we have a group of neurocranial bones: flattened bony elements that surround the brain, protecting it.

On the other hand, we have the group of the viscerocranium: bones of much more variable shapes that accompany and make possible much broader biological functions (smell, speech, vision, food, etc.).

Therefore, in this article we will differentiate between the bones of the neurocranium and the viscerocranium, reviewing the bones that make up each of these groups.

Neurocranial bones: brain protection

A total of eight bones flattened and naturally welded together form the structure that protects the brain from blows and injuries, thus ensuring that the nervous system does not suffer damage throughout the life of the person.

We have heard it said many times that babies cannot hit their heads because they don’t have bones yet. This, despite the fact that you always have to watch out for the little ones, is not entirely true.

At the moment we are born we already have these skull bones; the problem is that, due to the disproportionate size of the brain in relation to the other organs at birth, these bones are not well welded together. As childhood progresses, these “holes” disappear, thus forming a compact structure.

Next we will see one by one these bones of the neurocranium: two temporal bones, two parietal bones and one frontal, occipital, ethmoid and sphenoid.

1. The frontal bone

The frontal bone is the one that is located in the forehead. It begins just above the eye sockets and ends at the top of the forehead, thus being the connecting link between the bones of the skull and those of the viscerocranium.

Its main function, in addition to shaping the forehead, is to protect the frontal lobes of the brain, which are located just behind this bone. Protecting these lobes ensures that executive functions such as mental flexibility, attention and memory are not susceptible to trauma.

2. The two temporal bones

These two bones are located on the sides, one on each side of the head. These two bones protect the temporal lobes, thus ensuring that auditory language and speech understanding are not susceptible to trauma.

They also protect the brainstem, which is the major communication pathway for the brain, spinal cord, and peripheral nerves. The temporal bones are therefore responsible for ensuring that the area responsible for controlling respiration and heart rate is not affected.

These two bones have a hole that serves to support the ear, thus allowing sounds to reach the eardrum on each side of the head. Otherwise, we could not perceive any sound.

3. The occipital bone

The occipital bone is a markedly concave bony element located at the nape. Its function is to protect, again, the brain stem. In addition, it also ensures the integrity of the cerebellum and occipital lobes, responsible for muscle coordination and processing the images we perceive, respectively.

4. The two parietal bones

The two parietal bones occupy the area that makes up the crown and its surroundings. They are two symmetrical bones and welded together.

Its function is to protect the part of the cerebral cortex underneath, which is where perception, imagination, judgment, thought, etc. occur. In the same way, it ensures the integrity of the parietal lobes and the subcortical organs underneath. These parietal lobes are responsible for regulating moods and processing sensory stimuli.

5. The ethmoid bone

The ethmoid bone is the only one of this group that does not have a flattened shape. In fact, its morphology is rough and with cavities. It is not an “external” bone, as it is located on the inside of the face, behind the nose.

Its function is to be the main supporting structure of the nasal cavity, thus developing a primary mission for the proper functioning of the olfactory system, creating channels through which air can flow.

6. The sphenoid bone

The sphenoid bone could be considered as the cornerstone of the base of the skull, since it is the one that allows, being located in the middle portion of the base of the skull, other bony elements of the skull to be joined together.

Its function, therefore, is to support other bones of the skull and also to shape the internal structure of the face.

Bones of the viscerocranium: multiple functions

As we have already mentioned above, now we are going to review what are the rest of the bones that make up the human head and their functions, functions that, as we will see, are very varied and are not limited to the mere protection of sensitive organs.

1. The maxillary bone

The maxillary bone is a bone of irregular morphology that occupies the central part of the face, from the upper part of the mouth to the base of the nostrils.

Its main function is to support the upper teeth, including the roots of these teeth. It also serves as a support for other bones of the viscerocranium.

2. The palatine bone

The palatine bone is a continuation of the maxilla and it is the one that penetrates deeper with respect to the surface of the face. In addition to supporting other bone elements, it also serves as a support for internal tissues. It is L-shaped and forms the roof of the mouth.

3. The nasal bones

The two nasal bones are small bony elements attached to each other and located in the middle of the face. They form the nasal septum, thus protecting the nose and housing cartilage in its distal part.

4. The tear bones

The lacrimal bones are small bony structures located just behind the jawbone. These are bones located in each eye socket and have the function of participating in the tear function, that is, providing a path for the tears of the eye to be led to the nasal cavity.

5. The vomer bone

The vomer bone is a bone located behind the maxilla, just below the nose and consisting of a thin vertical sheet that helps in the formation of the nasal septum.

6. The inferior nasal concha

The inferior nasal shell or inferior turbinate is a bony structure located just behind the nostrils. Its spongy consistency allows it to support tissues covered with nasal mucosa and blood vessels and, at the same time, allow the constant entry of air into the nasal cavity.

7. The zygomatic bone

The zygomatic bone has a rhomboid shape that is located in the lower lateral part of the eye sockets, thus forming the cheekbones. It is an insertion point for various facial muscles responsible for chewing and also participates in sustaining the eyes.

8. The jaw

The jaw is the only bone in the head with mobility. It consists of a base and two mandibular branches attached to the temporal bone for fixation. In addition to being the base of the lower teeth, the jaw makes possible basic functions of our body such as speech and chewing.

Bone malformations

The skull is also susceptible to diseases, malformations and genetic defects. Crouzon’s disease or craniosynostosis, is due to a genetic mutation that causes the sutures of the fontanelles to close early. This causes deformation of the skull and face, and in some cases, hydrocephalus.

Paget’s disease causes inflammation of the bone tissue and this can lead to fractures and deformations. Other ailments that can affect the development of the skull are microcephaly, hydrocephalus, spina bifida and some cases of meningitis and encephalitis.

The skull is therefore the protective element of the most precious organ of the human being: the brain. It also helps to give structure to the face, with its unique and characteristic features. And along with the rest of the skeleton, it is what lasts the longest after death.

FAQS: Bone that protects your brain

Which bone protects the brain from damage?

The skull protects the brain and forms the structure of the face.

What type of bone protects the brain?

The skull is located before the vertebral column and is a bony structure that encloses the brain.

What portion of the skull protects the brain?

Neurocranium: The part of the skull that encloses and protects the brain and brain stem.

What part of the brain does the occipital bone protect?

The occipital bone is a markedly concave bony element located at the nape. Its function is to protect, again, the brain stem.

How is brain protected in our body?

The brain and spinal cord are covered and protected by three layers of tissue (membranes) called the meninges.

In this post we talked about the bones that protect our brains, how they are constituted, we will detail its parts and highlighted the importance of this protective bone for the human being.

References

Angela, B. (2014) Functional anatomy of the skull. Republic of Moldova: State University of Medicine and Pharmacy “Nicolae Testemitanu”.

Hiatt, J.L., Gartner, L.P. (2010) Textbook of Head and Neck Anatomy. Maryland (EU): University of Maryland, Department of Biomedical Sciences.

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