When Was the Brain Created?

This article will answer the question “When was the brain created?” It also covers what the human brain is composed of and the functions of each of the parts of the brain. In the end, the article addresses some frequently asked questions.

When Was the Brain Created?

Fossilization of the brain or other soft tissue of the brain is possible. Scientists can infer, from this data accumulated, that the first brain structure appeared 521 million years ago (Park et al., 2018).

Before the complex evolutionary development of the brain, the simplest form of the nervous system developed in our long-long ancestors. These were known as nerve nets. These nerve nets served as a precursor for the development of more advanced brains. 

These nerve nets were first observed in Cnidaria and are composed of several neurons that spread out so that they can enable the organism to react or interact with physical contact.

Nerve nets were able to perform rudimentary tasks such as detecting food. However, the nerve nets did not help them detect or find out the source of the stimulus.

Today, however, our body has the richest network of blood vessels that nourish our bodies. When our brain is involved in complex thought processes, it can use upto 50% of the body’s oxygen and fats. In fact, our arteries carry 20-25% of the blood to the brain alone. The entire blood vessel netrowk is composed of capillaries and veins along with the arteries. Thus, around 20% of the body’s calories and oxygen is used by the billion cells comprising our brain.

What are the Brain Structures in the Human Brain?

The brain is classified into three main parts or areas of the brain:

Cerebrum: 

This is the front part of the brain composed of the grey matter- the cerebral cortex and white matter at the centre. The cerebrum is the largest part of the brain, this part is responsible for the regulation of the temperature of the body as well as for coordinating movements of the body. 

The cerebrum enables thinking, reasoning, problem-solving, speech, judgement, learning and regulating emotions. There are other functions of the brain, and these are related to vision, touch and hearing. 

Cerebral Cortex

The cortex is come from the Latin word “bark” and is used to describe the outer grey matter that covers the cerebrum. This part has a larger surface, this is because this area has folds and comprises half of the brain weight.  One region of the cortex is covered by ridges (gyri) and other folds (sulci). 

These two parts join at the deep large sulcus, this is the interhemispheric fissure, AKA the medial longitudinal fissure that runs from the front part of the head to the back part. The left hemisphere of the brain controls the right side of the body, and the right hemisphere controls the left side of the body. 

These two halves of the brain communicate through a C- type large structure known as the corpus callosum. This is located in the centre of the cerebrum. The corpus callosum comprises nerve pathways and white matter. 

Brainstem

This connects the cerebrum with the spinal cord and forms the middle part of the brain. The brainstem comprises the midbrain, pons and medulla. 

Midbrain

The midbrain (or mesencephalon), has a range of different neuron clusters (nuclei and colliculi) is a very complex structure and has several neural pathways and other structures. The midbrain coordinates various functions, these functions range from hearing and movement, they also help in calculating different responses and changes in the environment.

The midbrain also contains the substantia nigra, this part is affected by Parkinson’s disease. This part is rich in dopamine neurons and also is part of the basal ganglia, this part of the brain helps in enabling movement and coordination.

Pons

The pons is derived from the Latin word “bridge”. Pons connect the midbrain and the medulla. These are the origin of four of the 12 cranial nerves, these help enable a range of activities such as tear production, chewing, blinking, focusing vision, balance, hearing and facial expression. 

Medulla

This is located at the bottom of the brainstem, the medulla is where the brain meets the spinal cord. This plays an important role in survival. The medulla helps produce reflexive activities such as sneezing, vomiting, coughing and swallowing. 

The medulla has other important functions such as regulating many bodily activities, including heart rhythm, breathing, blood flow, and oxygen and carbon dioxide levels.

The spinal cord extends itself from the bottom part of the medulla through the large opening in the skull. The spinal cord carries important messages from the brain to the rest of the body, through the vertebrae. 

Cerebellum

The cerebellum is also known as the (“little brain”) and is a fist-sized portion of the brain. The cerebellum just like the cerebral cortex has two hemispheres. The outer portion contains neurons, and the inner area communicates with the cerebral cortex. This has two hemispheres, the inner part communicates with the cerebral cortex, whereas the outer part contains neurons. 

The function of the cerebellum is to help coordinate voluntary muscle movements, balance, posture and maintain equilibrium  (Strick et al., 2009). Several recent studies are understanding the possible involvement in addiction, autism and schizophrenia. Studies are also exploring the role of the cerebellum in regulating thoughts, emotions and social behaviour. 

What is the grey matter and white matter?

The central nervous system is comprised of two different brain regions. The Gray matter and the white matter. In brain regions, the grey matter is the darker, outer region of the brain, while the white matter is the inner lighter region of the brain. 

However, in the spinal cord, the order is opposite this. In the spinal cord, the grey matter is the inner region and the white matter is the outer region of the brain. 

In the brain, the grey matter is composed of something known as somas, which are the central round cell bodies, whereas the white matter is made of long stems known as axons, which are responsible for connecting different neurons to one another. 

Axons are wrapped in myelin which is the protective coating. Under certain scans, the different compositions of neurons clearly distinguish the two as separate shades. 

Weight of the human brain

The weight of the human brain is about 3 lbs or 1.4 kilograms. It makes up around 2% of the human body weight. The male brains are found to be roughly 10% larger than female brains according to a study done by Northwestern Medicine in Illinois. 

The male brain has a brain volume of 78 cubic inches or 1,274 cubic centimetres on average as compared to the female brain which has a volume of 69 cubic inches or 1,131 cubic centimetres. The cerebrum is considered to be the main part of the brain and it is located in the front area of the skull. The cerebrum makes up around 85% of the brain’s weight (Im et al., 2008).

Conclusion 

This article answers the question “When was the brain created?” It also covers what the human brain is composed of and the functions of each of the parts of the brain. In the end, the article addresses some frequently asked questions.

Frequently Asked Questions: When Was the Brain Created?

What makes up 80% of the human brain?

The cerebral cortex makes up about 80% of the brain’s space or total volume. This is interesting because the cerebral cortex is a relatively recent development in humans when compared to the evolutionary history of the human brain (Ackerman, 1992).

Can your brain get tired of thinking?

Yes, the brain can get burnt out by thinking. This phenomenon is known as brain fog or mental fatigue. When the brain is overstimulated it can cause dysfunctions in cognitive abilities, and affect one’s productivity, decision-making and problem-solving skills, as well as memory. It can also make it difficult for one to concentrate on daily mundane tasks.

Is the brain capable of healing itself?

Yes. In fact, the process known as neuroplasticity plays an important role in carrying out the function and making the brain resilient. The brain repairs itself through the process of neuroplasticity. 

References 

Park TS, Kihm JH, Woo J, Park C, Lee WY, Smith MP, et al. (March 2018). “Brain and eyes of Kerygmachela reveal protocerebral ancestry of the panarthropod head”. Nature Communications. 9 (1): 1019. Bibcode:2018NatCo…9.1019P. doi:10.1038/s41467-018-03464-w. PMC 5844904. PMID 29523785.

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