[Biology Class Notes] on Cerebellum Pdf

The cerebellum is a part of the brain of all vertebrates. The brain is the centre holding all necessary connections to all the sensory functions the body responds to. The brain can be considered to be a soft mass of connective tissues which also has nerves connected to the spinal cord that holds and supports the body. The brain controls many bodily functions like talking, walking, feeling, seeing, hearing, ability to think and even controls our breathing as its neural connections are towards other parts of the head as well like eyes, nose, ears etc. It is because our brains facilitate the neuron connections we can stay sane and hold ourselves up, retain information and build relationships. The important parts of the brain are the brain cerebellum, cerebrum and brainstem. Let us further learn about cerebellum and understand what is cerebellum, cerebellum definition and function, cerebellum anatomy and cerebellum structure.

What is Cerebellum?

Cerebellum definition is truly word-based cerebellum comes from a Latin word meaning little brain. It is rightly called the little brain as it is located in the hindbrain below the cerebrum. The cerebrum is that part of the brain which is relatively larger than the cerebellum. The cerebrum cerebellum medulla oblongata is located in alignment connecting to the spinal cord and hence controlling movements. 

Cerebellum Anatomy

Before understanding the cerebellum anatomy, it is important to be familiar with the location of the cerebellum in the human brain, so you can better understand the cerebellum section and its functions. 

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Parts of the Brain 

The cerebellum is developed from the myelencephalon which is the inferior part of the hindbrain. And immediately inferior to the occipital lobe and temporal lobe the cerebellum is located at the back of the brain. The cerebellum is on the same level as the pons and it is separated by the tentorium cerebelli, a tough layer of dura mater by the occipital lobe and temporal lobe. 

Cerebellum Structure

In the cerebellum, there is a narrow midline called the vermis that separates the two hemispheres of the cerebellum. The cerebellum is no different from the other parts of the brain as it is also composed of grey matter which is tightly folded forming the cerebellar cortex is located on the surface and white matter is located just underneath the cerebellar cortex. The white matter of the cerebellum has the dentate, emboliform, globose, and fastigial nuclei which are the four cerebellar nuclei embedded in it. 

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The interior parts of the cerebellum as seen from the image above can be divided into the corpus of the cerebellar that comprises the anterior and posterior lobe in the anterior part and the flocculonodular lobe in the posterior part of the cerebellum. 

1. The anterior lobe that is located above the primary fissure of the cerebellum is responsible for mediating unconscious perception or awareness of the position and movement of the body.

2. The posterior lobe that is located below the primary fissure of the cerebellum plays an important role in motor coordination that includes reflexes along with direct movements. It plays a major role specifically in the inhibition of involuntary movement via inhibitory neurotransmitters, especially GABA (gamma-Aminobutyric acid).

3. The flocculonodular lobe functions are mainly balanced and posture and it is also involved in controlling eye movements because the posterior part of it is connected to the vestibular input via the vestibulo-ocular reflex. If any damage is caused to the flocculonodular lobe of the cerebellum it leads to nystagmus which means rapid involuntary movements of the eyes.

Cerebellum Function 

Three functional parts of the cerebellum play a role in maintaining the balance of the body located in the lateral hemispheres which are the cerebrocerebellum division that sends output to the thalamus and the red nucleus on receiving inputs from the cerebral cortex. This large functional division of the cerebellum plans movements and motor learning. In the intermediate zone of the cerebellar hemisphere, the spinocerebellum is located and it consists mainly of the vermis that regulates body movements and it does so by allowing error correction. In the flocculonodular lobe of the cerebellum, the functional division located is the vestibulocerebellum and as the name suggests it monitors reflexes of eye movements.  The cerebellum based on its position attains the blood supply from the SCA (Superior Cerebellar Artery), AICA (Anterior Inferior cerebellar artery) and PICA (Posterior Inferior Cerebellar Artery).

Did You Know?

1. The youngest region of the brain is considered to be the cerebellum.

2. According to the embryonic development of the brain, the cerebellum is part of the hindbrain and is formed later than other parts of the brain.

3. The human cerebellum is that part of the brain that keeps on changing with age and does so in relevance to the other parts. 

4. The grey matter of the cerebellum contains about 86 million neurons or nerve cells.

5. The cerebellum is considered as the “little brain” and yet makes up eighty-five per cent of the brain’s weight.