Difference Between Cerebellum and Cerebrum

What is Cerebrum?

Cerebrum is the largest part in any mammal’s brain. It consists of

1. The Cerebral cortex, which plays a key role in many important aspects of life, such as memory, attention, perception, cognition, awareness, thought, language, and consciousness
2. Hippocampus, part of the brain used for consolidation of information in short-term and long-term memory, as well as spatial memory, so the way we perceive 3D objects and navigate in space
3. Basal ganglia – a group of subcortical ganglia, connected with our motoric skills, procedural learning, emotion and some more primal habits (which are almost reflex-like, for example teeth grinding or mouth twitching)
4. Olfactory bulb, a part of the brain that is connected with the sense of smell

and some other, less important parts of the brain.

What is Cerebellum?

The name stems from Latin, meaning “little brain”, although it’s really the second largest part of the brain, the first being cerebrum. It’s connected primarily with movement, as well as language and attention and some more primal feelings, such as pleasure and fear. Our coordination, accuracy and precision are guided by this part of the brain, and it’s the part that’s mostly used when, for example, learning how to ride a bike.

What are the Similarities between Cerebellum and Cerebrum?

Since the size and usage of these parts of the brain vary with different species among mammals and vertebrates, I will consider humans in this text and focus on similarities and differences in the particular case of the human brain.

• The cerebellum and cerebrum are fairly dissimilar, so the only similarities that could be listed here are pretty vague, and it comes down to these:
• They both participate in the regulation of movement and motor functions, as well as learning
• They both communicate with the thalamus and the colliculi
• They are both divided in two hemispheres (the cerebral and cerebellar hemispheres), although with a different structure (see Differences)
• They both have grey matter on the outside and white matter on the inside, although the way they innervate into each other is different (see Differences)

Apart from that, finding any more similarities would be a far stretch of the truth.

Difference Between Cerebellum and Cerebrum 

1. Size 

Cerebrum is the largest component in the brain, while cerebellum is the second largest.

2. Mass

While the cerebrum takes up 83% of the total brain mass, the cerebellum forms around 11%.

3. Location

Cerebrum is located in the forebrain while cerebellum is located in the hindbrain.

4. Hemisphere separation

Although both cerebrum and cerebellum are separated into two hemispheres, cerebrum is separated with a structure called the median longitudinal cerebral fissure, which is different from the median vermis that separates the cerebellum into his hemispheres.

5. Arbor vitae formation

Arbor vitae is a structure that forms when there is a neural structure with white matter on the inside and grey matter on the outside, and the white matter innervates out into the grey matter. Cerebrum forms arbor vitae, since the white matter innervates out in that case. Cerebellum also has white matter on the inside and grey matter on the outside, but in this case grey matter innervates inwards into the white matter, not forming arbor vitae.

6. Activity control

Cerebrum is responsible for voluntary actions, motoric functions, cognition, awareness, and consciousness, while cerebellum has an important role in movement control, languages and some emotions.

7. Cortical layers

In a human brain, cerebrum will have 6 cortical layers, while cerebellum will have 3.

8. Lobes

While cerebrum consists of four distinctive lobes: frontal, temporal, parietal and occipital; cerebellum doesn’t form any lobes.

9. Number of neurons

Cerebellum alone consists of more than 50% of the total number of neurons in the human brain, which means that it has more neurons than cerebrum.

10. Evolutionary progression

The cerebellum has evolved first over the years, and it has been assumed that’s why it’s located in the hindbrain, why it’s smaller than the cerebrum and why it controls more basic and primal actions, feelings and instincts.

11. Senses and equilibrium

While the cerebrum is responsible for our senses, the cerebellum takes care of our inner equilibrium (by secreting hormones)

Cerebrum vs. cerebellum in a tabular form

Summary

• Cerebrum and cerebellum are both parts of the human brain playing an integral role in our everyday life.
• Cerebrum is responsible for our voluntary actions, motoric functions, cognition, awareness, and consciousness. It forms 83% of the brain’s total mass and is the largest component of the human brain. It is divided into two cerebral hemispheres and four lobes: frontal, temporal, parietal and occipital.
• Cerebellum is responsible for movement control, languages and some emotions. It forms 11% of the brain’s total mass and is the second largest component of the human brain.
• Perhaps counterintuitively, cerebellum is formed with more neurons than cerebrum, even though cerebrum is larger. Cerebellum consists of more than 50% of the neurons present in the human brain.
• It’s a widely accepted scientific theory that cerebellum was one of the first segments of the brain to form during evolution, while cerebrum was the last.