Function of the brain parts: cerebrum, cerebellum & brainstem

Overview

Yes, you read it right. Today, I am going to explain the various parts and function of the brain.

Have you ever seen a picture of the animal's brain?

You must have found the smooth surface of the brain because it has significantly less folding (no gyri, sulci, and fissure). Generally, an animal's brain is not much complex as the human brain. They are known as?the?Lissencephalic brain.

In contrast to the human brain, it is not the simplest organ. It is so much complex due to its many infoldings (irregular) like outer surfaces in the form of multiple gyri (ridges), sulci (minor groove), and fissure (large groove). So, they are known as?the?Gyrencephalic brain.

?Due to its complex structure, the human brain is the most intelligent species on the earth.?

Friends! Whatever you do in your daily life is controlled by your brain, such as thinking, learning, feeling, dancing, even breathing, and your heart rate.?

Your brain is like a boss as it controls everything.?

The human brain is the largest organ that helps to control your body's voluntary and involuntary activities.

So, it is important to know about the function of the brain.?Let's start this topic with basic information –

Structure of brain

The brain is an essential part of your nervous system.

Your body is connected with the nervous system. The nervous system is divided into?CNS (central nervous system)?and?PNS (peripheral nervous system).?

CNS consists of the brain and spinal cord.?

The brain looks like a?walnut?shape because they have many folds.

?Your brain is protected with skull bones. Then your brain adheres or covers with a membranous layer is called?meninges.?

Meninges has three layers -?dura mater?(outer),?arachnoid mater?(middle), and?pia mater?(inner). These meninges provide further protection of the brain and spinal cord.

The space between the dura mater and arachnoid mater is called?sub-dual space.?

The space between the arachnoid mater and pia mater is called?subarachnoid space. It contains?cerebrospinal fluid?(CSF).?

CSF also circulates in the brain's ventricles. It helps to provide nourishment, waste removal, and protecting the brain.

CSF acts as a shock absorber by preventing sudden temperature and pressure changes.

Basic function of the brain

The primary function of the brain?is to collect information from the environment or the sensory organ of your body by the peripheral nervous system. In return, the brain produces a motor response.?

For example, if you see delicious food and the smell of food. This information goes to your brain. Then in response, motor output releases saliva, gastric juice, etc.?depend upon your activity.

So, your brain gets the information by following steps –?

• receive information
• integrate the information
• process the information
• coordinate the information with the sensory organ
• make the decision and send the motor output

?The motor output may be movement of muscle, secretion by the gland, gastric motility changes, etc.?

If the action is automatic and rapid is called?reflex action. For example - coughing, sneezing, sudden jerky withdrawal of hand or leg when you touch a hot object, etc.?

They all are interconnected with neurons which help in communicating with each other.?

Parts of brain with functions

Our brain is divided into main three parts –?

• Cerebrum?
• Cerebellum
• Brain stem

Every part of your brain controls different functions. So, let’s start with the most prominent part of the brain, called?the?cerebrum.

1. Cerebrum?

The cerebrum is generally divided into two halves which are called the?cerebral hemisphere.?

A longitudinal fissure (deep grove) from the center divides these two hemispheres (left and right), which is connected by a bundle of nerve fibers called?corpus callosum?(white matter).?

This corpus callosum allows communication between the two hemispheres.?

Your cerebrum is?contralaterally?organized. It means the right side of the cerebrum controls the left side of your body, and the left side of the cerebrum controls the right side of your body.

The cerebrum has three layers – outer (grey matter), center (white matter), and inner (grey matter-like basal nuclei).?

The superficial (outer) part of your cerebral hemisphere is called the?cerebral cortex. It is made up of grey matter, and the rest of the portion is white matter except the brain nucleus.?

Here, I want to clear the difference between grey matter and white matter.?

Grey matter?is basically that portion where a lot of neuronal cell bodies are collected together. Whereas a tail portion of nerve cells (axon and nerve fibers) is called?white matter.

Some pieces of grey matter embedded within the white matter of the brain are called?nuclei.?

The outer (surface) cerebral cortex is infolded in the form of gyri, sulci, and fissure.?

The ridges and wrinkles of your brain surface are called gyri (single–gyrus). The small groves are called?sulci?(single – sulcus), and the large groove is known as a?fissure.

The gyri, sulci, and fissure determine intelligence. The increased number of wrinkles in your brain reflects more intelligence. It shows more number of neurons.?

Fissure?

The fissure is anatomically boundaries that divide the lobes. The main cerebral fissures are –?

a. A lateral fissure or Sylvian fissure (occurs between frontal and temporal lobe)

b. Central fissure or fissure of Rolando (occurs between frontal and parietal lobe)

c. Parieto-occipital fissure (between parietal and occipital lobe)

d. Transverse fissure (separate cerebrum from cerebellum)

e. Longitudinal fissure (divides the cerebrum into two hemispheres)

Lobes?

The cerebral cortex comprises four parts or lobes – frontal, parietal, temporal, and occipital lobe. Let us know each lobe and?function of the brain cerebrum?–?

a. Frontal lobe

It is the anterior (front) part of each cerebrum. It is present in front of the parietal lobe, which is separated by a central fissure.

The frontal lobe includes four main areas –?

Primary motor area (Brodmann area 4) -?It is a thin strip located at the dorsal (back) portion of the frontal lobe. The primary function of this area is to control the voluntary skeletal movement of your specific body parts.?

You can move your limbs and fingers as per your will with the help of this area.?

Premotor area (Brodmann area 6) –?It is located immediately anterior (front) to the primary motor area.?It has a diverse function and is not fully understood. But it is more concerning that a learned pattern of movement can be repeated.?

Motor speech area (Broca's area) –?This area is located just above the lateral fissure.?The primary function of this area is linked to speech production. It controls the muscle movement needed for speech.?

Prefrontal area –?It covers the remaining portion of the frontal lobe. It is the largest area of the frontal lobe. It performs intellectual functions such as problem-solving, thinking, planning, organizing, emotions, behavior control, decision-making, and personality.

b. Parietal lobe?

The parietal lobe is the largest lobe of your brain. It is located just above the temporal lobe and behind the frontal lobe.?

It includes two main areas –?

Somatosensory area –?It is located immediately posterior (behind) the central fissure. This area receives sensation from the entire body. It perceives the sense, including pain, temperature, pressure, touch, awareness of muscular movement, and position of joints.?

Taste area (gustatory cortex) –?It lies just above the lateral fissure. This area is responsible for a taste sensation.?

c. Temporal lobe

It is located below the lateral fissure on both sides of the cerebrum. It has 3 main areas –

Sensory speech area (Wernicke's area) –?It lies adjacent to the temporo-parieto-occipital region of the brain. The primary function of this area is comprehension (ability to understand) of spoken language.?

While Broca's area (motor speech area) is involved in the production of speech.?

Due to this area, you can understand the meaning of spoken words.?

Auditory area (hearing area) –?It is located immediately below the lateral fissure within the temporal lobe. It is connected with the 8th cranial nerve (vestibulocochlear nerve).?

It has a major role to perceives hearing information.?

Olfactory area –?It is located deep in the temporal lobe and connected with the 1st cranial nerve (olfactory nerve). It helps to perceive a sense of smell.

d. Occipital lobe?

It is located at the very back of the brain and lies behind the?parieto-occipital fissure. It is connected with the 2nd cranial nerve (optic nerve). The primary function of this lobe is to perceive visual information.?

Other areas of the cerebrum?

The deep brain (inner part) contains sub-cortical structures - thalamus, hypothalamus, and basal nuclei. They are made up of grey matter. They all are present in the diencephalon division.?

Basal nuclei?– It is strongly interconnected with the cerebrum, thalamus, brain stem, and other areas of the brain. It is responsible for controlling body movement and coordination. This component of your brain helps in eye movement, behavior, decision making, motivation, and working memory.?

The dysfunction in basal ganglia causes hyperkinetic neurological disorders like Parkinson's disease, Tourette syndrome, Tardive dyskinesia, obsessive-compulsive disorder, stuttering, ADHD (attention deficit hyperactivity disorder), cerebral palsy, and other diseases.?

Thalamus – It is a mass of grey matter located at the core of the diencephalon. The primary function of the brain thalamus is to pass motor (CNS to periphery), and sensory (periphery to CNS) signals to the cortex.

Hypothalamus?is an almond shape located below the thalamus near the pituitary gland and a part of the limbic system. It plays a crucial role in hormone-releasing, temperature regulation, circadian rhythm (biological clock), and hunger.

The limbic system is more concerned with learning, emotion, motivation, and memory.?

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2. Cerebellum

Next comes a relatively small portion but an essential part of your brain called the cerebellum. It is also known as "Little brain."

It comes under the hindbrain (metencephalon). It is a separate structure attached to the bottom of the brain behind the pons and fourth ventricles.

Like the cerebrum, it also consists of two hemispheres separated by a narrow midline called?Vermis.?

The outer cortex of the cerebellum is made up of grey matter, and its surface is tightly folded in gyrus and ridges called?folia.?

Inside, there are some masses of grey matter (nuclei) scattered within the white matter of the cerebellum.?

Some nerve fibers of the cerebellum are connected to various parts of the brain stem. They are arranged in 3 bundles –

a. Superior cerebellar peduncle (connect the cerebellum to midbrain)

b. Middle cerebellar peduncle (connect the cerebellum to pons)

c. Inferior cerebellar peduncle (connect the cerebellum to medulla oblongata)

Your cerebellum controls the motor system?ipsilaterally.?It means the right side of the cerebellum controls the right side of your body, and the left side of the cerebellum controls the left side of your body.?

It receives the information from other parts (like the brain stem and cerebrum) of your brain. Then it uses the incoming information to coordinate and control voluntary movement.

Cerebellum has three main functions –?

• Maintain the?tone of muscle?
• Maintain?posture and balance?while walking, running, jumping, and dancing
• Coordination of movement?

Without the cerebellum, you cannot control balance. You may face difficulty in balance. Suppose there is a problem with your?cerebellum function. In that case, it may cause ataxia, cognitive impairment, dystonia, unsteady gait, tremors, and vertigo.

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3. Brain stem

The brain stem is the posterior (back) part of your brain that is connected to the spinal cord.?

It controls those areas of your body that you don't need to work like breathing, digestion, maintaining heart rate, etc.?

It involves the autonomic nervous system or autonomic nervous pathway. The brain stem has three main parts –?Midbrain?(superior segment),?Pons?(middle piece), and?Medulla Oblongata?(inferior element).?

The?function of the brain?stem is to control other organ's activities with the help of critical cranial nerves which emerge from the brain stem.?

Takeaway

In the above, we have seen various?parts and function of the brain.

The brain is such a vital organ of your body. Your brain has many complicated parts, and each part of the brain has a different function.?

So, you must care of your brain. You should always –?

• Wear a helmet while riding
• Do brainstorming exercises, meditation, yoga, and cardio exercise regularly to increase intelligence power, memory, and learning.?

I hope you like this post–function?of the brain. If you found this post helpful, please don't forget to share it on social media.?