Let us learn about the most complex and important organ in the body, Human Brain. Brain controls all the functions in our body. Brain processes and interprets the information. Brain receives all the information through our 5 senses namely, touch, taste, hearing, sight and smell. 

Your thoughts, vision, emotions, skills, movements, speech, memories, dreams, imagination, creativity, function of various organs is controlled by the brain. The central nervous system is composed of Spinal Cord and the brain.

The brain is the broadest and uppermost part of the central nervous system. It is the highest coordinating center of the body. The brain is a soft, whitish organ that weighs 1.2-1.4 kg and forms about 98% of the weight of the whole central nervous system. It has about 100 billion neurons. The brain is situated in the cranial cavity of the skull present in the head region of the body. The bones of the cranium or the brain box protect this delicate organ from mechanical injury. The brain is surrounded by three membranes called meninges which provide protection to it. The space between these three meninges is filled with cerebrospinal fluid which protects the brain from mechanical shocks.

 

Human Brain

 

Main Parts of the Human Brain: The Brain has different parts that work together to perform various tasks. Let us learn about different parts of the brain.

The brain is divided into three main regions:

• Forebrain
• Midbrain
• Hindbrain

1. Forebrain

The largest region of the Brain. Forebrain processes information related to Complex cognitive activities, sensory and associative functions. The thinking function of the brain is done by the forebrain. It forms the greatest part of the brain and is the main thinking part. It has regions that receive sensory impulses from various receptors. It further consists of three regions:-

1. The first region is the olfactory lobes- These are the parts of the forebrain that are involved with the perception of a smell.

2. The second region is the cerebral hemisphere or cerebrum- Made up of the cerebral cortex and other subcortical structures, the cerebrum is the largest part of the brain.

Each cerebrum is divided into 4 lobes:

• Frontal lobe- the region for speech, facial muscular activities as well as higher mental activities. �It plays a major role in memory, attention, motivation, problem solving,�
• Temporal lobe- the region for auditory reception (hearing).�It is associated with the formation of memories and processing hearing information.�
• Occipital lobe -the region for visual reception (sight)
• Parietal lobe- the region for touch, taste, smell, temperature, and conscious association. It controls sensation and processes information about temperature, taste, touch, and movement.

Each lobe has some areas called association areas which store information and experiences and control thinking, memory, learning, and emotions

3. The third part of the forebrain is the diencephalons- It is the posterior part of the forebrain that connects the midbrain with the cerebral hemispheres and contains the thalamus and the hypothalamus. It is also called between the brain or interbrain.

Diencephalons control and maintains: Hunger, thrust, fatigue, sleep, body temperature, sweating, emotions, etc. It also secretes neurohormones that regulate the secretions of the pituitary gland.

Hypothalamus plays a major role in controlling bodily functions also it controls the release of hormones from the pituitary gland. The location of hypothalamus is below thalamus. Hypothalamus is associated with regulation of body temperature, controlling of emotions and mood, blood pressure, heart rate, sense of taste and smell.

• Thalamus: It is associated with memory retention. Thalamus is present above the brainstem. It conveys sensory information from the various sense organs. 

2. Mid Brain: The second part of the brain is the midbrain. It is a significantly small region and controls the reflex movement of the head, the neck, and the trunk in response to visual and auditory stimuli and also controls the eye muscles, changes in pupil size as well as shape of the eye lens.

Mid brain connects the forebrain to the hindbrain. Movements, vision, hearing, temperature regulations, and spontaneousness are all functions of the midbrain.

It is made up of:

• Tectum: The tectum is the back part of the midbrain. The reflex movement of the eye, head, and neck muscles is controlled by the tectum. The tectum is responsible for visual and auditory reflexes.
• Tegmentum: It is a motor center that relays inhibitory signals to the thalamus and basal nuclei which prevents unwanted body movements.

3. Hind Brain: The third part of the brain is hind brain. Heart rate, breathing, Salivation, Vomiting, blood pressure, sleeping and waking up functions are managed and induced by hindbrain. 12 cranial nerves are located in hindbrain. 

The hindbrain consists of 3 parts-

• Cerebellum
• Pons
• Medulla oblongata

The cerebellum: Located in the posterior area of pons and medulla. It is the second-largest part of the brain. It maintains posture, equilibrium, and muscle tone

Pons controls some aspects of respiration.  Located underneath the hindbrain, pons serves as a coordination center for signals and communications that flow between the two brain hemispheres and the spinal cord.

Medulla oblongata: It is the lower part of the brainstem measuring only about 3 cm long. Medulla is responsible for controlling autonomous functions of the brain such as respiration, heartbeat, breathing and other involuntary reflexes. Medulla also connects the spinal cord and the cerebral cortex. 

It controls:

• rate of heartbeat
• breathing movements
• expansion and contraction of blood vessels to regulate blood pressure
• swallowing, coughing, sneezing, and vomiting

So we see the human brain is a very important part of our central nervous system (CNS) and allow us to think and take actions based on thinking.

Human Brain Facts

1. The human brain weighs around 1.5 Kg
2. 2% of our body's weight is contained by Brain
3. Busting a very popular myth which is that you use only 10% of your brain's capacity. This belief is false, we use 100% of our brain!
4. Our brain itself can't feel pain.
5. 20% of the oxygen and blood in your body is consumed by the Brain. 
6. The brain is made up of approximately 100 Billion neuron cells, 
7. Compared to daytime, your brain is more active during the night.