HUMAN BRAIN

Brain

There are various ways to describe what exactly the brain is. In simple, brain is the creator of central nervous system which controls every part of human body from moving, blinking, walking, talking and many more. The concept of brain is vague. It is always believed that all the activities we perform including hearing, seeing, feeling are the outcomes of brain which is performed via ears, eyes, nose, etc. Only after when brain agrees and gives the instructions to our sense organs to do so.

Brain Structures and their Functions

The nervous system is our body’s decision and communication centre. The central nervous system(CNS) is made of the brain and spinal cord and the peripheral nervous system(PNS) is made of nerves. Together they control every part of our daily life from breathing and blinking to helping you memorize facts for a test.

Nerves reach from the brain to our face, ears, eyes, nose and spinal cord and, from the spinal cord to the rest of our body. Sensory nerves gather information from the environment; send that information to the spinal cord, which then speed the message to the brain. The brain then make sense of that message and fires off a response. Motor neurons deliver the instructions from the brain to the rest of the body. The spinal cord, made of a bundle of nerves running up and down the spine, is similar to a superhighway, speeding messages to and from the brain at every second.

It reacts and response to the stimulus being received from outside environment. Brain issue biological explanation of one giant mass of tissue that contains numerous nervous or nerve cells whose connections with one another determines how to react on what situation.

TYPES OF BRAIN

The brain can be divided into three basic units:

· THE FOREBRAIN

T THE MIDBRAIN

· THE HINDBRAIN

Each of them has its own inevitable importance in determining the role of different part of our body in any given reflexes. More or less the function of these types of brain are highly related to each other:

The forebrain:

It is a larger section of the brain. It is divided into two parts called the lower diencephalon and the upper diencephalon. The lower diencephalon of the brain controls the activities which regulate the body temperature, and sleep states, equilibrium, controlling eye movement, sensing facial movement (salivating, swallowing and chewing food) or sensation and controlling respiration, hearing and speech processing. The upper telencephalon includes the cerebrum, or cerebral cortex. This area of the brain mainly controls personality, memory and cognitive function. It is this part of the brain that affords humans the ability to think abstractly, reason and concentrate. The other functions of forebrain is associative in nature, as the information is received, it connects the new data with previously acquired memories. For example: the smell of garlic reminds you of your mother working in the kitchen. Forebrain being known as emotional brain might lead to depression if deficiency occurs in it.

The Midbrain:

A short stem which serves the function of being a path between the forebrain and the hindbrain is known as midbrain. Midbrain controls the auditory, eye movement, vision and body movement. The various functions which involve are controlling the respiratory muscles, controlling the vocal cords, enabling a person to phonate, oral as well as nasal passages that are known to cause resonance effect are controlled by midbrain. The midbrain also controls the plate, tongue, lips and mandible (lower jaw bone) which are involved in articulation control (control of speech, sound). The coordinated activities of oral facial tissues are controlled by the midbrain due to which it has control over the way we laugh and cry. That is the reason why even if the remaining brain is dead, a person can still laugh and cry. Dopamine is manufactured by midbrain’s nuclei and neurons. This dopamine plays an important role in motor and cognition functioning and the deficiency in this neurochemical may lead to paralysis, development of Parkinson’s disease as well as psychotic abnormalities.

The hindbrain:

The hindbrain helps in developing the connection between spinal cord and brain. It consists of our four main structures which are pons, medulla, reticular formation and cerebellum. Medulla which lies just above the spinal cord helps in controlling breathing, heartbeat rate and blood pressures. On the other hand reticular formation is situated in medulla which controls sleep and attention. Cerebellum which covers 10% of the total brain size handles 50% of the neurons or nerve cells. Cerebellum also known as the “small brain” lies just above pons and next to the ear. The main activity of cerebellum is to maintain the body balance such as postures, movements, eye contact, gestures and so on. The main function of the pons is to connect medulla with cerebellum; when both of them get connected with each other, it could easily maintain the balance between left and right side of the body. Thus, hindbrain functions on the basis of how these structures that come in between the connections of brain and spinal cords performs.

It is very important to understand how the brain works, in how many types they are divided and how each of them performs their task. From the above explanation, it is easily understood though physically under the coverage of layers and layers of skin, one could say that brain is independent but if we just give closer look towards it’s inside working, each of the neurons, tissues, and structures are highly dependent on each another. Thus, before understanding what mind does, it is crucial to know what brain does and its functions.