Every living organism on earth has brain whether it is a bird, reptile, fishes, mammal etc. human brain is different from all the above and controls or instructs all the functions of our body. Like inhaling, exhaling, blood pressure, heart rate, metabolism etc. it collects the information from surrounding environment using five senses in the body and then further interpret it and respond accordingly. Brain is responsible for our dreams, reasoning, emotions, experiences, walk, and talk, to stand, to sit etc. It is of nearly three pounds in weight.
The working of brain is something very complex. It is the millions of small neutrons working with synchronization. Letâ€™s take an example of telephone network all over the world. There are huge numbers of wires and signals each day but the working of single human brain is still more complex. If there is any injury or problem in the brain then it is equal to the problem if all the wires and network is disconnected in a city and that may take a year or more. Our brain contains nearly hundred billion cells that are known as neurons. A neuron is either resting or sending some signals through axon that acts as wire and ends on a small part that gives out chemical. The chemical then moves to the other neurons and conveys the message. Each of the neuron has power to give out chemicals like norepinephrine, dopamine etc and transmit them to other neurons. Its working is same as that of gates and wires in computers. With the help of neurons the signal can be sent to any part of the body. It is made up of three basic parts:-
CELL BODY: – it is the main part that contains everything a cell must have i.e. nucleus, ribosome etc. if this part of cell is damaged then neuron is destroyed.
AXON: – it is a projection that has to take all the signals to the other parts of neuron.
DENDRITES: – these are small projection that connects one cell with the other and helps in the transmission of message.
Neurons are of many types according to its functions: –
SENSORY NEURONS: – these carry the signals from the parts of body to the central nervous system.
MOTOR NEURONS: – carries the messages from central nervous system to the different parts of body.
RECEPTORS: – they take the outside information and change them to electrochemical impulses.
INTER NEURONS: – they join the neurons of spinal cord and brain.
RECEIVING INFORMATION AND TRANSMISSION OF MESSAGES TO THE BODY
Almost all the messages from the body reach the brain through spinal cord which lies on the bottom of brain. If the spinal cord is not there then you will not be able to do any movement of feel any sensation. The information such as vision and hearing go directly to the brain. This is the reason that why during paralyses people canâ€™t move but can se and hear properly.
Messages from the body is received by spinal cord and then go to mid brain from where it spreads to brain surface.
Our brain is divided into two parts i.e. left and right. Right part deals with what eyes see. It recognizes like â€œI know this is a penâ€, â€œnotebookâ€. Etc. So it puts the information together while the left part analyses the information that is in the right and gives it language for e.g.: – right recognizes that this is a pen and left analyses that â€œo yes this is robinâ€™s penâ€.
The part of brain that is responsible for the movement is narrow strip which starts from top of the head to the ear and is known as motor strip. If there is some problem in this part of brain then problems occur in controlling body movements. If this area of left part doesnâ€™t work then right part of brain will not work properly and if there is a stroke on this area on right part then left part doesnâ€™t work properly.
Right handed person has left temporal lobe dominant and vice-versa. Right handed people have the ability in left temporal lobe to understand and express that in words while in left handed it is in right. One part of this lobe recognizes the basic, common sounds while the other deals with complex sounds. For e.g. if we charge a small piece of iron and put it on one part of the temporal lobe then we will only hear a sound or tone. If we put it on complex area then we can recognize a word. If it is on more complex area then we can match the sound with some of the known voices.
Right temporal lobeâ€™s work is to deal with musical sounds and information and recognize noise but it also sometimes works for hearing purposes. If this part gets some problem then we cannot praise any music or sing.
The vision and hearing area of brain have boundaries. Where they meet that is the area that deals with reading. Visual letters are taken in and are converted to sound. Damage to this area can cause dyslexia in which they cannot read properly or cannot recognize the written words.
If we feel some touch or sensation on left hand then the right brain has to deal with it and the information reaches to the area next to that area which has to deal with movement i.e. tactile area. They are located close to each other because sensations and movements are related. Problem in this particular part of brain does not allow the person to feel touch sensations and make movement.
Some parts of brain and their working: –
It has very important functions to play and it lies in the front part. That is why it is called as frontal lobe. One of its functions is planning. Any damage in this part can cause planning problems in the work that has various steps for e.g.: – planning a party, fixing a vehicle etc. other functions of frontal lobe is organization that means we decide which thing has to be done first, second and so on but injury can distract our power of organization.
It controls our emotions deep on the mid brain like aggression, hunger etc. The frontal lobe tells you to grab food when you are hungry. So it deals with these emotions and instructs the body parts accordingly.
Spinal cord provides the path for most of the signals from body to brain and vice versa it is responsible for the reflex actions in our body. In such a situation brain is not involved, spinal cord itself works. It can be taken as different entity, not a part of brain or the downward extension of brain.
It is the largest part of the brain and has deep folds and wrinkles due to which its capacity for processing information is speeded up. It is divided in two parts, the messages from left is sent to right side and from right are sent to left.
It controls over the breathing and blood pressure of body. It also relays signals of body that has come from the five sense organs directly to the brain.
Its work is to connect all the sections of the brain that participates in motor functions, movements of eye and auditory functions.
Its working is to send the outside sensory signals to the appropriate area of cortex. It acts as the gatekeeper for all the messages. It controls temperature of the body, eating, sexual behavior, sleeping.
It is responsible for the secretion of hormones of pituitary gland. It controls reproduction, growth, drinking, eating, and lactation in mothers. Hypothalamus deals with behavioral aspects too like we come to know about the time through daily light and dark circles.
Brain have three layers known as meninges present below the skull. The outer one is known as dura, mid one is arachnoid, inner one is pia. The outer one is tough and protects the brain, the middle one is filled with fluid to provide a cushion for the brain and the inner one is a delicate layer.