Skip to main content

Nervous System And Human Brain

Nervous System and Human Brain




Our nervous system allows us to think, feel pain, heat, cold etc. and to have a reflex action to certain stimulus. Without our nervous system, we could not survive. It is one of the fundamental life processes. Largely, organisms can be divided into those which have vertebrae, and those which don’t. We will be talking about those which have vertebrae in this article. The organisms included in this group are of the Phylum Chordata, such as humans, cats, dogs etc.

The cells associated with this fundamental process are neurons or nerve cells. These are long cells which transmit nerve signals. These are also the longest cells in the body. The signals are sent rapidly through the thin axons in the form of electrochemical waves. This leads to the release of neurotransmitters at the junctions of nerve cells, known as synapses. This leads to the formation of a neural network, which helps us utilize the nervous system. Nerve cells can reach every cell in the body and receive a reply. This is a very quick process.




The nerve cells consist of a long thin fiber known as axon, which is wrapped by myelin sheaths. This not only speeds up the nervous system but also acts as an electrical insulator. These sheaths have gaps, and two sheaths are connected by the nodes of Ranvier. These nodes help in flow of ions, which in turn speeds up the process. At one end of the neuron, are the axon terminals, which receive the signal to be transmitted. At the other end is the cell body. The nucleus is also there, including dendrites which actually help in giving out the signal, so it can be transmitted further.

Another type of cell associated with the nervous system is the lesser known glial cells. Glial cells do not transmit signal, but are there for the support of the neurons. They also provide nutrients to the nerve cells, act as electrical insulators, remove any pathogens and dispose of dead neurons. A very unique glial cell, oligodendrocytes (CNS) and Schwann cells (PNS) create myelin that covers the axon of the neurons in sheaths. There are about as many glial cells as there are neurons in the brain, but their concentration in various areas in different.

The main two parts of the nervous system are the CNS and PNS. The CNS (Central Nervous System) consists of the brain and the spinal cord. The PNS (Peripheral Nervous System) consists of a bundle of neurons that connect to every part of the body. Therefore a message sent by CNS can arrive at any place in the body through PNS.

Let us take an example. If we want to lift our finger, the CNS gives an order to lift the finger. The order is transmitted through the spinal cord and further through the PNS. The order transmits from dendrite to axon, and finally reaches the finger. There, it gives an order to finger muscles to contract or relax. This may seem like a complicated process, but it is all done in an instant.

Let us discuss about the human brain as a final topic now. The brain gives us the ability to think, and interprets signals from various parts of our body to give us the abilities to see, touch, hear, smell and taste. It also moulds our personality and decides how we react to physical and emotional stimulus. It size is just 1260 cm3 for men and 1130 cm3 for women, and it weighs around 1.2 – 1.4 kg. It accounts for 2% of our body weight.



The human brain is protected by the skull, and is one of the essential organs in the human body. The brain has two hemispheres: Right and Left. It also consists of three parts: the cerebrum, cerebellum and brainstem.

The cerebrum is the part of the brain which is the interpreter of touch, vision, hearing and emotions, and controls fine control over movement. The cerebrum composes of the right and left hemisphere of the brain. It is the biggest part of the brain and has four lobes:
1.     Frontal lobe – It controls personality, emotions, behavior, body movement, judgment, speech, intelligence, concentration and self-awareness.
2.     Parietal Lobe – It controls vision, language and words, touch, pain, temperature, hearing, motor, sensory, memory and spatial and visual perception.
3.     Occipital lobe – It controls vision, it interprets the colors, light and movement.
4.     Temporal Lobe – It controls language, memory, hearing, sequencing and organization.






The cerebellum is the part of the brain which controls muscle movement, maintains posture and balance. This may seem like less work but if you think about it, these are extremely important functions.

The brainstem connects the rest of the brain to the spinal cord. It controls our basic functions such as breathing, heart rate, sneezing, vomiting, swallowing, body temperature, wake and sleep cycles etc.


The Right and Left Hemispheres perform almost the same functions, but have some independent functions of their own. The Left Hemisphere controls the right side of the body and the Right Hemisphere controls the left side of the body. The Left Hemisphere also controls hand use and language in about 92% of people. The Right Hemisphere controls creativity, artistic skills and musical skills.


Enjoy your high school with - High School Pedia : www.highschoolpedia.com

Labels:

Comments

Post a Comment

Popular Posts

Piezoelectric Crystal

Piezoelectric Crystal {literally_pressing electricity} Ever wondered what it might be like to live in dark or sleep in a hot summer day without an AC ? Absurd, isn't it ? But with the rate at which we are using our resources, it may not be long before it actually happens. Scientist across the globe are searching for new resources, stocks and technology to prevent the near, unpleasant future of current and the next gen. One of these, an unexploited tech is that of Piezoelectricity. Piezoelectricity is an ability of some special materials (like crystals of quartz, ceramics of lithium niobite, gallium arsenide, zinc oxide) to trigger an electric charge when supposed to mechanical stress. These materials are available in basic instruments that we use in our daily life like microphones, quartz watch, gramophones. All these materials are run by the piezoelectric current. But how does it work? When you apply force (mechanical force) on it, an electric potential, on eit
1 comment
Read more

The Inverse & Reciprocal TRIGONOMETRIC Functions

So, this is my second post on trigonometry. In this post we're gonna cover the reciprocal and the inverse Trigonometric functions. If you haven't seen my first post you should definitely view it as it covers the basics of Trigonometry The Reciprocal Trigonometric Functions The reciprocal Trigonometric function of Sine is Cosecant, of Cosine is Secant & for Tangent it is Cotangent. Cosecant (Csc θ = 1/Sin θ) or (Hypotenuse/Opposite) Secant (Sec θ = 1/Cos θ) or (Hypotenuse/Adjacent) Cotangent (Cot θ = 1/Tan θ) or (Adjacent/Opposite) We can also represent Tan θ in another way. As Tan θ = opposite/adjacent  & Sin θ = opposite/hypotenuse  & Cos θ = adjacent/hypotenuse ∴ Tan θ = Sin θ/Cos θ (The hypotenuses cancel out) As Cot θ = 1/Tan θ  So, we can also represent Cot θ as Cos θ/Sin θ.
2 comments
Read more

High School Pedia

It is an initiative by some students to spread the light of knowledge to everyone and everywhere. It was started in the year 2015 and has grown rapidly in the past few months. By the means of this website, we try to provide information on every topic that we can reach up to. You can find different articles on this website. All these articles are written in simple language so that everyone can understand it and learn from it. We at High School Pedia believe in creative learning and this is the reason why we add our own edited graphical representations in every article. Once a very learned man said, “Knowledge increases by not keeping it to yourself but by sharing it with others”. And we follow the same motto “Share to Learn”. The team of High School Pedia tries its best to provide you with the best and original content. Unlike many other websites, High School Pedia is famous for its original and inspiring content.
6 comments
Read more

Anode Ray Experiment

→Anode ray experiment was conducted by E Goldstein. →These rays are also known as canal rays. →This experiment helped in the discovery of the proton. Apparatus Used A discharge tube  was taken in which there were 2 electrodes i.e. Anode(+ve) and the cathode (-ve). The tube was filled with an inert gas. A perforated or porous cathode was used. A layer of zinc sulphide was placed at the back of the cathode. There was a vacuum pump in the tube. High voltage (5000v-10000v) was allowed to flow through the system. It was observed that when the gas was at 1atm(atmospheric pressure ) no change was seen in the tube.  When the   pressure   was decreased inside the tube, a glow could be seen at the back side of the cathode.
3 comments
Read more

Levitation 2

LEVITATION II To be completely honest I was going to start this with a pun. I did think of one but it doesn’t float… I am sorry I just had to. Anyway, this is the second part to the article on super cool ways of making things levitate. Go check the first part out if you haven’t already. Actually, the first part may have become repulsive with all the magnets and stuff, but I promise this will be more attractive. Get it? No? I’ll stop now. I am just going to jump straight into it. 1.    Electrostatic Levitation I know you are probably sick and tired of magnets but they are the best way you know… This method is somewhat similar. You remember that cool science experiment you did with two straws attracting or repulsing each other based on their charge? So basically using the same principle we can make a charged object levitate. But before you try it, let me tell you it won’t be easy. Even impossible according to our Mr. Earnshaw. He even made a law (the law is
10 comments
Read more

Isotopes, Isobars and Isotones

Isotopes These are elements which have the same atomic number but different atomic mass . They have the same atomic number because the number of protons that are inside their nuclei remains the same. But, they have different atomic mass because the number of neutrons that are also inside their nuclei is different. As the number of protons inside nuclei remains same, therefore the overall charge of the elements also remains same as in isotopes: no of protons = no of electrons . Hence, as isotopes overall charge remains neutral, therefore their chemical properties will also remain identical.   Therefore, Isotopes are chemically same but physically different.
3 comments
Read more

Upcoming Marvel Movies

Hey, guys! Today we are going to talk about the 5 most awaited and upcoming marvel movies. Everyone is eagerly waiting right ?!            1) GUARDIANS OF THE GALAXY vol.2 (2017) Last month marvel shared the first teaser of Guardians of the Galaxy vol. 2   describing it as the official sneak-peak. All five main characters- star lord, gamora, rocket, Drax and 'baby' groot . It is set two months after the first movie where the ravagers find out that peter quill double crossed them about the infinity stone (orb). That's all. Everything else is yet to be discovered.                                                                                                                                                                                
Post a Comment
Read more