The mysterious functioning of the Nervous and Endocrine System #1

in #steemstem6 years ago

It is amazing how our nervous system works and that is why I have developed this article. Maybe you find out about things that you did not imagine was happening in your body.

It's Sunday and the clock shows 1:00 a.m. Suddenly you find yourself face to face with a horrible creature. You scream and you wake up from a very deep sleep. Soon you realize that it has only been a nightmare.

annie-spratt-548194-unsplash.jpg
Image edited by the author.Unsplash-Kid/Freepiks-Monster

The creature was a fragment of your imagination. But your reaction was very real. Your heart was beating fast. The rhythm of your breathing accelerated and sweat covered your entire body. Even though it was only a dream, your body seemed ready to run away or face the terrible monster.

The nervous and endocrine systems were working without you noticing. Together, they control the activity of the body. Parts of your nervous system, 'the brain, nerves and sensory organs' get information from the outside world.

They in turn alert the endocrine system to flood the bloodstream with chemicals. It does not matter that the threat is real or imagined, it is likely that one day, when you have to face a real danger, you will thank these two systems for their automatic response.


You look at the clock and you realize that you have been more than half an hour trying to solve the same mathematical problem. "Why is it so hard for me to solve this problem?" you ask yourself. Then you get distracted. You think about summer vacations when you will not have any worries. Suddenly, the solution occurs to you.

This situation, which may be familiar to you, is an example of how the nervous system sometimes works in a mysterious way. The nervous system receives and sends information about activities within the body. It also perceives and responds to changes in the environment.

The incredible amount of information your body receives at any given moment reaches the nervous system in millions of messages. These messages convey information about what happens inside and outside your body, "the itching of your nose, the joke you heard or the smell of a cake." Almost immediately your nervous system tells your body what to do "scratch the nose, laugh at the joke, or eat the cake.

The nervous system keeps your body functioning despite the constant changes in your environment. These changes of the environment are called stimuli.

Imagine this situation. "An insect is directed at one of your eyes and you automatically blink to avoid the damage, in this case the insect is the stimulus and the blinking your response." Some responses to the stimuli are involuntary (they are not under your control) how to blink or sneeze. and many others are voluntary.

From the moment of your birth, the nervous system controls and interprets all the activities of your body. Without this system you could not move, think, laugh, feel pain, or enjoy the taste of a delicious and juicy taco.


At all times the nervous system is very busy. It receives and sends a constant flow of information from one part of the body to another. Every second, hundreds of these messages travel through the body. They are transmitted through ducts formed by special cells called neurons.


Pixabay

Neurons, unlike other cells, can never be replaced. But this is no reason to worry. The large number of neurons with which we are born lasts a lifetime.

Around the cell body are the thin structures called dendrites that carry messages to the cell body. An elongated fiber called axon emits messages from the cell body.

But how does a message actually travel through a neuron?

When a nerve impulse is transmitted through one neuron or from one neuron to another, it does so in the form of electrical or chemical signals. An electrical signal that in simple terms is the change of position of positive and negative charges, moves a nervous impulse through a neuron. A nerve impulse can travel through a neuron at a speed of 120 meters per second.


Giphy-Harvard University

The way in which a nerve impulse travels from one neuron to another is a little more complex. The reason is that the neurons do not touch each other. There is a small space between two neurons called synapses. Somehow the nerve impulse must "jump" the gap.

But how? Think of the synapse as a river that divides a road. When a car reaches the river, it crosses it on a ferry. Then, return to the road to continue your trip.

  • Similarly, a nerve impulse is "ferried" across the synapse by a chemical signal. The terminals of the axon emit these chemical signals when the nervous impulse approaches the synapse. The electrical signal that drove the nerve impulse to this point stops, and the chemical signal carries the nerve impulse through the synapse to the next neuron. Then the chemical signal again originates an electrical signal, and the process is repeated until the nervous impulse reaches its destination. *

Then a 3D Animation so they can understand more the functioning of the nervous system.


We know that the neuron is the basic unit of the structure and functioning of the nervous system. However, they do not act alone, they are part of a complicated communications network that forms the human nervous system. The nervous system is divided into two parts: the central nervous system and the peripheral nervous system.

Central Nervous System

If you were asked to write the names of ten of your favorite music stars, and at the same time to list out loud the fifty states of the country, it is likely that you would say that it is impossible. And you would be right.

It is obvious that the nervous system can not control certain functions when it is occupied with others. What is not clear is how many functions you can control at the same time.

Even the simple action of sitting in the cinema watching a movie requires several mental operations. Many different impulses travel between your nervous system and other parts of the body while watching a movie. Some impulses control your vision and the amount of light you perceive. Others control your interpretation of what you see and hear, and there are others that regulate your breathing and blood circulation.

All these impulses can be related to each other. For example, if the movie is horror, it is likely to increase the rate of your breathing and your heartbeat. If, on the other hand, it is very boring, they will decrease and you can even fall asleep!

The activities that occur in the central nervous system are very complex. The two parties that are in charge of interpreting the information that arrives from all parts of the body and sending them the appropriate answers are: the brain and the spinal cord.

The encephalon is the main control center of the central nervous system. It transmits and receives messages through the spinal cord. The spinal cord is the connection between the brain and the rest of the body.

Despite the presence of billions of neurons, the mass of the brain is only 1.4 kilograms. As befits such an important body, it is very well protected.

A bone protection called the skull covers it. It is also covered by three layers of connective tissue, which nourish and protect it. The inner layer adheres to the surface of the brain and conforms to its numerous folds.

Between the inner layer and the middle layer there is a watery liquid. This liquid bathes the brain and protects it from sudden impact, like when your head collides with someone else's during a football game or you fall. The outer layer that is in contact with the inside of the skull, is thicker and more resistant than the other two.

This article has been a small part of the mysterious and perfect functioning of the nervous system. We could appreciate that the nervous system works efficiently in complex processes, if we consider that it takes only a few milliseconds to react.

Do not miss the next post. Thanks for reading.


Sources:
[1. Prentice Hall Science - Human Biology] - 2. Encephalon - Wikipedia - 3. Nervous system - Wikipedia

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