What is the Nervous System? | Types, Definition, Structure, Function & Facts

What is the Nervous System?

The nervous system is made up of the brain, spinal cord, and an extensive network of nerves that cover all parts of the body. Together, the nervous system helps different parts of our body communicate and allows our brains to control what’s going on. Without a nervous system, our brains would be chaotic. He will be oblivious to what is happening in the outside world and will not be able to control our bodies.

The brain and spinal cord make up what is known as the central nervous system. The rest of the nerves together are called the peripheral nervous system.

Nerves – Peripheral Nervous System

Nerves are like wires that carry signals to communicate with or around the body. Inside each nerve is a bundle of nerve fibers. Some nerves are very long, such as the one that runs from the legs to the spinal cord. Nerve cells are called neurons.

There are two main types of nerves: motor nerves and sensory nerves.

Motor Nerves – Motor nerves allow the brain to control our muscles. The brain sends signals to the motor nerves to tell our muscles to relax or contract so we can move.

Sensory Nerves – The second type of nerves is called sensory nerves. These nerves transmit signals to the brain to tell it what is happening in the outside world. They come from the skin (touch), eyes (sight), tongue (taste), nose (smell), and ears (hearing).

In each case, the signals only go in one direction: motor signals travel from the brain to the muscles, and sensory nerve signals travel from the senses to the brain.

In each case, the signals only go in one direction: motor signals travel from the brain to the muscles, and sensory nerve signals travel from the senses to the brain.

In the peripheral nervous system, there are also two main sets of nerves: the autonomic nervous system and the somatic nervous system.

Autonomic nervous system – This set of nerves works automatically. We don’t have to think about it, the brain does everything for us. It takes a lot of concentration if we have to constantly command the heart to beat or the digestive system to secrete certain enzymes. I’m sure I’ll forget and die instantly! Fortunately, the autonomic nervous system takes care of that for us.

Somatic nervous system – These are the nerves that we actively control, such as jumping with our feet or moving our arms.

The Neuron

Each nerve is made up of several cells called neurons. To know more about neurons, let us take the example of motor neurons. Each motor neuron has three important parts: the cell body, dendrites, and axon. Dendrites are branches of the main cell body. They talk to the dendrites of the cell next to them through what is called a synapse. Axons connect to muscles and tell them what to do.

Reflex

Our bodies are super smart. Sometimes we have to go so fast that our brains don’t have time to think. Therefore, our body simply ignores the brain. It happens when we touch something hot. Our hands actually move before the brain commands. The brain eventually figured out what was going on, but our bodies made the right choice and acted first. Your doctor will test your reflexes by tapping your knee in a certain position to see if your leg moves without you thinking.