Neurons. The key component to how we think, feel, and act. If it weren’t for neurons, we would live a senseless and boring life. Luckily, we have no shortage of neurons in our world. With billions of people, and even more animals covering the earth, neurons are everywhere, allowing us to experience the world in all its glory. Now that we know how important they are, let’s talk more about how they do all these amazing things.
The neuron was first recognized as the primary unit of the nervous system in the late nineteenth century. They were discovered through the work of Santiago Ramon y Cajal. He used a process known as the silver staining process to make the structure of individual neurons visible. To do this, he used a technique called “double impregnation,” which is still used today. In 1888, Ramon wrote and published a paper about the bird cerebellum, including an in-depth look at many different aspects of how it works. In his paper, he discovered a principle which proved to be true amongst all neurons. This principle became known as the Neuron Doctrine. Three years later, in 1891, a German scientist by the name of Heinrich Wilhelm Waldeyer wrote an in-depth review of the Neuron Doctrine which first introduced the term “neuron” as we know it today.
Neurons, as stated earlier, are the primary functional unit of the nervous system. As such, there are many different types of specialized neurons meant for different purposes. These include sensory neurons, in charge of receiving signals from all your sensory organs, motor neurons, in charge of controlling everything from muscle contraction to glandular output, and interneurons, in charge of connecting neurons to other neurons of the same type. These many different types of neurons all come together to make up the majority of our brain, spinal cord, and peripheral nervous system.
A typical neuron is made up of the main cell body, dendrites, and the axon. The cell body is fairly simple, containing a nucleus, several mitochondrion, and a Golgi apparatus. The cell body is the “brain” of the neuron, in charge of interpreting received information. The cell body is covered in many thin, hair-like structures called dendrites. These dendrites branch off in many different directions and cans extend several hundred micrometers from the cell body. The dendrites are in charge of receiving information from other cells. Axons are what we call a special cellular extension. They extend off of the main body at a point called the axon hillock, and travels for as far as one meter in humans, and even more in some other species. Axons are in charge of sending received information to other neurons. This information that is sent between neurons can either be an electrical or a chemical signal. This is possible due to the fact that neurons are electrically-excitable, meaning that electricity is received and sent with ease within the cell.
Neurons are such an important structure in all living things. They are responsible for making us do what we do, and helping us understand how we do it. Through the constant sending and receiving of information all throughout our bodies, they keep us functioning and help us grow. It is amazing how such a small, simple thing can change our lives, for better or for worse.
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