Welcome to this lesson on neurons. Today you will be look at a brief introduction into the structure and function of neurons, and the role they play in the nervous system. Specifically, you will learn about:
So the nervous system, first of all, is a body system that collects, interprets, and responds to information about the environment. And neurons are nerve cells. These are the cells that allow the nervous system to collect information, interpret information, and respond to that information or stimuli from the environment.
There are three different types of neurons that play important roles in our nervous system functioning.
A. Sensory Neurons
The purpose of sensory neurons or the function of a sensory neuron is to collect information about stimuli. Any sort of information about the environment around you, they're going to be able to collect that information. Sensory neurons can be found throughout the body and they can sense information like temperature, the chemicals in your extracellular fluid, light, et cetera. You have various different types of sensory neurons that allow us to collect information about different types of stimuli.
Interneurons are neurons found in the central nervous system, which includes the brain and also the spinal cord. They receive information that was collected from sensory neurons and then they process that information.
C. Motor Neurons
Motor neurons are the third type of neuron in the nervous system and their function is to relay information to muscles or glands. Then these muscles and glands are going to carry out some sort of response depending on the information that they receive.
So let's say that you're outside playing catch with a friend and your friend throws the ball to you. Sensory neurons would allow you to be able to collect that information, you would be able to see that the ball is coming towards you.That information would then be sent to interneurons in your central nervous system and your central nervous system would then determine what an appropriate response would be. Let's say that your central nervous system determines that an appropriate response would be to lift your arms up and to catch the ball.That information is then sent to motor neurons, which relay that information to muscles or glands. If the central nervous system decides that you should lift your arms to catch the ball, that information would then be sent to the muscles in your arms. You'd be able to lift your arms up and then catch the ball. That's, briefly, how those three types of neurons work together to collect, interpret, and respond to stimuli.
Take a look at the labeled diagram of a neuron below.
The dendrite is actually and extension of the cell body of the neuron with the nucleus in the middle.
The section as a whole is called the input zone and the input zone is the location where information enters the neuron. So it'll enter through the dendrites and travel in towards the cell body, then you have a little location called the trigger zone. The information will travel towards the trigger zone, and then towards the axon. The long, slender part of the neuron is called the axon.
Information is coming in through the dendrites, through the cell body, down to the trigger zone, and along the axon; you call the next part the conducting zone. Once information gets down to the axon, it travels through the axon endings and then to the output zone.
Now at the end of this output zone you might have another neuron. This neuron has its dendrites, axon, and axon endings. Then the information can then be relayed from the axon endings of this neuron to the dendrites of this neuron. That message will be carried through this neuron to the next neuron, or it could also be passed on to a muscle cell or to a gland cell to relay information as well.
This lesson has been an overview on neurons. Specifically, you got a look at an overview of the nervous system, the various types of neurons and the specific parts of those neurons.
Keep up the learning and have a great day!
Source: THIS WORK IS ADAPTED FROM SOPHIA AUTHOR AMANDA SODERLIND
A body system that collects, interprets and responds to stimuli from the environment.
A nerve cell responsible for relaying information throughout the nervous system.
A type of neuron that collects data about stimuli in the environment and sends the information to the brain.
A type of neuron in the central nervous system that receives incoming sensory information and relays information to motor neurons.
A type of neuron that communicates with gland or muscle cells which then carry out a response as determined by the brain.
A part of a neuron that conducts signals away from the cell body and on to another cell.
A part of a neuron that receives incoming information.