Learn how your peripheral nervous systems keeps the rest of the body in communication with the brain. Consider how two major subsystems help you out with a range of activities, from getting up in the morning to fighting off an attack.
The Body Systems in Action
It’s been a crazy morning for Keith. When he first woke up, he practically jumped out of his skin, heart racing, when he realized he had slept in and was an hour late for school.
Then, as he rushed to make himself some breakfast, he accidentally touched a super hot piece of toast, dropping it and almost burning his hand.He made it to school just five minutes before an important math test was about to begin. For a while, his mind was racing, but soon he was able to focus on his work again and finish the test.This lesson discusses how Keith’s somatic and autonomic nervous system factored into the morning he had and what role they play in a person’s voluntary and involuntary behavior.
Peripheral Nervous System
When learning about psychology and considering the biological side of our behavior, we think a lot about the brain. The brain and spinal cord together make up our central nervous system.
If the central nervous system includes the function of those couple of key areas, you might wonder how a message like ‘get up out of bed’ gets communicated to the rest of the body so that it actually takes that action. This work, and other activities, is up to the peripheral nervous system.The peripheral nervous system is made up of two major parts: the somatic nervous system and the autonomic nervous system.
We’ll start with the somatic nervous system.
Somatic Nervous System
When Keith first woke up, a few things probably happened. He realized he was waking up in bed and perhaps turned his head to check the time and then reacted to the time by jumping out of bed.All of these actions were facilitated by neurons, also known as nerve cells. Some of the neurons were responsible for sending messages to his brain, like when he sees the time using his vision, and that information gets sent to his central nervous system to be processed. Sending information about what he sees is an example of information carried by sensory neurons, the ones that take messages to Keith’s brain about what’s happening in his environment.Other neurons are described as motor neurons because they bring messages from the central nervous system out to the rest of the body, telling his muscles, for instance, to get him up out of bed.
Neurons play a major role in the somatic nervous system, which provides communication between the central nervous system and our organs and muscles. The somatic nervous system mainly deals with voluntary actions, such as moving your body in ways you determine you’d like to move, but it also includes reflexes, like when Keith dropped the toast automatically to avoid burning his hand when it was too blazing hot to hold.
Autonomic Nervous System
Today Keith didn’t just get himself up out of bed like usual; he practically jumped out of bed with his heart pounding, terrified that he might miss his important math test.
Taking this test was critical to his grade, which he had worked hard to maintain throughout class, and his teacher had made it clear that anyone skipping class would fail the test automatically.Even though the test wasn’t truly life or death, Keith’s body responded almost as though being late was a direct threat to him. This response, where his body reacted with physical changes, like a pounding heart and a racing mind, is sometimes described as the fight or flight response because it helps us to cope with danger by preparing our body to either flee or attack.It might seem like a drag when you’re trying to stay calm to have your body react in such a stressed-out way, but if the threat had been a bear in Keith’s room about to attack him, of course his body’s responses would be essential to his survival.The autonomic nervous system provides the body with alerts to danger and supports the body to relax and function normally when not in danger. So on a normal day, instead of his autonomic nervous system making his heart pound when he wakes up, his body would instead be focused on things like digesting his breakfast. Thanks also to his autonomic nervous system, Keith will end up breathing no matter what, whether he remembers to breathe or not.
It may help to remember the name of the ‘autonomic nervous’ system by thinking about how many of the functions it regulates happen ‘automatically,’ like your heart beating, your breath going in and out on its own, and other processes that occur without you even having to think about them.As Keith finishes his test, his body will work to return to homeostasis, or normal functioning, thanks to his autonomic nervous system.
While the brain and spinal cord together make up our central nervous system, the peripheral nervous system communicates to other parts of the body.
The peripheral nervous system is made up of two major parts: the somatic nervous system and the autonomic nervous system. Somatic nervous system provides communication between the central nervous system and our organs and muscles. Sensory neurons and motor neurons play a role in how these messages are carried back and forth.
The somatic nervous system mainly deals with voluntary actions but also includes certain reflexes, like when we touch something hot.The autonomic nervous system provides the body with alerts to danger and supports the body to relax and function normally when not in danger. This system of the body helps us to be prepared for action when we are under threat or even perceive a threat. It also helps us to calm down when the threat has passed and get back to homeostasis, or normal functioning.
When you are done, you should be able to:
- Recall the function of the peripheral nervous system
- Name the two major parts of the peripheral nervous system
- Explain the roles of the somatic and autonomic nervous systems