Med-Surg - Nervous System, part 1: Introduction, Nervous System Functions and Components

Hi, I'm Cathy, with Level Up RN. This is the first video in our nervous system playlist, and I will be following along with our Level Up RN medical-surgical nursing flashcard deck. The purpose of this deck and of this playlist is to help you understand the most important concepts and facts you need to know to be successful in nursing school on your nursing school exams, on the NCLEX, and in nursing practice. If you have our flashcard deck, be sure to pay special attention to the bold red text because those are going to be the most important points for you to know.

In addition, with this video playlist, I'm going to start giving you guys little quizzes at the end of each of my videos to test your understanding of some of the key facts I will be covering in the videos. So definitely stay till the end of each of the videos so you can test your knowledge. I will be starting this playlist by going over some anatomy and physiology related to the nervous system. So just a high-level A&P review. The reason I'm going to do this is that if you can understand how a body system is supposed to work, you can think more critically and better understand what signs and symptoms to expect if that body system malfunctions. So I always find having a good grasp on the A&P really helps me to understand the disorders of a particular body system better.

Key functions of the nervous system include control over mobility, sensation, cognition, as well as many involuntary processes.

The two components of the nervous system include the central nervous system and the peripheral nervous system. Within the central nervous system, we have the brain and spinal cord. Within the peripheral nervous system, we have 12 cranial nerves, 31 pairs of spinal nerves, and the autonomic nervous system. And we will talk in more detail about the autonomic nervous system in another video.

The basic unit of the nervous system is the neuron. And the neuron is a cell that transmits impulses which are like messages within the nervous system. So each neuron produces a neurotransmitter, which is a chemical that will either enhance or inhibit the impulse.

So we have sensory neurons, which are afferent neurons. So these neurons control sensation, and they transmit messages from the peripheral nervous system to the central nervous system.

Then, we have motor neurons, which are efferent neurons. These control mobility, and they transmit messages from the central nervous system to the peripheral nervous system. So, for example, if I touch something hot, right, and I have that sensation of heat, a message will go through a sensory neuron from my peripheral nervous system to my brain in the central nervous system. My brain will process that message and then probably send a very quick message through an efferent neuron, right, a motor neuron, for me to move my hand.

So that's kind of the difference between afferent and efferent. And we have a Cool Chicken hint here on the card to help you remember. So afferent approaches the CNS, and efferent exits the CNS.

All right. So let's take a look at an illustration of a neuron so I can point out the different parts. Here's a beautiful picture of a neuron from our medical-surgical nursing flashcard deck.

So over here on the left, we have dendrites, which receive information from other neurons and transmit that message to the soma, which is the body of the neuron.

That impulse then travels down the axon.

And you'll notice surrounding the axon, we have the myelin sheath, which is a fatty substance that provides insulation and allows for faster transmission of that impulse. Now, later on in this video playlist, we're going to talk about multiple sclerosis, or MS, which is an autoimmune disorder that causes destruction of this myelin sheath, and therefore causes a number of issues that we will go into detail about.

The impulse then will travel all the way down here to the axon terminal, and at that point, neurotransmitters are released into the synapse, where they will bind with dendrites of their neighboring neuron.

All right. Are you guys ready for your first quiz of the nervous system? I have three questions for you. First question. What is the basic unit of the nervous system? The answer is the neuron. Question number two. The autonomic nervous system is part of the central nervous system. True or false? The answer is false. Question number three. What do you call the fatty substance that surrounds and insulates the axon in a neuron? The answer is the myelin sheath.

Okay. That's it for this quiz. I hope you found that helpful. In my next video, we will be talking about the brain. So definitely stay tuned for that.