The Nervous System: The Neuron (Nerve Cell)

Summary

This lesson delves into the neuron, the primary cell of the nervous system, highlighting its structure and function. The neuron's cell body, dendrites, axon, and synapses are detailed, explaining how they facilitate communication across the body. The video also explores the myelin sheaths' role in speeding up signal conduction and the significance of the nodes of Ranvier. It concludes by discussing how neurons form networks and transmit messages via synapses, allowing us to perceive our surroundings.

Takeaways

• 🧠 The neuron is the primary cell of the nervous system, responsible for communication within the body.
• 🌳 The neuron has a cell body, or soma, which contains the nucleus.
• 🌿 Dendrites are branch-like structures that receive chemical and electrical stimuli.
• 📡 The axon is the neuron's longest extension, facilitating communication across long distances.
• 🔗 The axon hillock is the junction where the axon connects to the soma.
• 🛡 Myelin sheaths are protective fatty tissues that surround the axon and speed up signal conduction.
• 🏁 Nodes of Ranvier are gaps in the myelin sheaths that aid in signal conduction and nutrient exchange.
• 🌐 Axon terminals are the branching ends of the axon that form connections with other neurons.
• 🔄 Neurons form a network through synapses, where messages are transmitted between neurons.
• 🌐 Synaptic cleft is the junction where neurotransmitters are released and received, facilitating message transmission.
• 🌐 The nervous system interprets messages from neurons as sensations, allowing us to perceive the world.

Q & A

What is the primary cell of the nervous system?

The primary cell of the nervous system is the neuron.

What is the function of the neuron?

The neuron allows the nervous system to communicate with the rest of the body by transmitting messages across relatively long distances.

What is the cell body of a neuron also known as?

The cell body of a neuron is also known as the soma.

What are dendrites and what is their function?

Dendrites are tree-like branches that extend off of the soma and are used by the neuron to detect both chemical and electrical stimuli.

What is the longest extension from the soma of a neuron?

The axon is the longest extension from the soma of a neuron.

What is the role of the Axon hillock?

The Axon hillock is the junction that connects the axon to the cell body.

What are Myelin Sheaths and how do they help the neuron?

Myelin sheaths are sections of fatty tissue that protect the axon and help speed up signal conduction along the axon.

What are the gaps between myelin sheaths called?

The gaps between myelin sheaths are called the Nodes of Ranvier.

What is the function of the Nodes of Ranvier?

The Nodes of Ranvier aid in signal conduction and allow nutrients and waste to enter and leave the axon.

How do neurons communicate with each other?

Neurons communicate with each other through the Synapse or Synaptic cleft, which is the junction between one neuron's axon terminals and another neuron's dendrites.

What happens at the Synapse during message transmission?

At the Synapse, chemical and electrical neurotransmitters are released and picked up by the dendrites of the recipient nerve cell.

How does the body interpret the messages passed by neurons?

The body interprets the messages passed by neurons as sights, sounds, aromas, and other sensations that allow us to observe the world around us.

Outlines

00:00

🧠 Introduction to Neurons

This paragraph introduces the neuron as the primary cell of the nervous system, emphasizing its role in communication between the nervous system and the rest of the body. It outlines the neuron's structure, including the cell body (soma), dendrites, axon, axon hillock, myelin sheaths, nodes of Ranvier, and axon terminals. The paragraph also sets the stage for discussing how neurons form a network and transmit messages.

Keywords

💡Neuron

A neuron is the primary cell of the nervous system, responsible for transmitting information throughout the body. It is the central focus of the video, as it discusses the neuron's structure and function. The neuron's ability to transmit messages is crucial for the nervous system to communicate with the rest of the body, which is the main theme of the video.

💡Cell Body (Soma)

The cell body, also known as the soma, is the central part of the neuron that contains the nucleus. It is the control center of the neuron, housing the cell's genetic material. In the script, the cell body is mentioned as the starting point for understanding the neuron's structure.

💡Dendrites

Dendrites are the tree-like branches that extend from the soma. They play a critical role in receiving signals from other neurons. The video explains that dendrites are used to detect both chemical and electrical stimuli, which is essential for the neuron's function in the nervous system.

💡Axon

The axon is the longest extension of the neuron and serves as the primary communication pathway. It can be quite long, up to a meter, and is vital for transmitting signals from one neuron to another. The video highlights the axon's role in the neuron's communication process.

💡Axon Hillock

The axon hillock is the junction where the axon connects to the cell body. It is a crucial region for the initiation of action potentials, which are electrical signals that travel along the axon. The video mentions the axon hillock in the context of the neuron's structure.

💡Myelin Sheaths

Myelin sheaths are protective layers of fatty tissue that cover the axon. They play a significant role in speeding up the conduction of electrical signals along the axon by insulating it. The video explains that these sheaths are essential for the efficient functioning of the nervous system.

💡Nodes of Ranvier

Nodes of Ranvier are the gaps between myelin sheaths. They are important for the saltatory conduction of nerve impulses, which allows for faster signal transmission. The video mentions these nodes as part of the axon's structure that aids in signal conduction.

💡Axon Terminals

Axon terminals are the branching ends of the axon that form connections with other neurons. They are essential for the release of neurotransmitters, which is how neurons communicate with each other. The video discusses axon terminals in the context of forming a nerve cell network.

💡Synapse

A synapse is the junction between the axon terminals of one neuron and the dendrites of another. It is the site where information is transferred between neurons through the release and reception of neurotransmitters. The video explains that the synapse is critical for message transmission in the nervous system.

💡Neurotransmitters

Neurotransmitters are chemical messengers that transmit signals across a synapse from one neuron to another. They play a vital role in the communication between neurons and are essential for the functioning of the nervous system. The video mentions neurotransmitters in the context of message transmission at the synapse.

💡Nerve Cell Network

A nerve cell network refers to the interconnected web of neurons that work together to process and transmit information. The video discusses how individual neurons come together to form this network, which is essential for the nervous system to interpret and respond to various stimuli.

Highlights

Introduction to the neuron as the primary cell of the nervous system.

Neuron's role in allowing the nervous system to communicate with the rest of the body.

Key features of the neuron's structure for transmitting messages.

Description of the Cell Body or Soma, which houses the cell nucleus.

Function of dendrites in detecting chemical and electrical stimuli.

The axon's role as the primary communication pipeline of the neuron.

Explanation of the Axon hillock as the junction connecting the axon to the cell body.

The protective and conductive role of Myelin Sheaths on the axon.

The function of Nodes of Ranvier in signal conduction and nutrient exchange.

Description of Axon Terminals and their branching structure.

How neurons form a nerve cell network for message transmission.

The Synapse as the junction for message transmission between neurons.

The process of chemical and electrical neurotransmitters being released and picked up at the synapse.

Interpretation of messages by the central nervous system as sights, sounds, aromas, and other sensations.

Conclusion of the discussion about the neuron's structure and function.

Thank you note for watching the lesson on the nervous system.

Transcripts

Welcome back to our lesson on the nervous system.

In this video, we will talk about the primary cell of the nervous system,

the neuron

We will talk about the structure of neurons

and also how they come together to form an entire network of nerve cells.

Great so let’s begin.

The neuron is a very fascinating and vital portion of the nervous system

because it allows the nervous system

to communicate with the rest of the body.

The structure of the neuron offers key features to help it to transmit messages

across relatively long distances.

To begin,

the Neuron has a Cell Body,

which is also known as the Soma,

and which houses the cell nucleus.

Next, are the dendrites,

which are tree-like branches that extend off of the soma.

These are used by the neuron

to detect both chemical and electrical stimuli.

In the center of the neuron is the axon.

The axon is the longest extension from the soma

and can be up to a meter in length.

It serves as the primary communication pipeline

from one end of the neuron to the other.

The Axon hillock is the junction

that connects the Axon to the cell body.

Covering the axon are Myelin Sheaths.

Myelin sheaths are sections of fatty tissue

that help to protect the axon

and also help to speed-up signal conduction

along the axon.

The gaps between myelin sheaths

are called the Nodes of Ranvier.

These also aid in signal conduction

and they also allow nutrients & waste

to enter and leave the axon.

Finally, at the end of the axon, are extensions that

branch off to form several Axon Terminals.

Now that we’ve covered

the structure of the neuron,

let’s talk about how neurons

come together to form a nerve cell network.

Remember, neurons are supposed to

send messages to each other,

but how exactly does this happen?

Message transmission happens at the Synapse,

or Synaptic cleft,

which is the junction between one neurons axon terminals and another neuron’s dendrites.

This is the special area,

where chemical and electrical neurotransmitters

are released, and picked are up by the dendrites

of the recipient nerve cell.

As neurons pass information to central nervous system,

our body then interprets these messages as sights,

sounds, aromas, and other sensations that allow us observe the world around us.

This concludes our discussion of the neuron.

Thank you for watching.