Book Link 19 Cells of the Nervous System
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By the end of this section, you will be able to:
- Identify the basic parts of a neuron
- Describe how neurons communicate with each other
- Explain how drugs act as agonists or antagonists for a given neurotransmitter system
Key Definitions
Neuron: A neuron is a special cell that sends messages to other cells in the body, like muscles or other nerve cells. It’s a basic building block of the nervous system. A neuron has three main parts:
- 1. Cell body (soma): This is like the control center of the neuron.
- 2. These are like the arms of the neuron that receive messages from other neurons.
- 3. Axon: This is like the long tail of the neuron that sends messages to other neurons, muscles, or glands.
Agonist: An agonist is a chemical or drug that attaches to a receptor and makes it work. It’s like pushing a button to create a specific effect in the body.
Antagonist: An antagonist is a chemical or drug that attaches to a receptor and stops it from working. It’s like blocking a button to prevent a specific effect in the body.
Neurotransmitter system: A neurotransmitter system is a group of cells that work together to control specific processes in the body using certain chemicals called neurotransmitters. These systems help the brain communicate within itself and with the rest of the body.
How Neurons Work
In Simple Terms
In all mammals, neurons send signals to communicate with other parts of the body. However, in humans, the brain has evolved to be more complex, allowing us to do things like speak, think, and solve problems. This makes human neurons different from those in other mammals.
A More Complete Explanation
Neurons work in a similar way in all mammals. They transmit electrical and chemical signals to communicate with other neurons, muscles, or glands. However, in humans, the brain has evolved to be more complex, allowing for higher cognitive functions such as language, reasoning, and problem-solving.
This increased complexity and specialization of certain brain regions set human neurons apart from those of other mammals. Additionally, the sheer number of neurons and the intricate connectivity within the human brain distinguish human neuron function from that of other mammals.
Medicine and Neurons
The endocannabinoid system and its receptors provide a good example of how drugs can affect neurotransmitter systems. For example, certain medications can help reduce the frequency and severity of seizures by acting as antagonists for molecules that influence seizures.
All mammals, including humans, have an endocannabinoid system that regulates functions such as mood, memory, appetite, and pain sensation. This system consists of endocannabinoids, cannabinoid receptors, and enzymes involved in their synthesis and breakdown. It plays a crucial role in maintaining the body’s internal balance.
CB1 and CB2 receptors are present in all mammals, including humans. CB1 receptors are mainly found in the brain and nervous system, while CB2 receptors are more commonly found in the immune system and other peripheral tissues. These receptors play a key role in mediating the effects of cannabinoids on various physiological processes.
Summary
The section explains how our brain cells, called neurons, work and communicate with each other. It also talks about how certain chemicals and drugs can affect these communications. It mentions how human brain cells are different from those of other animals because they allow us to do things like talk and solve problems.
The text also discusses a system in our body that affects things like mood and pain, and how some medicines can help with conditions like seizures by acting on this system. Overall, it tells us how important these systems are for keeping our bodies working well.