Back to: ZOOLOGY 400 Level
Welcome to class!
Hello, bright star! I hope you’re doing well and feeling ready for another exciting step on this journey to becoming a top-level zoologist. Just like your brain helps you think, feel, and understand, today’s lesson will help you understand how the brain does all that magic. So get comfortable—we’re about to connect the wires of knowledge in your mind!
Neurons And Synaptic Transmission
Have you ever touched something hot and pulled your hand back immediately, even before you had time to think about it? That lightning-fast action is possible because of tiny, hardworking messengers in your body called neurons. They send and receive signals like a perfectly organised WhatsApp group chat—quick, smart, and efficient. Let’s look at how this works.
Neurons
Neurons are special cells that carry information around the body. You can think of them as the body’s “messengers” or “electric wires”. They help us do everything—see, smell, move, feel pain, think, and even sleep.
Each neuron has three main parts:
Cell body (soma): This is the control centre, like the brain of the neuron. It contains the nucleus.
Dendrites: These are short branches that receive messages from other neurons.
Axon: This is a long extension that sends messages away from the cell body to other neurons, muscles, or glands.
Some axons are covered with a myelin sheath (like an electric wire has plastic covering). This helps the messages move faster—just like 5G is faster than 2G!
Types of Neurons
Sensory neurons carry messages from the sense organs (eyes, skin, ears) to the brain.
Motor neurons carry messages from the brain to muscles or glands to cause action.
Relay neurons connect neurons within the brain and spinal cord.
Synaptic Transmission
Now, how do neurons pass messages from one to another? That’s where synapses come in.
A synapse is a small gap between the end of one neuron and the start of another. When a message (called a nerve impulse) reaches the end of a neuron, it cannot jump the gap directly. So, the neuron releases special chemicals called neurotransmitters into the gap.
These chemicals move across the synapse and pass the message to the next neuron. Once the second neuron receives the message, it continues the impulse along its axon. Think of it like passing a note in class—from one student to the next, quietly and quickly!
Real-life Example
Imagine you step on a sharp object in your compound:
Sensory neurons in your foot send a message to your spinal cord.
The relay neuron in your spinal cord processes it immediately.
The motor neuron tells your leg muscle to move away—fast!
This all happens in less than a second. That’s how sharp your nervous system is!
Summary
- Neurons are nerve cells that carry messages in the body.
- Each neuron has a cell body, dendrites, and a long axon.
- There are sensory, motor, and relay neurons with different functions.
- A synapse is a gap between neurons where chemical messages (neurotransmitters) are passed.
- Synaptic transmission allows the nervous system to send fast, accurate signals all through the body.
Evaluation
- What is the function of a neuron in the body?
- Name and describe the three parts of a neuron.
- Differentiate between sensory and motor neurons.
- What is a synapse, and how does synaptic transmission work?
- Give a simple example of when your body might use a reflex action involving neurons.
You’ve just unlocked another powerful secret of the human body! You’re becoming the kind of zoologist who doesn’t just memorise facts but understands how life truly works. Keep learning, keep believing—Afrilearn is always here to walk beside you on this journey to greatness. You’ve got this!