Online Learning - Pembelajaran Sains Penghantaran Impuls Lewat Sinapsis - Pelajaran Sistem Saraf

Summary

This video explains how nerve impulses traverse synapses. When an impulse reaches the synaptic terminal, it increases the permeability of the presynaptic membrane to calcium ions (Ca2+), leading to the fusion of synaptic vesicles with the membrane and the release of neurotransmitters, like acetylcholine, into the synaptic cleft. These neurotransmitters bind to ion channels on the postsynaptic membrane, allowing ions like Na+ and K+ to diffuse, triggering a response in the receiving neuron. The neurotransmitter is then broken down by acetylcholinesterase and reabsorbed for reuse, completing the process of impulse transmission across synapses.

Takeaways

• 😀 When an impulse reaches the synaptic button, it triggers an increase in membrane permeability to Ca ions.
• 😀 The influx of Ca ions causes synaptic vesicles to fuse with the presynaptic membrane, releasing neurotransmitters into the synaptic cleft.
• 😀 One example of a neurotransmitter is acetylcholine, which binds to receptor channels in the postsynaptic membrane.
• 😀 Binding of acetylcholine opens ion channels, allowing Na+ and K+ ions to diffuse through the synapse.
• 😀 After neurotransmitter binding, the impulse continues to propagate in the neuron.
• 😀 Once the neurotransmitter has acted, it detaches from the receptor, closing the ion channels.
• 😀 Acetylcholine is broken down into choline and acetic acid by the enzyme acetylcholinesterase.
• 😀 The components of acetylcholine are then recycled into the synaptic vesicle for future use.
• 😀 The entire process described outlines how an impulse is transmitted across the synapse.
• 😀 This process of neurotransmitter release and reception is essential for nerve signaling and communication between neurons.

Q & A

What happens when an impulse reaches the synaptic button?

When an impulse reaches the synaptic button, it causes an increase in the permeability of the presynaptic membrane to calcium ions (Ca2+). This results in the influx of Ca2+ ions into the presynaptic neuron.

How does the synaptic vesicle release neurotransmitters?

The influx of calcium ions causes the synaptic vesicles to fuse with the presynaptic membrane, releasing neurotransmitters into the synaptic cleft.

What is one example of a neurotransmitter released during this process?

One example of a neurotransmitter released is acetylcholine.

How do neurotransmitters affect the postsynaptic membrane?

Neurotransmitters bind to receptor sites on ion channels in the postsynaptic membrane, causing these ion channels to open.

Which ions can diffuse through the opened ion channels in the synapse?

Sodium ions (Na+) and potassium ions (K+) can diffuse through the opened ion channels in the synapse.

What happens after the neurotransmitter binds to the receptor?

After the neurotransmitter binds to the receptor, the ion channels open, allowing ions like Na+ and K+ to flow through, and the impulse continues to propagate through the neuron.

What happens to the neurotransmitter once it has been received by the postsynaptic neuron?

Once the neurotransmitter has been received, it is released from the receptor, and the ion channels close.

What happens to the neurotransmitter after it leaves the receptor site?

The neurotransmitter is hydrolyzed into choline and acetic acid by the enzyme acetylcholinesterase.

What occurs to the components after the neurotransmitter is broken down?

After the neurotransmitter is broken down, choline and acetic acid are taken back into the synaptic vesicles for reuse.

How does this process contribute to synaptic transmission?

This process ensures that the impulse is transmitted across the synapse, with the neurotransmitter acting as a chemical messenger that facilitates the flow of information from one neuron to the next.