Question Video: Describing the Role of Synaptic Vesicles | Nagwa Question Video: Describing the Role of Synaptic Vesicles | Nagwa

Question Video: Describing the Role of Synaptic Vesicles Biology • Second Year of Secondary School

What is the role of synaptic vesicles in the presynaptic neuron? [A] To store neurotransmitters [B] To store enzymes [C] To attach to receptor sites on the postsynaptic membrane [D] To stimulate the influx of sodium ions

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Video Transcript

What is the role of synaptic vesicles in the presynaptic neuron? (A) To store neurotransmitters. (B) To store enzymes. (C) To attach to receptor sites on the postsynaptic membrane. (D) To stimulate the influx of sodium ions.

To answer this question, let’s start by reviewing key components of the synapse, which comprises the presynaptic neuron. The junction of two neurons in communication is called the synapse. It is usually composed of three parts: the axon terminals of the presynaptic neuron; the synaptic cleft; and the postsynaptic cell, which can be the dendrites of a postsynaptic neuron, a gland, or a muscle fiber. Our capacity to think, learn, memorize, and move depends crucially on the strength and number of our synapses. This is because synapses play a major role in the transmission of nerve impulses.

To transmit the nerve impulse from one neuron to the next, the presynaptic neuron must release specialized chemical messengers called neurotransmitters, which are shown here in green. These neurotransmitters are able to cross the synaptic cleft and carry the message of the nerve impulse to the next neuron. To make sure that neurotransmitters are ready to transmit on demand, they’re stored in special packages called synaptic vesicles, which are concentrated at the ends of presynaptic neurons.

As the nerve impulse reaches the end of the presynaptic neuron, it stimulates an influx of calcium ions into the presynaptic neuron. The influx of calcium ions causes the synaptic vesicles to fuse with the membrane of the presynaptic neuron and release neurotransmitters into the synaptic cleft. The neurotransmitters will travel unidirectionally to the receptors on the postsynaptic membrane, which open sodium ion channels and generate the next nerve impulse.

With these key facts in mind, let’s take a look at our possible answer choices. The role of synaptic vesicles in the presynaptic neurons is to store neurotransmitters.

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