Question

Identify I, II, III in the following image:

• A. I - Vesicle with neurotransmitters, II - Synaptic cleft, III- Postsynaptic receptor area.
• B. I - Vesicle with calcium ions, II- Extracellular fluid, III- Postsynaptic ion receptor area.
• C. I - Vesicle with macromolecules, II- Synaptic space, III- Postsynaptic receptor area.
• D. I - Vesicles, II- Extracellular fluid, III- Postsynaptic ion receptor area.

Answer 1

The correct option is A I - Vesicle with neurotransmitters, II - Synaptic cleft, III- Postsynaptic receptor area.

The brain consists of millions of neurons. Neurons communicate with each other at junctions called synapses. The neuron prior to the synapse is termed presynaptic neuron and the one subsequent to it is called the postsynaptic neuron. The end of the presynaptic neuron bears a swelling known as a synaptic knob. The synaptic knob has vesicles which contain chemicals called neurotransmitters. When an impulse arrives at the synaptic knob, the vesicles release neurotransmitters in the synaptic cleft. Here, the released neurotransmiiters bind to the receptors located at the postsynaptic neuron and transmit a signal.