Get Answers to all your Questions

header-bg qa

What is the role of calcium ions in the transmission of impulses at a chemical synapse?

Option: 1

Calcium ions bind to the neurotransmitter, causing it to be released into the synaptic cleft.

Option: 2

Calcium ions trigger the fusion of the vesicles containing neurotransmitters with the presynaptic membrane.

Option: 3

Calcium ions bind to the receptors on the postsynaptic membrane, allowing the neurotransmitter to bind.


Option: 4

Calcium ions break down the neurotransmitter, terminating the synaptic transmission.

Answers (1)


At chemical synapses, calcium ions are essential for the transmission of impulses. Voltage-gated calcium channels open when an action potential reaches the presynaptic terminal, allowing calcium ions to enter the cell. The presynaptic membrane and the vesicles containing neurotransmitters fuse as a result of the calcium ion inflow. As a result of this fusion, neurotransmitters are released into the synaptic cleft where they bind to receptors on the postsynaptic membrane to produce a chemical signal that may cause ion channels in the postsynaptic neuron to open or close, altering the membrane potential and possibly result in an action potential. The correct answer is option 2 because Calcium ions cause the presynaptic cell to release neurotransmitters.


Posted by


View full answer

NEET 2024 Most scoring concepts

    Just Study 32% of the NEET syllabus and Score up to 100% marks