Question

Diagram/Short answer assignment (2 pts ea) On the lines below, LEGIBLY write the names of the items that correspond to each of the letters (a-h). On the last two lines (i-), write the diagram letters that answer the questions. i) From which structure would an IPSP or EPSP be recorded? j) Where do calcium (Ca) ions enter the neuron?

Answer 1

a) Nerve impulse- Nerve impulse is the signal transmitted along a nerve fibre or axon. It is through nerve impulse that adjacent neurons communicate with one another.

b) Mitochondria- Mitochondria is the power house of the cell and within it lies the mitochondrion produce ATP. They concentrate within nerve ending and are responsible for providing energy for communication between nerves.

c) Synaptic vesicle- These are the sac like structures found in the synaptic knob, which contains neurochemicals.

d) Synaptic cleft/Synaptic gap- It is the microscopic fluid-filled gap between the synaptic knob of one cell and the surface or dendrites of the adjacent cell.

e) Receptor sites- Receptor sites are the holes found on the surface of the cell, which are shaped to fit some specific neurotransmitters only.

f) Post-synaptic (receiving) neuron- It is the neuron that receives the neurotransmitters from the pre-synaptic neuron after it has crossed the synaptic cleft, and experiences action potential if the neurotransmitter is strong enough.

g) Neurotransmitters- Neurotransmitters are the chemicals contained in the synaptic vesicles, which when released, transmit signals and enable neuro transmission.

h) Pre-synaptic (transmitting) neuron- A pre-synaptic neuron is a neuron that fires the neurotransmitters to transfer the signal to adjacent neuron, as a result of action potential reaching its axon terminal.

i) The answer is e) Receptor sites. It is through receptor sites, specifically voltage-gated calcium channels through which Calcium ions enter the neuron.

j) The answer is f) Post-synaptic (receiving) neuron. As we know, IPSP is Inhibitory post-synaptic potential & EPSP is Excitatory post-synaptic potential, and so, it is recorded from the post-synaptic neuron only.