Questions: What happens if there is an injury to the post synaptic tissue causing the neurotransmitter not to bind to the receptors of the post synaptic tissue? A. The action potential is not propagated B. The body sends out a different neurotransmitter C. The binding the neurotransmitter and receptor is not necessary D. The action potential will continue to be propagated

The answer is the first one (A): The action potential is not propagated.

Explanation for each option:

A. The action potential is not propagated - Correct. If the neurotransmitter cannot bind to the receptors on the postsynaptic tissue due to an injury, the signal cannot be transmitted across the synapse. This means that the action potential will not be propagated to the next neuron or muscle cell.

B. The body sends out a different neurotransmitter - Incorrect. The body does not automatically send out a different neurotransmitter in response to an injury at the synapse. Neurotransmitter release is specific to the type of synapse and the neurons involved.

C. The binding of the neurotransmitter and receptor is not necessary - Incorrect. The binding of the neurotransmitter to its receptor on the postsynaptic membrane is essential for the propagation of the action potential. This binding triggers the necessary changes in the postsynaptic cell to continue the signal.

D. The action potential will continue to be propagated - Incorrect. Without the binding of the neurotransmitter to the receptors, the action potential cannot be propagated across the synapse, so the signal transmission is halted.

In summary, if the neurotransmitter cannot bind to the receptors due to an injury, the action potential is not propagated.