What's the difference between a synapse and a synaptic cleft? I've looked at the definition that my textbook gives me but they seem sort of similar. So, are these synonyms or are they supposed to be different? If they are different when would it be appropriate to use one of them as opposed to the other? If anyone could show two different sentences where it would be most appropriate to use the two terms, it would be greatly appreciated!

IIRC, the synapse refers to the whole structure, including the tips of the cells, while the cleft specifically refers to the gap between them.

That's it.

Synapse = presynaptic membrane (including membrane channels, vesicles etc.), synaptic cleft and post-synaptic membrane (including membrane channels etc.)

 

Synaptic cleft = synaptic cleft.