So in our last lesson video, we talked about endocytosis and how it allows for entry into the cell. And so in this video, we're going to talk about the complete opposite of endocytosis, which is exocytosis and how exocytosis allows exiting from the cell. And so the EX in exocytosis is going to be very helpful for you all to remember exactly what exocytosis is about. And so exocytosis can be defined as vesicle fusion with the cell membrane, allowing the contents of the vesicle to exit the cell into the extracellular space or the outside space outside of a cell. And so you can think the EX in exocytosis is for the EX in exit and the EX in extracellular space.
Now there are many different types of molecules that can undergo exocytosis, but a few examples include hormones, neurotransmitters, and digestive enzymes. This is just a small subset of all the examples of molecules that can undergo exocytosis, allowing exiting from the cell. So let's take a look at our image down below to get a better understanding of this. And notice the inside of the cell is over here on the right-hand side and the outside of the cell is over here on the left-hand side. And so notice that, originally, these red molecules that you see here that are representing hormones are inside of a vesicle, inside of a membrane bubble here on the inside of a cell. And this membrane bubble, this vesicle, can start to fuse with the cell's plasma membrane here, and when that vesicle fully fuses, it can release the contents that used to be on the inside of the vesicle.
And so ultimately, what we get is the vesicle contents are being released into the outside of the cell, and so these contents are exiting the cell, via exocytosis. And so this here concludes our introduction to exocytosis and how it allows exiting from the cell, and we'll be able to get some practice applying these concepts as we move forward in our course. So I'll see you all in our next video.