Okay. So for this one, we have this lovely depiction of dual innervation of the heart and we're going to be going through and labeling if these fibers are cholinergic, releasing acetylcholine, or adrenergic releasing norepinephrine or epinephrine. So, starting here in our sympathetic division with this preganglionic fiber, remember all preganglionic fibers in our entire autonomic nervous system are always going to be cholinergic, so it has to be a cholinergic fiber. And then you know what? While we're at it, let's go ahead and label this preganglionic fiber here on the parasympathetic side as well because it also has to be cholinergic. Alright.
So now jumping over here to the postganglionic fiber on the sympathetic side. This is going to be the fiber that is directly communicating with the effector organs. And to get that sympathetic activation, that fight or flight response going, we want to be putting some adrenaline into our system. So, this is going to be an adrenergic fiber. Then, scooching over here to the postganglionic fiber on our parasympathetic side now, this is our rest and digest. Right? So this does not want to be pumping any adrenaline into our body. This is going to be a cholinergic fiber as well. And you can see on our parasympathetic side both of our fibers are going to be cholinergic. So, it's pretty easy to remember that. So, really, just the one that's different is going to be that postganglionic sympathetic fiber, and that's going to be an adrenergic fiber.
Alright. So, there you have it, and I'll see you in the next one. Bye-bye.
