In this video, we're going to be learning how to classify reflexes. So there are actually many ways to do this, but we're going to cover the 3 most common. So first and foremost, we can classify reflexes developmentally. Basically thinking about whether this is something we are born with or something that we acquire over time. So we can have innate reflexes, which are genetically programmed during natural development. For example, if you were to startle a newborn baby, they're going to throw their arms out in the air. That is called a startle reflex and it is innate. We are born with that reflex, but we can also have acquired reflexes, and these are complex learned motor patterns. For example, if you were driving your car and you saw an accident happen right in front of you, you probably hit the brake before you even had to think about it. That is an acquired or learned reflex.

Now, we can also classify reflexes based on their response type. So we can have somatic reflexes which use our somatic nervous system and these are rapid involuntary motor responses to a stimulus and those will involve our musculoskeletal system. And, we can also have autonomic or visceral reflexes and these use our autonomic nervous system And these will be non-skeletal responses that get carried out in internal organs. So smooth muscle, cardiac muscle, glands, all of that stuff is covered under visceral reflexes or autonomic reflexes.

And then finally, we can organize them based on their the complexity of the neural pathways that they follow. So we can have monosynaptic reflexes, which as the name implies, involves a single synapse during integration. So, we will have our sensory neuron and our motor neuron and just one synapse there, and we can also have polysynaptic reflexes which again as the name implies involve multiple synapses during integration. Here we would have our sensory neuron, at least one interneuron, and a motor neuron, and you can see we have multiple synapses there. Generally speaking, most reflexes are polysynaptic. There are actually relatively few examples of monosynaptic reflexes in the human body, so just keep that in mind as we move forward.

Now, we're going to go through just a couple commonly known reflexes and just kind of show you how we can categorize them developmentally, based on their response type, and based on their complexity. And just a quick heads up, I don't expect you to know if any of these are monosynaptic or polysynaptic, so I'll just be giving you those answers. But we can kind of work through the development and response type together. Alright, so without further ado, we're going to start with our knee jerk reflex, one of our most well-known reflexes. This is when you're sitting at your doctor's office, they whack your knee with the little hammer, and your leg pops up. That is our knee jerk, and developmentally speaking, this is not something that you have to learn. Right? This is innate. Your doctor's probably been doing this to you since before you can even remember. Right? And in terms of the response type, this is involving our musculoskeletal system, so it must be a somatic reflex. And in terms of the complexity, these are actually monosynaptic. So this is one of the best examples of a monosynaptic reflex in the human body and we're actually going to have a whole video on these coming up so stay tuned for that. Now next, we have our Babinski reflex, which if you've never heard of it, is when you take a newborn baby's foot and you stroke the bottom of their foot and it makes them fan out their little toes. It is the cutest thing in the world. But if it's happening in a newborn baby developmentally, it's probably innate. Right? So these are innate reflexes, and in terms of the response type these are also using our musculoskeletal system so they're going to be somatic. And these are polysynaptic. Again, most reflexes are polysynaptic just in general.

And finally, we have conditioned taste aversion. So this is when, if you've ever had a stomach bug, you know how sometimes whatever food you ate right before you got sick, even if it's not what made you sick, afterward, the idea of that food is, like, repulsive to you. Just thinking about it can make you feel nauseous or make you want to vomit. That is conditioned taste aversion. And so developmentally, this is something that you have learned. Right? Your brain has learned to associate that food with the feeling of being sick. So this is an acquired reflex. And in terms of the response type, this is not involving our musculoskeletal system. Right? This is involving a feeling of nausea in our internal organs. So this is autonomic, and these are also polysynaptic.

Alright, so those are some examples of reflexes and that is how we can categorize different types of reflexes. So now that you have a good handle on reflexes more generally, we're going to start going over some types of reflexes in a bit more detail in our upcoming videos. So I'll see you there.