Welcome biologists, this is a session where we're going to be taking a look at sensory receptors and their role as transducers. So the main role of a sensory receptor is to detect some kind of stimuli and that is detected by a receptor. The receptor then sends a nerve impulse along the sensory neuron, sensory neuron then sends this to the relay neuron, a relay neuron to the motor neuron which is connected to an effector which triggers some kind of a response and the effector is normally a muscle or a gland. Now there are different kinds of receptors within the body. Here are just a small handful of them.
I'm not going to read through them all but as you can see here this is the stimuli that they detect and what they're converted into. So the electrical impulses are the nerves. So as you can see here all of the receptors here will change the energy from one form into another and this makes each of these receptors here a transducer.
So a transducer is something that converts. energy from one form to another which is what the majority receptors do within our body. So that's basically what our receptor is and how it acts as a transducer but now we need to look specifically at what this parsinian corpuscle is and how that works. So a parsinian corpuscle this is found within your skin and it detects pressure changes. Now the way in which it does this is as the outer layers here become squashed due to the pressure changes it causes gaps or spaces to appear between the phospholipids that make up these membranes.
This then opens up sodium channels and sodium rushes in to the nerve ending here it opens the sodium channels up in this nerve ending and the sodium rushes in along its electrochemical gradient generating an action potential. Now anything here in a red box is taken directly from the MART scheme and I know you might not know too much about the use of sodium within nerves at this point, but you'll learn more about that within the next two or three videos. So for the moment, just bear that in mind.
You might not know this in a lot of detail for now, but that's absolutely fine. You'll come to know that really, really well. So it might be worth revisiting this parsing in corpuscle after you've learned more about how nerves function and work. So that's everything we need to know for today. Just remember in your explanation to use good scientific and biological terminology.
not it, they, amount or size. Guys, good luck with your exams and all the best.