Source: Video and Images Created by Amanda Soderlind
Welcome to this lesson today on sensory receptors.
Today we are going to be talking about the six different types of sensory receptors, and also discussing a little bit about what the purpose of the sensory system is.
Let's start by defining the sensory system. Our sensory system is a system that detects stimulus that we encounter around us, and then converts that stimulus into a nerve impulse, which is then sent to the brain or spinal cord, and produces a sensation or perception.
A sensation or perception. We're going to define what those mean. A sensation is an awareness of a stimulus that you encounter. And a perception is the understanding of what that sensation means. So if you think of any type of stimulus that you can encounter, a sensation is becoming aware of that stimulus, whereas a perception is understanding actually what that sensation means.
So in a nutshell, a stimulus will activate a receptor. And we're going to talk about the different types of receptors here in just a moment. A receptor we'll convert that stimulus to a nerve impulse, and then that nerve impulse will travel to the brain and be interpreted, depending on what it is.
So let's take a look at the six different types of sensory receptors that are in our body.
The first type we're going to talk about is a mechanoreceptor. So mechanoreceptors, their purpose is to detect changes in pressure, position, and acceleration.
So if somebody were to tap you on the shoulder, for example, the mechanoreceptors in your skin would detect that change in pressure, and you would actually be able to know that somebody was tapping you on the shoulder
Thermal receptors, as the name indicates, thermal means heat. So thermal receptors can detect temperature. Either heat or cold. We have thermal receptors in our skin that can detect changes in temperature. Heat or cold.
Nociceptors are pain receptors. These are free nerve endings that are found throughout our body, that help to detect tissue damage. If you were to prick yourself with a pin, for example, nociceptors would be the receptors that are sensitive to pain. So you would feel the pain because of those types of receptors throughout your body.
Chemoreceptors. If you think of the word chemo, it reminds you of chemistry or chemicals, so chemoreceptors detect chemicals that are dissolved in fluids or gases. They detect chemical that are dissolved in fluids or gases. And these really come into play with our sense of taste and our sense of smell. So chemoreceptors in our tongue or in our mouth allow us to taste the different foods that we're eating, and then chemoreceptors in our nose allow us to smell.
Osmoreceptors. If you think about osmo, water, Osmoreceptors detect changes in water volume, and therefore solute concentration in our body fluids. So they detect changes in water volume. And then when the water volume in your body fluid changes, it's going to it's going to affect the solute concentration in that solution, as well. So osmoreceptors are kind of keeping an eye on the water balance and solute concentration throughout your body.
Photoreceptors. Photo makes you think of light, so photo receptors detect visible light. And as you can imagine, these come into play especially with your eyes. You have photoreceptors, specifically rods and cones, in your eyes that detect different types of visible light.
This lesson has been an overview on the sensory system, and the six different types of sensory receptors throughout the body.
A system that detects stimuli, converts it to a nerve impulse and sends it to the brain to be interpreted.
The awareness of a stimulus.
The understanding of a sensation.
A sensory receptor that detects pressure, position and acceleration.
A sensory receptor that detects temperature changes (hot and cold).
A sensory receptor that detects pain.
A sensory receptor that detects chemicals dissolved in liquids or gases.
A sensory receptor that detects changes in water volumes and therefore changes in solute concentrations.
A sensory receptor that detects visible light.