Cutaneous Sensory Afferents

00:00 Cutaneous Sensory Afferents.

00:04 Cutaneous sensory afferents are a large group of nerves that will send a lot of different information from the skin to the brain.

00:13 As you can imagine, there's a lot of information that can be garnered from our organ that is most externally placed.

00:21 It is interacting with the environment all the time.

00:25 And you'll need to know things like, well is it going to be a high amount of forced being impressed against me? Is it too hot? Is it too cold? All these things can be tell by the cutaneous sensory afferents.

00:38 So let's go through some of the nerve classes that are associated with the skin afferents.

00:46 Skin tactile receptors are known as A beta.

00:51 And these have a fairly slow conduction velocity, although they are still myelinated about 33 to 75 meters per second.

01:00 A delta fibers, these are pain and temperature sensors.

01:05 These also have a fairly slow conduction velocity, 5 to 30 meters per second.

01:11 But again, these are still myelinated neurons.

01:14 And finally, we have our slowest class, and that's class C.

01:19 These involve things like pain, temperature, itch receptors.

01:23 These are all very slow unmyelinated neurons about ½ to 2 meters per second.

01:31 So if we compare the A beta, A delta, and Cs to the muscle spindles and the golgi tendon organs, you can see that the skin conduction velocities are very slow in comparison.

01:43 So the information doesn't in travel back quite as fast.

01:46 But again, you have a lot more surface area that might be involved.

01:50 So you could get a lot more signals but just not as fast.