Taste (Nursing)

00:02 We also have a closely related special sense called taste, when there are typically considered five primary tastes sour, sweet, bitter, salty, and savory or umami.

00:18 And there's been a lot of debate back and forth about different portions of the oral cavity sensing these different tastes more than others.

00:27 Although it really does seem that taste buds can really sample all of these pretty much everywhere in the mouth.

00:35 So what are the taste receptors? Well, the taste receptors are the taste buds.

00:40 And as you can see here in a very zoomed in portion of the tongue, they tend to live in these little furrows or grooves that can be located mostly in the tongue, although there are some elsewhere in the oral cavity.

00:54 And so they're special little areas on the epithelium that line the tongue in between these little bumps.

01:02 And these little bumps sometimes get special names as papillae.

01:07 So we have these large ones here called the Circumvallate papillae.

01:11 And then many, many smaller ones, such as the Foliate papillae, and Fungiform papillae.

01:17 As well as other papillae that don't actually have taste buds, which are the Filiform papillae.

01:25 When it comes to taste, the pathways are actually a little bit more complicated than you might expect.

01:31 And the key landmark is the anterior two thirds versus the posterior third of the tongue.

01:38 Due to some very complicated embryological development, the facial nerve or cranial nerve VII, is actually what will provide taste sensation to the anterior two-thirds of the tongue.

01:54 The posterior third of the tongue will actually be carried out by the glossopharyngeal nerve or cranial nerve IX.

02:02 And there is a little bit of taste beyond the tongue further back into the pharyngeal area that will be carried out by cranial nerve X, which is the vagus nerve.

02:16 And they'll all go back to what's called the gustatory nucleus.

02:20 Gustatory is our fancy word for taste, just like olfaction is our fancy word for smell.

02:26 And eventually work its way back up to the thalamus for the primary gustatory area for processing of taste.