Also in this week's column:
- Was human skin really used in book binding?
- Does thumb-sucking run in families?
- Will eating crusts make your hair grow curly?
How do I taste things?
This is the work of your gustatory taste receptor cells (TRCs). Taste buds nestle inside the tiny bumps (papillae) you feel on your tongue. Each taste bud is a tiny sensory organ.
Located within your taste buds are TRCs. TRCs detect sweet, sour, salty, and bitter. There is also a less well-known and even less well understood taste they detect called umami. Umami occurs in response to monosodium glutamate (MSG).
Each TRC specialises. Some sense sweet, others sense sour, and so on. Whatever is sensed is signaled to the brain via two nerves. One is part of the fifth facial nerve and called the chorda tympani. The other is a nerve also used in swallowing and called the glossopharyngeal (rolls right off the tongue, doesn't it?). When the brain receives a signal from the TRCs, we judge something to be sweet, sour, salty, bitter, or perhaps slightly differently, umami.
Why is it that when I have a blocked nose I can't taste things? I'm eating really rich chocolate but I can barely taste a thing!
Asked by Xander Winson of Derby, United Kingdom
Some of the sensations commonly assigned to the sense of taste are in reality examples of the sense of smell. Many spices have relatively little taste, but affect the sense of smell powerfully. When your sense of smell is hampered by a nose cold, you can't taste food as well either.
If my mouth is dry, why can't I taste very well?
A substance can only be tasted if dissolved in water or saliva. If the mouth is dry, you can't taste very well at all.
Stephen Juan, Ph.D. is an anthropologist at the University of Sydney. Email your Odd Body questions to email@example.com