PHGY 209 Lecture : PHGY 209 CNS- cognitive motor.doc

• School: McGill University
• Department: Physiology
• Course: PHGY 209
• Professor: Ann Wechsler

Document Summary

In our tongue, there is about 10 000 taste buds (on papillae). Protons (h+) usually block ion channels or interfere w/ their function (ex. take the place of na+ in sodium channels or block k+ in potassium channels). That"s why licking salt and then taking tequila removes the salty sense (acid interfere w/ salty sensation receptors). Bitter sensation is a protection to prevent us from eating the wrong thing. Umami is a flavor enhancement used in a lot of food these days. We can differentiate about 10 000 odors, against 5 gustative modalities. There are only roughly 1000 different receptors in olfactory system. Odorant molecules have different degree of affinity w/ each so we can distinguish 10 000 w/ 1000 receptors. Olfactory sensation doesn"t go to the thalamus like other sensory systems. The limbic system is involved in a lot of emotional responses so olfaction has a direct connection w/ the part of brain regulating emotions.