The past couple of weeks in the Neuro class have been tremendously interesting. We have been getting a great understanding of the ear and the anatomy. We have learned about the functions and importance of each part of the outer ear, middle ear and the inner ear. We went through the cochlear very thoroughly as well, from its anatomy to its specific function by joining with the vestibulocochlear nerve. We were able to see and discuss the axons involved and the different pathologies that cause deafness in one ear, or decreased partial hearing since some of the axons cross and thus does not have an indefinite impact on the patient’s hearing.
We also went over the COWS mnemonic which says cold water produces nystagmus beating opposite to the side in which water was introduced, while warm produces the nystagmus beating to the same side.
The class went over the different sections of the tongue and their taste sensations such as bitterness, sourness, saltiness and sweetness. We learned that the transduction of salt is mediated by the influx of sodium through the amyloid-sensitive sodium channels. We also saw that the sour taste is mediated by closure of voltage-dependent potassium channels. We saw that the sweet taste is mediated by activation of G proteins and adenylate cyclase, which increases the levels of cyclic adenosine monophosphate. We saw that the bitter taste activates a G protein that activates phospholipase C and generates inositol triphosphate.