A&P II

So I suppose it's time to start getting back into the swing of things...how quickly a week can fly by! OK, so in a continuation of the special senses, I have to repeat that I find the fact that senses are based on perceptions very unscientific. It's sorta funny how everything else we learn about has some sort of accepted theory or is agreed upon for the most part, yet senses are not.

I remember when I was in middle school we were taught about the taste map, where in the back of the tongue were the sour/bitter receptors, the sweet were in the front and the salty were on the edges. I just now found out that that is a bunch of malarkey. All of these taste sensations arise from all regions of the oral cavity. The "mouth map" is a myth, generally attributed to the poor translation of a German text, and has been taught in North American schools since the early twentieth century. Actually, very slight regional differences in sensitivity to compounds exist, though these regional differences are subtle and do not conform exactly to the mythical tongue map. Individual taste buds (which contain approximately 100 taste receptor cells), in fact, typically respond to compounds evoking each of the four basic tastes.

Taste and smell are combined to mean flavor. Other factors include the food's smell, its texture, detected by mechanoreceptors, and its temperature, detected by thermoreceptors are all inputs to our brains to sort and merge to form the flavor we taste.

In Western culture, the concept of basic tastes can be traced back at least to Aristotle, who cited sweet, bitter, succulent, salt, pungent, harsh, astringent, and acid as tastes. The ancient Chinese Five Elements philosophy lists slightly different five basic tastes: bitter, salty, sour, sweet, and spicy. Japanese and Indian cultures each have their own sixth taste in addition to the basic five.

The receptors for all known basic tastes have been identified. The receptors for sour and salty are ion channels (H+ and Na+ respectively), while the receptors for sweet, bitter, and umami belong to the class of G protein second messenger systems (sounds familiar doesn't it).

Well, that's what I learned today...see you all Tuesday!

A & P II

So let me start by saying that I didn't think that "quiz" was easy, and the take home took way longer than I had anticipated. The information available on the internet is sadly disorganized. I found it very difficult to find the information regarding the neurotransmitter questions. I realize that neurotransmitters are a realitively new topic, however with the massive amounts of antipsychotic medications being perscribed, the information should be made more accessible to the general public.

I did find the prevelence of strokes and brain tumors astounding though. I did not know that brain tumors account for 1.4 % of all cancers, 2.4 % of all cancer deaths, and 20–25 % of pediatric cancers. There are 13,000 dealths a year that are attributed to brain tumors. Why is it that tumors are commonly found in the posterior cranial fossa in children and the cerebral hemispheres in adults. What would cause that?

I have been a CPR/First Aid trainer for years now, and I was taught to use F.A.S.T. (face, arm, speech, time) when detecting symptoms of a stroke. Time being the most important...to denote the time you started to see symptoms. This helps the doctors determine how severe the damage may be.

Well, see you all on Tuesday.
Aimee