Tri-3, Wk1, Day 133 - Physiology!

Today we only had two classes due to many of the teachers being required to proxy National Boards test. The first class was Public Health and the 2nd class was Physiology II.

Some days I seem to be more productive than other days. I've done a lot of busy work but haven't really bitten into the Physio studying like I had hoped. I have gotten some new flashcards made up and updated another set I have going for physio. That class is worth 6 credit hours and meets every day of the week and for two hours on Wednesdays. The teacher is fantastic, as I've mentioned before but there is a heck of a lot of material coming at us every single day. I'm recording the classes with my Flip video recorder and have the first three hours of class burning was we speak to a DVD. The teacher, Iggy, rattled off a series of questions at the start of class and I was kind of like a deer in headlights and didn't have all the answers which always kind of concerns me. The sound quality of the recordings is a little weak when played back through the computer so I wasn't able to make out all the questions and answers but, once the DVD is made then I should be able to hear everything and complete a set of flashcards using FlashMyBrain.com to make sure I know everything he was asking.

Our first test in physio will be over the respiratory system so, we're just talking about the lungs, right? Yeah, pretty much but, the detail is much more than I ever realized. In addition to the three physio books I have Iggy has provided us with a 180 slide powerpoint presentation. I must say, however, that Iggy does the absolute best job of making use of powerpoints. Too many teachers sit behind their podium and ramble on endlessly about what is seen in each slide without ever interacting with their class and quickly switching from one slide to the next. Iggy takes as much time as necessary with each slide to make sure everybody has a fair opportunity to understand what's going on. This is not a class to be missed - ever.

In a more basic physio class one might learn that air is breathed into the lungs and eventually gets to little air sacs called alveoli and that's where oxygen is exchanged with carbon dioxide.

Yeah....

We might even get a neat bit of trivia concerning the lungs in that the surface area of all those little alveoli is about the size of a tennis court ...

Well....

True enough. But, how many layers of cells does gas have to pass through to go from say, the alvioli to a capillary? I believe there are four layers to be crossed, namely

1. alveolar epithelial wall of type I cells

2. alveolar epithelial basement membrane

3. capillary basement membrane

4. endothelial cells of capillary

four layers of respiratory membrane which are approximately 1/2 micron thick.

and with Type I alveolar cells, we should also know they go by the name of squamous pneumocytes and that they account for 95% of the alveolar surface.

Type II alcolar cells account for the other 5% of alveolar surface. They are also known as septal or great pneumocytes. They have the ability to differentiate into Type I pneumocytes to repair damaged pulmonary membranes and secrete alveolar fluid containing a surfactant - flashback to biochemistry - we talked about surfactants there also!

From the mouth or nose down to the depths of the lungs we need to know what's being passed along the way and what kinds of cells make up the various tubes along the way. As slide 38 in our powerpoint points out - we must note the changes in epithelium from stratified (oropharynx) to pseudostratified columnar (trachea), to columnar, to cubuoidal in the terminal bronchioles, to simple squamous in the respiratory zone.

Huh?

I guess it's more acceptable for a reader to say huh as opposed to someone that's actually taking the class. I'll just take each part piece by piece and we'll get to know this better together ;)

epithelium - skin! - this is any tissue composed of cells that line the cavities and surfaces of structures throughout the human body :) (thank you wikipedia)

oropharynx - the area from the soft palate on the roof of your mouth to the epiglottis or hyoid bone (depending on your resource), the word pharynx also means throat.

pseudostratified - with a word like "pseudo" in it, you know it's gotta be fake! and it is - stratified cells are layered but pseudostratified cells just look like they are layered but, in reality each one connects to a basement membrane.

trachea - this is better known as the windpipe. This runs from the larynx (voicebox) down to the 5th thoracic vertebrae and in front of the esophagus (food tube to stomach)

well ...this keeps getting more and more in depth the more I look at things and I'm getting tired.

like I mentioned, this stuff is detailed right down to the individual cells. I'll keep chugging along ...

I think for today's picture I'll put up a nice picture of the lungs :)

Tomorrow should be pretty cool. I'll have my first class of Pathology along with Public Health and the omnipresent physio class :) then Micro II, along with Micro II Dry Lab. It sounds like we'll be watching movies twice a week for our Micro II Dry Lab - every Wednesday and Friday. Certainly not a difficult thing to do. Actually, the first show we were watching this past Wednesday was pretty interesting. hmm, we also have a wet lab for microbiology where we'll get to spend more time playing with bacteria :)