Unit 5 Reflection

There are many organs in the body that each regulate unique functions using hormones specific to itself. In Unit 5, we explored the major(ly packed) organs of the digestive system- see http://mesocy.blogspot.com/2016/01/the-digestive-system-lab.html- and also the wide range of hormones and their effects on counteracting conditions adverse to homeostasis.

Fasting State Poster

For example, we focused on the concentration of glucose in the blood, AKA blood sugar, and how it was affected by the diet that people consumed. See: http://mesocy.blogspot.com/2015/10/blood-pressure-virtual-lab.html
We differentiated it into three states: the Fed State, where a meal was just eaten; the Fasting State, where a meal has not been consumed for a few hours; and the Starvation State, in which the body's cells undergo autophagy, breaking down its proteins into energy sources in a desperate attempt to keep the cell functioning.





States occur in response to the concentration of blood sugar in the bloodstream. Since humans' blood sugar levels must be constantly maintained, as long as nutrients from the digestive system are anticipated, the pancreas will release insulin, which basically functions as a signal to remove glucose from the circulatory system as fast as possible. It signals a storage of glucose as a glycogen polysaccharide inside the liver and increase the intake of glucose by the body's various cells (mostly fat and muscle though) through promotion of a specific membrane protein, called GLUT-4. Usually GLUT-4 is stored inside the cell on a vesicle membrane, but in the presence of insulin, the vesicle fuses with the cell membrane and thus disseminates its proteins into the surrounding lipid bilayer. Now, when the blood sugar level decreases to a point where it is too low, the pancreas releases glucagon instead. Glucagon causes the stored glycogen polysaccharides to be broken down in the process of glycogenolysis for glucose, which can then be used for cellular respiration and, thus, energy. These ups and downs are simply represented on the left as double ringed, negative feedback loops.


I had a tough time in this unit memorizing all of the different organ, substance, and process names, and thus couldn't fulfill my objective of scrabbling together a nine hour sleep schedule. However, I have made progress on my SMART goal of studying, and have eliminated a few weaker strategies (e.g. outline format).
see: http://mesocy.blogspot.com/2016/01/smart-goals.html
I really would like to know why many organs have almost unintelligible, unrelated names, and why not change them, like the GLUT-4 protein. The number four seems to correspond with the affinity the integral transport protein has for insulin, and the GLUT portion is reminiscent of glucose-transferring protein. Just a thought.

Well, time to study for my AP Bio test tomorrow as well. Have a nice day!

The Digestive System Lab

Digestive Organ Model

Digestive Organ	Material Used	Approximate Length (cm)
Mouth	red ribbon	12.2
Esophagus	gold ribbon	39.5
Stomach	purple ribbon	14.6
Small Intestine	white string	731.52
Large Intestine	blue ribbon	182.88
TOTALS	-	990.70 => 9.9070m

Questions
1. We took approximate measurements of our own digestive systems and used lengths of string or ribbons to create a crude model representing its length. It was interesting to see how much longer the small intestine was, even longer than all of the other sections put together. I would assume that that length makes the food take longer to pass through the small intestine, and thus allows more nutrients and material to be absorbed from the food.

2. height = 6' 0" = 72 in. = 1.8288 m.
ratio of height to length of digestive system- approximately 1 : 5.4
Since my digestive system is about five and a half times longer than my height, I can only assume it has been folded, squeezed, and stuffed to stay inside my belly.

3. I would think that food particles would take possibly a day or two- from 24 to 48 hours- from the moment they are swallowed to the time when they are finally excreted, varying based on posture and level of activity. However, I am surprised to learn that it actually takes, on average, "53 hours total transit time, from eating to elimination in stool" (Picco). I think that the horrendously long time that our digestive system takes to work is for completely sanitizing and breaking down swallowed food, absorbing as much of the nutrients as possible, and then packaging it (ewww) so that it can be removed efficiently.

4. Digestion is the breakdown of ingested foods and material into forms that the body is then able to manipulate and absorb nutrients from. Digestion involves the mouth (saliva), stomach (digestive enzymes), small intestine, and large intestine, while absorption occurs only in the small and large intestines.

5. How do stomach enzymes and acids break down the many different kinds of food we eat?
Are we born with DNA coding that is specific for each food / molecular substance?

SMART Goals

Specific, Measurable, Attainable, Relevant, Time-bound Goals

I will work towards managing my time to attain a nine hour sleeping time for an entire week (10pm bedtime), pushing through homework, sports practices, and planning out studying times. I plan to use the google calendar app to completely plan out my week, and also giving me more experience in learning how quickly I work for specific subjects and assignments, making future estimations more accurate.

I will also create a studying plan that works the most efficiently for myself, through experimenting with different formats and mediums: electronic, paper on a clipboard, outline style, diagram based, chicken scratch notes, etc. This will be implemented throughout the semester and be measured through test and temp-check scores.