Anatomy B/C

[SciBomb97]

I was reading stuff about the oxygen-hemoglobin dissociation curve, and the wording is on a slightly higher level than I can understand.
Can anybody explain it in plain English?

The curve is a graphic representation of the factors that affect O2's affinity for hemoglobin.
The most important factor that determines the percent O2 saturation of hemoglobin is partial pressure of O2 (PO2). If you look at the dissociation curve, the partial pressure of O2 is on the x axis and % saturation is on the y axis.
This is the key relationship: When PO2 is high, hemoglobin has more affinity for O2. When PO2 is lower, there is less affinity for O2.

You may have seen examples of when the curves are shifting as well.
This illustrates the other factors that affect hemoglobin affinity for oxygen.
One such example is the Bohr effect (or Bohr shift). An increase in H+ causes O2 to unload from hemoglobin. So at lower blood pH (more H+), the curve butterfly to the right (or downward), demonstrating a lesser affinity. At higher pH, the curve shifts left (or upward), demonstrating the converse.
Here is a picture ref: http://chemistry.ewu.edu/jcorkill/biochem/fig_07_11.jpg
Another factor is temperature. As temperature increases, the amount of O2 released from hemoglobin increases too.
There's also a substance called BPG and is formed in red blood cells. The more BPG there is, the more O2 is unloaded from hemoglobin (having the same effect as an increase in temperature)
Hope that helped a bit!

Thanks

[rkoopma2]

I have a question that recently came up that left me debating with my partner:
Where does fat digestion begin?
I have read many textbooks that say the mouth produces lingual lipase, which would imply that fat digestion begins in the mouth.
However, in class we were taught that fats are digested in the small intestine via pancreatic lipase, and this seems to be the correct answer among many online multiple choice tests I've taken. However I still would think that the answer should be the mouth because of lingual lipase.

Any thoughts on this?

Yeah, salivary lipase (or lingual lipase) starts the digestion of lipids. I believe most of the digestion of lipids, however, occurs in the small intestine.

Accoring to textbook I'm reading, lingual lipase is an enzyme in saliva, but it is not activated until it reaches the acidic environment of the stomach.

[SciBomb97]

Does the book actually say that lipase isn't activated in the saliva or that the optimum activation is in the stomach? Because mine says that the fat amalsification by lipase continues into the stomach.

[foreverphysics]

Does the book actually say that lipase isn't activated in the saliva or that the optimum activation is in the stomach? Because mine says that the fat amalsification by lipase continues into the stomach.

It probably starts in the mouth by saliva but continues into the stomach. What page is this on? You have the blue book, I'm assuming, and my purple book has a kind of pattern in relation to your blue book. Oh, forget that, just, what page is that on?

[SciBomb97]

Trust me, your book is nothing like the one I have.
In fact, I have two!!!

[foreverphysics]

Trust me, your book is nothing like the one I have.
In fact, I have two!!!

I have three. What's the page number?

[TheGenius]

Trust me, your book is nothing like the one I have.
In fact, I have two!!!

Your "book" wouldn't happen to be Wikipedia, would it?

[Kokonilly]

Trust me, your book is nothing like the one I have.
In fact, I have two!!!

I have three. What's the page number?

I have five or six. Working through them one at a time.

To make this useful, how much should we know about diseases not listed in the rules? In years past, I've tended to focus on the rules packet's diseases, but I figure it's good to know at least a little bit about the other basic diseases of each system.

[mnstrviola]

To make this useful, how much should we know about diseases not listed in the rules? In years past, I've tended to focus on the rules packet's diseases, but I figure it's good to know at least a little bit about the other basic diseases of each system.

I have never encountered questions about diseases outside of the rules. However, for the digestive system, you could probably know about stuff like heartburn and diarrhea because they are common symptoms for larger problems/diseases.

[SciBomb97]

Trust me, your book is nothing like the one I have.
In fact, I have two!!!

Your "book" wouldn't happen to be Wikipedia, would it?

By book is absolutely not Wikipedia, although I do sometimes use Wikipedia as a resource on stuff.

Trust me, your book is nothing like the one I have.
In fact, I have two!!!

I have three. What's the page number?

Since the books you have probably aren't the ones I have, you should probably go to the table of contents, find the digestive system section, and then look under the oral cavity section or anything about chemical digestion. Try the secition about saliva or the salivay glands.