igor999
Forum Senior
Topics: 56
Posts: 83
|
Sickle Cell Anemia cause the oxygen carying capacity to be which of the following?
A) 33%
B) 61%
C) 75%
D) 78%
I know sickle cell anemia decreases oxygen carrying capacity, so would the answer be 33%?
thanks
|
| P4a99
Forum Fanatic
Topics: 35
Posts: 2,212
|
1) red cell 2,3-BPG concentration is increaed in anemia and in a veriety of diseases in which there chronic hypoxia.
2) sorry, what do you mean exactly by the carrying capacity? is that the same as Hb saturation? if it is, then:
in normal states oxygenated blood leaving the lungs is almost 93-100% saturated and reduced blood returning from the tissues is from 19-73% saturated.
So i think the answer would be C or D ( common they are too close! ) not the others.
Note: i may be screwing up ... big guys please give us a hand over here.
___________________
2008 Step 1 Study Plan Discussion ........ My Blog
|
| new_n_lost
Politically InCorrect
Topics: 650
Posts: 6,058
|
Sickling Occurs when the percentage of the of the Sickled RBCs in PB is more than 60%. So if u ask me wht happens to O2 carrying Capacity then i wud say Dec to 60%.
Where is this question from plz mention the source if u dont have an answer provided with question cos then its necesssary to ascertain the area which the question might refer to.
___________________
FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
|
| P4a99
Forum Fanatic
Topics: 35
Posts: 2,212
|
NNL please why 60% precisely?
___________________
2008 Step 1 Study Plan Discussion ........ My Blog
|
| new_n_lost
Politically InCorrect
Topics: 650
Posts: 6,058
|
Well for the Vaso Occlusion crisis to occur the HbS concertration has to be more than 60%. Now the HbS molecule has ability to bind O2 but at a lesser percentage than the Normal. The cells with Sickle cells r there and also the cells which have the HbS in them but havent sickled yet. Slight Deoxygenation causes the Cells to change their shape and the O2 carrying Capacity dec bcos of the Polymerization of the HbS molecules. Once the Polymerization occurs the Affinity for Oxygen dec and therefore u have the Crisis. Now as u know that Site 3 on the Hb molecule has 75% of it bound to O2 and that is normal occuring event. And Site 2 has somewhere around the 50% mark (P50). Now if Anything were to decrease the O2 content of the Blood Site 3 is gonna give its O2 and Site 2 is reluctant to give up it O2 molecule. SO for (in My opinion) Sickling to Occur Site 3 has Given up O2 and Site 2 is left and as the O2 tension dec the Polymerization of the HbS molecule Occurs but it still doesnt Gives up its O2 molecule. So as soon as the Hb Molecules go below Deoxygenation mark below than normal the cells predisposed to Sickling Start Sickling this starts a Sickling Effect along the Blood vessels and any RBC which is either Previously Sickled gets more polymerized and Sickling Start to occur.
I hope i have made sense to u all. but this is my opinion i maybe wrong but this is wht i know.
___________________
FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
|
| perfectcube
Forum Newbie
Topics: 1
Posts: 13
|
The carrying capacity depends on the severity of the anemia which of course varries between different patients. Therefore the question is stupid...
HBS has indeed lower affinity for oxygen due to the increased level of 2,3-DPG and the amount of HbS that is polymerized, but this does not affect the carrying capacity.
I recommend to whoever is interested to read about the possible therapeutic effect of NO in SCA which acts by increasing the affinity of HbS for oxygen and therefore decreasing its polymerisation and consequent sickling.
Did I mention that the question is stupid?
|
| new_n_lost
Politically InCorrect
Topics: 650
Posts: 6,058
|
No Buddy Carrying Capacity Does Depend on the Severity of Anemia. How can u say tht if that was true then Y in Anemia we have Normal SO2 and PaO2.
THe Carrying Capacity of Hemoglobin is entirely dependent on the Structure of Hemoglobin molecule. such as Methhemoglobinemia and CO poisoning.
How R u guys corelating 2,3 BPG to this Process.
___________________
FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
|
| new_n_lost
Politically InCorrect
Topics: 650
Posts: 6,058
|
Praying Did u get my explanation ???
___________________
FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
|
| hope4dabest
Forum Elite
Topics: 16
Posts: 433
|
all i know is that site 1 and 2 og Hb doesnt leave oxygen coz of high affinity so has to be more than 50%...dont know exactly
|
|
| |
| | | | | | | | | |
