End effect of an increase in tissue metabolism on interstitial pCO2
as pO2 rises so does the saturation of Hb
amount of oxygen 1g of Hb can combine with?
amount of O2 (ml) in 100ml of blood
under normal conditions how much oxygen is delivered to the tissues per 100 ml of blood?
5ml, can increase to 15ml during heavy exercise
What factors cause muscle pO2 to stay constantly at 40mmHg during exercise
increase in cardiac output
decrease in affinity for Hb, raise in temp CO2, 2.3DPG and decrease in pH
percentage of blood that gives up its oxygen as it passes through the capillaries
as oxygen is delivered to the tissue Hb releases more oxygen into the blood
chronic hypoxic condition increase what?
2,3, DPG (poor tissue blood flow)
What is the main limiting factor what blood pO2 is greater then one for tissue metabolism?
effects of oxygen poisoning?
brain convolutions and death
What binds to the same site on Hb and oxygen but with a high affinity?
CO, partial pressure of 0.4 will allow CO to equally compete with O2 for binding to Hb. 0.6 is lethal
In CO poisoning what is the affect on blood pO2?
normal, no obvious signs of hypoxia
since pO2 is not depressed there is no low O2 feedback mechanism to increase respiration
can treat with pure oxygen and CO2 in the blood to increase breathing
amount of CO2 transported from the tissues to the lungs in the blood per 100ml blood
CO2 is higher in the venous blood causing an increase in production of H2CO3, this then dissociates and the H is buffered by Hb and the bicarb is exchanged for Cl. The chloride content of venous blood is less then arterial blood
Water moves into the cell to maintain the osmotic equilibrium and causes the cell to swell.
carbonic anhydrase inhibitor, can cause tissue pCO2 to reach 80
what is carbaminohemaglobin?
CO2 bound to the terminal amine group of Hb
pKa is around 7 so 50% is available at blood pH
volume percent change for CO2
52in venous blood to 48 in arterial, 4ml/100ml blood
What is the Haldane effect?
the binding of oxygen to Hb displaces CO2 from the blood in the lungs
The combination of oxygen with Hb causes Hb to become a stronger acid
The more acidic Hb has less affinity for CO2 at the terminal amine group
The increased acidity of Hb causes it to release more H that in turn bind with bicarb and form water and CO2, the CO2 is released from the lungs
This effect doubles the amount of CO2 released from the blood in the lungs and double the amount picked up in the tissues. from 2ml to 4ml.
Normal pH of arterial and venous blood?
7.41 and 7.37
Respiratory exchange ratio?
volume percent of CO2 over the volume percent of O2
Usually in the range of 82 %
using mainly carbohydrates for metabolism increases