Part VI Flashcards
A decreased V/P ratio results in what?
increase in physiologic shunt blood
What is physiologic shunt blood?
blood that doesn’t pick up oxygen when it goes through the lungs
An increased V/P ratio results in what?
increase in physiologic dead space
What is physiologic dead space?
area in the lungs where oxygenation is not taking place
What is VO2 max?
the max oxygen that can be absorbed from the lung and delivered to the tissue per minute
What is the best measure of cardiovascular fitness?
VO2 max
VO2 max is limited by what?
cardiac output, not pulmonary ventilation
During exercise, what improves as stroke volume increases?
VO2 max
Does heart rate stay constant as stroke volume increases?
yes
What are the VO2 maxes for cardiac patients, sedentary person, endurance athlete?
- 5 L/min
- 0 L/min
- 0 L/min
How much oxygen is carried from the lung to the tissue?
5mL/dL
How much oxygen is dissolved into the tissue
3%
How much oxygen is bound to hemoglobin?
97%
How much carbon dioxide goes from tissue to lungs?
4mL/dL
How much carbon dioxide is dissolved?
7%
How much carbon dioxide is bound to hemoglobin?
23%
How much carbon dioxide is made into bicarbonate acid?
70%
How much carbon dioxide can be used to make metabolic water?
1mL/dL
What is the pH of arterial blood?
7.41
What is the pH of venous blood?
7.37
What makes venous blood more acidic?
bicarbonate, phosphate and protein buffers
In exercise, venous blood can drop to what pH?
6.9
When oxygen is in the cells, How much is turned into CO2 and how much of it is converted to water?
80% CO2
20% water
What is utilized for energy that increases the metabolic water up to 30%?
fatty acids
If only ___ are used for energy, then no metabolic water is generated from oxygen. What is it converted to?
CHO, CO2
70% of carbon dioxide is carried in the form of what?
bicarbonate ion
What catalyzes the reaction of water and CO2 in RBCs?
carbonic anhydrase
As HCO3 leaves the RBC, it is replaced by what?
Cl-
What does the RBC do when carbon dioxide is bound to hemoglobin?
it reacts with amine radicals of hemoglobin and other plasma proteins
How much CO2 is dissolved ?
7%
As PO2 decreases, hemoglobin does what?
releases more oxygen
If PO2 is at 95mmHg in the arteries, what kind of saturation does hemoglobin have?
97%
If PO2 is at 40 mmHg in the veins, what kind of saturation does hemoglobin have?
70%
A shift to the right in the oxy-hemoglobin curve promotes what? Why?
dissociation because there is an increase in temperature, CO2, decrase in pH and increase in 2,3 diphosphoglycerate (2,3 DPG)
Where is a shift to the right on the oxy-hemoglobin curve promoted?
tissues
A shift to the left in the oxy-hemoglobin curve promotes what and where?
association, promoted in lungs
What does carbon monoxide do?
competes with oxygen for binding sites on hemoglobin
What affinity does carbon momoxide have for hemoglobin?
250x that of oxygen
small partial pressures of carbon monoxide will saturate how much hemoglobin, and can decrease oxygen carrying cappacity of hemoglobin by how much?
97% of the hemoglobin, decreases oxygen carrying capacity by 50%
How much CO can be lethal?
1%
How is CO poisoning treated?
95% oxygen and 5% CO2 to rapidly displace CO
What happens when you treat CO poisoning?
there is an increase in ventilation because of more CO2
A small amount of what is produced by the body?
CO
What is the function of carbon monoxide in the body?
signaling molecule in nervous system, vasodilator, important role in immune, respiratory, GI, kidney and liver systems
