Transport Of Oxygen And Carbon Dioxide In The Blood Flashcards
How much dissolved oxygen can be delivered in a normal person
15 mL/min
What is the normal oxygen saturation in arterial blood vs venous blood vs muscle/tissues
Arterial = Around 97.5%
- usually just say 100%
Venous = around 40%
Muscles = around 40%
Where does the number 19.88 mL O2 (normal amount of oxygen in arterial blood) come from?
Oxygen physically dissolved x the normal saturation of oxygen bound to hemoglobin
(0.3 mL/100mL) + (19.58/100mL) = 19.88mL
What is the normal oxygen carrying capacity for hemoglobin?
15 g / 100mL
- anything lower is anemia
How much oxygen is distributed to the tissues in a normal person every 100 mL of blood that passes by
20 mL/100mL
What does carbon monoxide and anemia affect?
The amount of valuable hemoglobin
- it does NOT effect the percent saturation or arterial partial pressure of oxygen, only affects that amount of free hemoglobin*
- Oxygen content will decrease by hemoglobin saturation will NOT change*
What shifts the hemoglobin-sat curve left and right (BOHR effects)
Left: increases oxygen affinity/ P50 for oxygen goes down
- low temps
- pH goes up (basic hemoglobin wants to bind oxygen over H+ ions)
- PCO2 goes down
- decreases in 2,3 DPG/BPG content
- presence of HbF
- presence of Carbon monoxide
Right: lows oxygen affinity/ P50 for oxygen goes up
- high temps
- pH goes down (acidic, hemoglobin wants to bind H+ ions over oxygen)
- PCO2 goes up
- increased 2,3 DPG/BPG content
- note that 2,3 DPG does NOT bind to fetal hemoglobin*
2,3 DPG definition
Byproduct of anaerobic respiration in cells
- increased 2,3 DPG causes oxygen to be released easily in oxygen starved tissues
Why is the left shift in carbon monoxide poisoning so bad for tissues and hypoxia?
Because it binds to hemoglobin;o in too hard, preventing unloading of oxygen from other binding sites
- this actually makes oxygen EASIER to bind, which means oxygen actually prefers staying on the hemoglobin and not go to the tissues
What is the most common transport form of carbon dioxide in the body?
Bicarbonate ions
BAND 3 transporter
Protein that contains carbonic anhydrase enzymes.
- essential for generating CO2 -> bicarbonate ions and vise versa
Why is CO2 content higher in venous blood?
Erythrocyte Carbonic anhydrase works more actively in venous blood, causing increased CO2 content and lower pH
What is any molecule that binds a H+ to prevent pH dramatic changes?
A buffer
- note the most common are bicarbonate ions and hemoglobin
Haldane effect
Blood that needs to carry oxygen, will not carry CO2
- also can be said that for any PCO2, the less oxygenate blood will have a higher CO2 content
