Respiratory: Gas Transport Flashcards
What is Henry’s Law?
The amount of a given gas dissolved in a liquid is propotional to the partial pressure of the gas in equilibrium with the liquid
So- increase the partial pressure of the gas, increased gas will dissolve in the liquid
How is oxygen transported in the blood
bound to haemoglobin
dissolved
How many haem groups does haemoglobin contain
four
Describe the co operivity displayed by haemoglobin
When oxygen binds to one haem group it increases the affinity for the other haem groups for oxygen
What is the primary factor in determining the percentage od saturation of haemoglobin
PO2
What is the significance of the sigmoid shape of the O2-Hb dissociation curve
In pulmonary capillaires- a change in PO2 does not really affect the Hb saturation
In systemic capillaries- a small change in PO2 will result in oxygen dissociating from Hb
What is the oxygen delivery index
Oxygen content of arterial blood times the cardiac index
What determines the oxygen content of arterial blood
Hb conc
Saturation of Hb with oxygen
What can impair oxygen delivery to the tissues?
Respiratory disease
Heart failure
Anaemia
What does the Bohr effect mean
That there is an increased release of oxygen in the following conditions at tissues: Increase carbon dioxide Decreased pH Increased temp Increased 2,3 biphosphoglycerate
Where is myoglobin present
skeletal and cardiac muscle
How many haem groups are in a myoglobin molecule
one
What is the dissociation curve shape in myoglobin
hyperbolic
When does myoglobin release o2
in very low oxygen conc
Why is this useful
Provides oxygen in anaerobic conditions
What does the presence of myoglobin in the blood indicate
muscle damage
How is carbondioxide transported in the blood
as a solution
as bicarbonate (most)
as carboamino compounds
Where does bocarbonate formation occur and what enxyme catalyses it
red blood cells
carbonic anhydrase
When are carboamino compounds formed?
By combination of CO2 with terminal amine groups in blood proteins such as globin of haemoglobin
What is the haldane effect
removing oxygen from Hb increases its affinity for CO2 and H plus
How do the bohr and haldane effect work together
this ensure release of O2 at tissues is coupled with uptake of CO2 to be removed
