9: Physiology IV Flashcards
What is Henry’s Law?
The amount of gas which dissolves in blood is directly proportional to the partial pressure of that gas
Is dissolved oxygen the only means of oxygen transport to tissues?
No
Most oxygen is transported in the blood while bound to ___.
haemoglobin
In which two forms is oxygen found in the blood?
Dissolved
Bound to haemoglobin
How many oxygens can each haemoglobin molecule bind?
Why?
4
4 haem subunits
What is the equation for calculating oxygen content of arterial blood (CaO2)?
CaO2 = 1.34 x [Hb] x SaO2
What is the equation for calculating the oxygen delivery index?
DO2I = CaO2 x CI
What can impair oxygen delivery to tissues?
Decreased PaO2
Respiratory disease
Anaemia
Heart failure
Binding of one oxygen molecule to haemoglobin increases haemoglobin’s affinity for oxygen. What is this called?
What shape does this produce on a graph?
Cooperativity
Sigmoid curve
Which mnemonic is used to remember all this oxygen-haemoglobin shizzle?
CADET face RIGHT
What causes the oxygen-haemoglobin dissociation curve to shift to the right?
CADET FACE RIGHT:
Inc. carbon dioxide
Decreased pH
Inc. 2,3-DPG
Exercise
Inc. temperature
What causes the oxygen-haemoglobin dissociation curve to shift to the left?
Dec. carbon dioxide
Inc. pH
Dec. 2,3-DPG
Dec. temperature
What is the other type of haemoglobin found in developing foetuses?
Foetal haemoglobin
Foetal haemoglobin has a (higher / lower) affinity for oxygen than adult haemoglobin.
higher
Where is foetal haemoglobin compared to adult haemoglobin on an oxygen-Hb dissociation curve?
Shifted to the LEFT
higher affinity
