chapter 6 - gas transport by blood Flashcards
What is Henry’s law?
The amount of dissolved gas is proportional to the partial pressure
How is O2 carried in the blood?
How is CO2 carried in the blood?
dissolved and bound to Hb
- the most is bound to Hb
dissolved, HCO3, carboxyhemoglobin
- the most is as HCO3
Which way dose sickle cell disease shift the Hb-sat curve?
rightward
- deoxygenated sickle Hb is poorly soluble and crystallizes in the cell
Which way does COHb shift the Hb-sat curve?
leftward
CO is 240 times the affinity for Hb
O2 capacity
max amount of O2 that can be combined with Hb
What is the O2 saturation of Hb defined as?
The percentage of available binding sites in Hb that have O2 attached
O2 combined with Hb/O2 capacity x 100
What is the bohr effect?
The rightward shift of the O2 dissociation curve caused by high CO2
High CO2 causes a high H+ concentration which shifts the curve right (favours the T or tense state which is the deoxy form of Hb)
What is the normal P50?
27 mmHg
What is the chloride shift?
Respiratory acidosis causes chloride to shift into Hb from the plasma
- secondary to H+ in the cell from the formation of bicarb. H+ can’t diffuse out of the cell, so Cl- shifts in to keep the cell neutral
What is the Haldane effect?
Oxygenated Hb shifts the CO2 dissociation curve to rightward
- deoxygenated Hb is better at binding CO2 and the H+ ion produced when carbonic acid dissociates
- oxygenated Hb causes release of CO2 from the Hb
What is the Henderson Hasselbalch equation?
pH = pKa + log [[HCO3] / 0.03(PCO2)]
- pKa is 6.1
- ratio of HCO3 to 0.03PaCO2 is 20 at a pH of 7.4
What are the types of hypoxia?
Hypoxic hypoxia
Anemic hypoxia (anemia, CO poisoning)
Circulatory hypoxia
Histotoxic hypoxia (cyanide poisoning)
