Control of respiration 2 Flashcards
Below what pH does blood become fatal?
7
Above what pH does blood become fatal?
7.70
What causes CO2 retention?
Hypoventilation
What does CO2 retention cause?
Increase in PCO2, H+ and HCO3- causing respiratory acidosis
What happens when H+ and HCO3- levels are high?
Severe asthma and pneumonia
What happens if HCO3- levels are low?
Increased H+ causing elevated fat/protein catabolism
How can HCO3- be increased?
Hyperventilation
When does respiratory alkalosis occur?
CO2 loss decreasing PCO2, H+ and HCO3- levels
How can CO2 loss be compensated?
Reduced renal excretion of H+ and HCO3-
How can metabolic alkalosis be avoided?
Hypoventilation
When does metabolic alkalosis occur?
Ingestion of HCO3- or loss of H+
What does exercise cause in gas levels?
PO2 increase and decrease in PCO2 with no change in H+
How is respiration stimulated during exercise?
Neurogenic mechanisms
What are the immediate effects of increased ventilation during exercise?
Neurogenic, anticipation and rising temperature in skeletal muscles
What are the later effects of increased ventilation during exercise?
Generation of CO2, falling blood pH and lactic acid in muscles
What happens when PO2 levels are low?
Hypoxia
What is hypoxic hypoxia?
PO2 of arterial blood is reduced causing pressurisation and gaseous suffocation
What is anaemic hypoxia?
Carrying capacity is reduced due to low Hb causing blood cell diseases
What is ischaemic hypoxia?
PO2 and Hb are normal but blood flow to tissues is compromised
What is histotoxic hypoxia?
Cells can’t use supplied oxygen causing cellular poisoning
