5.1 Chemical control of Breathing Flashcards
What is the pCO2 in plasma?
4.2 -6.0 kPa
What is the pO2 in plasma?
9.8 -14.2 kPa
What is the normal concentration of bicarbonate in plasma?
21-29 mmol/L
What is the normal pH range of plasma?
7.35 to 7.46
What is a rise in pCO2 called?
Hypercapnia
What is a fall in pCO2 called?
Hypocapnia
What is a fall in pO2 called?
Hypoxia
What is hyperventilation?
Increased ventilation without a change in metabolism
pO2 will rise
pCO2 will fall
What is hypoventilation?
Decreased ventilation without a change in metabolism
pO2 will fall
pCO2 will rise
What is the carbonic acid-bicarbonate buffer system?
The system that allows the concentration of bicarbonate to control the amount of dissolved CO2 in the blood.
What is the condition called which has a rise in plasma pH due to increased ventilation?
Respiratory alkalosis
What is the condition called which has a fall in plasma pH due to decreased ventilation?
Respiratory acidosis
How is respiratory acidosis compensated for?
Extra release of HCO3- from the kidneys
What is metabolic acidosis?
A fall in pH due to excessive acid production by tissues. The acid reacts with HCO3- and causes the concentration of HCO3- in the plasma to drop, making the blood more acidic.
What is metabolic alkalosis?
The concentration of HCO3- in the blood rises eg. after excessive vomiting. Plasma becomes more alkaline
What do peripheral chemoreceptors detect?
Drops in pO2
What do peripheral chemoreceptors stimulate if there is a fall in pO2?
Increased ventilation
Increased blood flow
Where can peripheral chemoreceptors be found?
Carotid and aortic bodies
Where are central chemoreceptors found?
Medulla
What do central chemoreceptors detect?
Changes in pCO2
pH changes
How is CSF HCO3- concentration controlled?
Choroid plexus cells
What happens to the HCO3- concentration in the CSF if there is a prolonged change in the plasma pH?
The choroid plexus cells will alter how much HCO3- can enter the CSF
