Chemical Control of Breathing Flashcards
What is a rise and fall of pCO2 called?
rise = hypercapnia, fall = hypocapnia
What will happen to pCO2 and pO2, during hyperventilation without a change in metabolism?
pO2 will rise and pCO2 will fall
What causes Hypocapnia?
If pO2 falls alone and is corrected by increased ventilation, pCO2 will fall
What happens if the pH falls below 7?
Enzymes denature
What happens if the pH rises above 7.6?
Free calcium concentration drops causing tetany
What organ compensated for respiratory acidosis and alkalosis and how?
Kidneys change the concentration of hydrogen carbonate via reabsorption, but it can take 2-3 days
What organ compensates for metabolic acidosis?
Lungs via a change in ventialtion
Why is metabolic alkalosis harder to correct?
A decrease in ventilation may also cause hypoxia
Where are the peripheral chemoreceptors and what do they respond to ?
Carotid and aortic arch, respond to large drops in pO2
Where are the central chemoreceptors and what do they respond to ?
Medulla of the brain, respond to small changes in pCO2 of the CSF and ECF
How is hydrogen carbonate concentration controlled in the CSF?
Choroid plexus cells (NOT the kidney)
Name 2 cell types involved in the blood brain barrier
Astrocyte and Pericyte
What happens in the brain when there is a prolonged change in pCO2?
The CSF Hydrogen carbonate concentration can change to “set” the system to the new pCO2
