lecture 12 - control of breathing Flashcards
What are the 3 basic components of the control of breathing system?
Central control (brainstem), central/peripheral sensors, effectors (respiratory muscles)
What sensors are used to feedback to the brainstem for control of breathing?
Chemoreceptors, lung stretch receptors
Where is the respiratory centre in the CNS?
The brain stem (pons & medulla)
What nerves are the major output of the central respiratory centre?
Phrenic nerves
Where are the central chemoreceptors for the respiratory system located?
The medulla
What are the central chemoreceptors in the respiratory centre of the medulla sensitive to?
PCO2, but not PO2 of blood
How do the central chemoreceptors in the respiratory centre of the medulla detect changes in PCO2?
They respond to changes in pH in the ECF when CO2 diffuses out of the cerebral capillaries
Where are the peripheral chemoreceptors of the respiratory system found?
In the carotid and aortic bodies
What do the carotid and aortic bodies detect?
changes in PO2, PCO2, H+
Which chemoreceptors are involved in the ventilatory response to hypoxia?
The peripheral chemoreceptors (carotid and aortic bodies) as they are the only receptors that detect PO2 as well as PCO2
What can be the long term result of chronic hypoventilation?
CO2 retention (long-term hypercapnia) which leads to resetting of chemoreceptors and then hypoxia is the main trigger for ventilation (which is dangerous because O2 has to get quite low to trigger compensatory mechanisms)
Which receptors in the lungs aid in the control of breathing?
Stretch receptors
