Respiratory 31 Flashcards
Where are central chemoreceptors located?
Close to the ventral surface of the medulla
What do the central chemoreceptors fire in response to?
Changes in PCO2?
What are the three regions of chemoreceptors in the medulla?
- Rostral
- Intermediate
- Caudal
What is Hypercapnia?
An increase in the partial pressure of carbon dioxide
What are other central chemosensitive sites?
- Medullary raphe
* Hypothalamus
What parts of the brain mediate Hypercapnis?
The dorsal and ventral respiratory group
What does carbon dioxide do after diffusing from the capillaries to the extracellular space in the brain?
It will interact with water to produce hydrogen ions
What is the excitatory factor for the central chemoreceptors?
The increase in hydrogen ions seen with an increase in CO2
What is the response of central chemoreceptors sensing a low pH?
It will increase firing which activates the respiratory muscles to increase ventilation
Which receptors are responsible for 70% of the response to hypercapnia?
Central chemoreceptors
When does Metabolic Acidosis occur?
When there is the production of acids in the blood not associated with changes in PCO2
What is an example of Metabolic Acidosis?
Lactic acid accumulation during strenuous exercise
What does lactic acid accumulation during strenuous exercise cause?
Peripheral chemoreceptors to sense this and cause hyperventilation
What activates central chemoreceptors?
An increase in arterial PCO2 that produces hydrogen ions
What activates peripheral chemoreceptors?
- Decrease in arterial PO2
- Production of non-CO2 acids which increase pH
- Arterial PCO2 which increases pH
