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CVPR: Pulmonary > Control of Respiration > Flashcards

Flashcards in Control of Respiration Deck (7)
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Inputs into the medulla

-peripheral chemoreceptors: located @ carotid bodies
-central chemorecptors: located on ventral surface of medulla


Respiratory center of brain



Types of peripheral chemoreceptors

1. increases ventilation in response to low arterial O2
2. increases ventilation in response to high arterial PCO2 ==> fast, seconds
3. increases ventilation in response to high arterial [H+] ==> fast, only mediator of response to metabolic acid-base insults


Properties of central chemoreceptors

-located @ medulla
-bind protons in CSF, but sense arterial CO2
-response is slow (minutes)
-mediates 80% of ventialtory response to high PaCO2 under long-term conditions


Integrated response to high altitude (short-term)

-decrease PIO2 ==> decrease PaO2 ==> increased activation of peripheral O2 receptors ==> increased ventilation ==> increased PaO2
-increased Va ==> decreased PaCO2 ==> decreased activation of central proton receptors ==> some suppression of increased Va ==> initial recovery of PaO2 is incomplete
-compensation occurs over 2-3 days ==> normal PaO2


Acclimatization to high altitude

-decreased PaCO2 ==> increased pH/alkalosis = respiratory alkalosis
-compensation: decreased bicarb reabsorption ==> decreased in pH ==> more H+ ==> increased central H+ receptor activation/removal of suppression of ventilation


Increased ventilation during exercise

-initially stimulated by increased CO2 consumption
-as Vo2 consumption increases, protons also contribute to increased stimulation