Control Of Breathing

Question 0

Pons respiratory center

Answer 0

Apneustic center- goes to drg and leads to inspiration

Pneumotaxic center- goes to apn center decreases tidal volume and thus increases resp rate.

Question 1

Dorsal and ventral respiratory groups of the medullary respiratory center

Answer 1

Drg- involved in inhalation

Vrg- increase resp rate and causes active respiration

Question 2

Ventilation regulation

Answer 2

CO2 is the most important regulator of ventilation

Vent inc by high PaCO2, low PaO2 and low pH

Rate and depth of tidal volume are controlled to maintain a PaCO2 at around 40 mmHg

Question 3

Central chemo rec

Answer 3

Respond to changes in pH in CSF but not blood
Direct stimulation is from decreas in pH
Indirect stimuli is from PaCO2
O2 and CO2 are freely permeable to blood brain barrier

Question 4

Peripheral chemoreceptors

Answer 4

Found in the carotid sinus and carotid body

Sensitive to changes in PaO2 (most important), PaCO2, and [H].
Ventilation is stimulated by decreased O2, increased H, and CO2
Pa02 below 60 causes increased vent.

Question 5

Hering-Breuer reflexes

Answer 5

Inflation-stimulated by increases I lung volume, results in cessation of inspiration

Deflation-stim by abrupt lung deflation, causes initiation of inspiration

Question 6

J-receptors

Answer 6

Found in walls of pulm micro vessels, stimulated by pulm emboli,interstitial edema.
Causes rapid shallow breathing and may be responsible for shortness of breath.