Control of Ventilation

Question 1

Ventilatory Control resides within ill defined respiratory centres called

Answer 1

pons and medulla

Question 2

Respiratory centres have their rhythm modulated by

Answer 2

emotion

voluntary over-ride

mechano-sensory input from the thorax

chemical composition of the blood detected by chemoreceptors

Question 3

Phrenic nerve in ventilation controls the

Answer 3

diaphragm

Question 4

Intercostal nerve in ventilation controls

Answer 4

external intercostal muscles

Question 5

Central chemoreceptors are the primary ventilatory drive and are found in the

Answer 5

medulla

Question 6

central chemoreceptors respond directly to

Answer 6

H+ (directly reflects PCO2)

Question 7

peripheral chemoreceptors are the secondary ventilatory drive and are found in

Answer 7

carotid and aortic bodies

Question 8

peripheral chemoreceptors respond directly to

Answer 8

plasma H+ and PO2 (not so much PCO2)

Question 9

central chemoreceptors in the medulla detect changed in the….

Answer 9

CSF surrounding the brain

Question 10

Ventilation is reflexly inhibited by a decrease in arterial

Answer 10

PCO2 (reduced CSF H+)

Question 11

Changes in plasma pH alter ventilation via the

Answer 11

peripheral chemoreceptor pathways

Question 12

If plasma pH falls (H+ increases), ventilation will be

Answer 12

simulation (acidosis)

Question 13

If plasma pH increases (H+ falls) ventilation will be

Answer 13

inhibited (vomiting occurs due to alkalosis)

Question 14

Voluntary breathing is controlled by

Answer 14

descending neural pathways from cerebral cortex to respiratory motor neurons

Question 15

barbiturates and opioids …….. the respiratory centre

Answer 15

depress

overdose often results in death as a result of respiratory failure

Question 16

Nitrus Oxide blunts peripheral chemoreceptor response to

Answer 16

falling PaO2

(safe normally but not in chronic lung disease patients where they have a ‘hypoxic drive’. These will aggravate the situation)