Other ventilatory responses

Question 1

protective reflexes

Answer 1

protect respiratory system from irritant materials and noxious agents

Question 2

examples of protective reflexes

Answer 2

cough, sneeze, immediate cessation of breathing

Question 3

where do receptors originate?

Answer 3

between airway epithelial cells
sneeze receptors - nose or pharynx
cough receptors - larynx, trachea, bronchi

Question 4

initiation of cough reflex

Answer 4

medullary respiratory neurons cause a deep inspiration and a violent expiration - particles and secretions are moved from smaller to larger airways and aspiration of materials into the lungs is prevented

Question 5

inhibition of cough reflex

Answer 5

alcohol - susceptibility to choking and pneumonia

Question 6

voluntary control of breathing

Answer 6

descending pathways from cerebral cortex to motor neurons of respiratory muscles

Question 7

when can’t voluntary breathing be maintained?

Answer 7

involuntary stimuli, e.g. increased co2 or [H+], become intense.
e.g inability to hold breath for long

Question 8

deliberate hyperventilation

Answer 8

lowers alveolar and arterial co2 and increases o2
low co2 may still permit breathholding at a time where exertion is decreasing the arterial o2 levels, causing unconsciousness or drowning

Question 9

J receptors

Answer 9

sensory receptors in the lungs - capillary walls or interstitium.
normally dormant, but stimulated by an increase in lung interstitial pressure, e.g. collection of fluid.

Question 10

when does lung interstitial pressure increase?

Answer 10

vascular congestion caused by:
occlusion of a pulmonary vessel (pulmonary embolism)
left ventricular heart failure
strenuous exercise

Question 11

main reflex effects

Answer 11

rapid breathing (tachypnea)
dry cough
sensations of pressure in the chest
dyspnea - feeling that breathing is labored or difficult