Control Of Pulmonary Ventilation Flashcards
Medullary centers
Dorsal resp group: insp and responsible for setting basic resp rhythm
Ventral resp group: insp and active exp
Pontine center
Modulate activity of medullary centers
Without breathing pattern is ataxic
Apneustic center: lower pons, excites inspiration and prolongs inspiration
Pneumotaxic center: pontine resp group, upper pons, inhibit insp, limits size of TV
Higher brain centers
Cerebral cortex
Modulates medullary and pontine
Voluntary control of resp muscles
Pulmonary stretch receptors
Provide information about lung vol to brain
Muscle proprioceptors and joint receptors
In diaphragm and intercostal sense degree of stretch and regulate their contraction
Irritant and juxtacapillary receptors
Irritant: epithelial lining of large and small airways
Respond to hot or cold air and noxious chemicals
Sneezing, coughing, laryngeal spasms, constricts airways, shallow rapid resp pattern
Juxtacapillary: lung parenchyma close to alveolar capillaries
Respond to anesthetic gases, mediators (histamine), engorgement of pulmonary capillaries and interstitial edema
Induces shallow rapid resp pattern
Central chemoreceptors
CO2 most important for regulation in blood
80% but respond slower
Peripheral chemoreceptors
Carotid and aortic bodies 20% but more rapid Carotid via carotid sinus nerve Aortic via vagus nerve Sensitive to CO2, O2, and pH Carotid more sensitive
Hyper panic ventilatory drive
Constant high levels of CO2: Dec PO2, inc O2, and dec hypercapnic drive, such as end stage emphysema
Hypoxia ventilatory drive not as sensitive
Reduced by sleep and increasing age
Ventilatory response to oxygen
Does not activate till 50mmHg
Will also inc sensitivity of hypercapnic
Ventilatory response to pH
Fall in arterial pH will increase rate of ventilation
Eupnea
Normal quiet breathing
Dyspnea
Difficulty in breathing
Hyperpnea
Increased rate and depth of breathing due to increased metabolic needs
No change in acid base status
Tachypnea
Rapid shallow breathing
