Breath of Fresh Air
Which muscle is the primary driver of quiet, resting inspiration
Diaphragm
Approximately what percentage of oxygen in the blood is transported bound to hemoglobin
About 98%
Which brainstem structure is often referred to as the pacemaker of respiration
Pre-Bötzinger complex
Low-pitched, soft breath sounds heard over peripheral lung fields are called
Vesicular breath sounds
Each 1 L/min increase in oxygen via nasal cannula raises FiO₂ by approximately how much
About 4%
During normal exhalation at rest, air leaves the lungs mainly because of
Passive elastic recoil of the lungs
Most carbon dioxide in the bloodstream is transported in what form
As bicarbonate ions
Central chemoreceptors primarily respond to changes in the levels of which substance
Carbon dioxide (via CSF pH)
A patient with airway narrowing is most likely to have which abnormal lung sound
Wheezes
Which ventilator setting helps prevent alveolar collapse at end-expiration
PEEP
What pressure remains sub-atmospheric throughout the entire breathing cycle and helps keep the lungs expanded
Intrapleural pressure
A leftward shift of the oxyhemoglobin dissociation curve indicates
Increased affinity of hemoglobin for oxygen
Which receptor type is stimulated by pulmonary congestion and can trigger rapid, shallow breathing
J (juxtacapillary) receptors
Increased tactile fremitus most strongly suggests
Lung consolidation
Which disease is the most common infectious cause of death worldwide and primarily affects the lungs
Tuberculosis
When the thoracic cavity expands during inspiration, what happens to intrapulmonary pressure
It decreases below atmospheric pressure
Which physiological change would most likely cause a rightward shift of the oxyhemoglobin dissociation curve
Increased temperature or decreased pH
The dorsal respiratory group mainly contributes to which breathing function
Control of inspiration
A PaO₂ value below what level indicates hypoxemia
60 mmHg
A PaO₂/FiO₂ ratio of 250 suggests which type of respiratory support may be needed
Non-invasive oxygen support (e.g., high-flow nasal cannula)
A patient has reduced diaphragmatic movement due to hyperinflated lungs. Which respiratory condition most likely explains this finding
Emphysema
During vigorous exercise, why does oxygen unload more readily from hemoglobin at the tissues
Increased CO₂, temperature, and acidity reduce hemoglobin’s affinity for oxygen
During high-intensity exercise, which respiratory center increases activity to meet ventilatory demand
Ventral respiratory group
Diminished breath sounds, dyspnea with activity, and lower extremity edema most strongly point toward which condition
Congestive heart failure exacerbation
Thick, dehydrated mucus due to faulty chloride ion transport is characteristic of which condition
Cystic fibrosis