Respiratory System Anatomy & Physiology Flashcards

The pores of Kohn connect adjacent alveoli and serve which function?

Answer: Allowing collateral ventilation to prevent atelectasis

Pores of Kohn are inter-alveolar openings that enable collateral ventilation, allowing air to bypass obstructed airways and help prevent or resolve atelectasis.

Which parameter best describes the ease with which the lung-chest wall system can be inflated?

Answer: Compliance

Compliance (ΔV/ΔP) measures the volume change per unit of pressure change; higher compliance means the respiratory system inflates more easily for a given pressure.

Mucociliary clearance is most effective at which ciliary beat frequency, and which condition most severely impairs it?

Answer: 10–15 Hz; cigarette smoking

Airway cilia beat optimally at 10–15 Hz, and cigarette smoke is the most potent inhibitor of mucociliary clearance, causing ciliary paralysis and mucus hypersecretion.

During a forced vital capacity (FVC) maneuver, the FEF 25–75% represents:

Answer: Flow over the middle 50% of the FVC, reflecting small airway function

FEF 25–75% (mid-expiratory flow rate) measures average flow between 25% and 75% of the FVC and is a sensitive indicator of early small airway obstruction.

The blood supply to the bronchi and conducting airways (as opposed to the alveolar tissue) is provided by the:

Answer: Bronchial arteries arising from the aorta

Bronchial arteries branch directly from the thoracic aorta and supply oxygenated blood to the walls of the bronchi and bronchioles down to the level of the respiratory bronchioles.

Laplace's law applied to the alveolus states that the pressure inside a sphere is proportional to:

Answer: 2 × surface tension / radius

Laplace's law: P = 2T/r; smaller alveoli generate higher recoil pressures, which is why surfactant is critical—it reduces T disproportionately in smaller alveoli to prevent collapse.

The primary central respiratory rhythm generator is located in which brainstem region?

Answer: Pre-Bötzinger complex in the medulla

The pre-Bötzinger complex, a bilateral cluster of neurons in the ventrolateral medulla, is the essential pacemaker that generates the basic rhythmic pattern of breathing.