Which of the following statements is true regarding the normal mechanism of ventilation?
A) There must be a continuous column of air from the pharynx to the alveoli.
B) The lungs must lie within a sealed-off thoracic cavity.
C) The inner and outer pleural membranes must be separated by a thin film of fluid.
D) The diaphragm, when contracted, will be lowered.
E) All of the answer choices are true.

Question

Quizplus · Accepted Answer

All of the answer choices are true. A continuous column of air is necessary to maintain pressure gradients for air to flow, the lungs are enclosed in the thoracic cavity to allow for negative pressure breathing, the pleural membranes need to be separated to prevent friction during breathing, and the contraction of the diaphragm causes it to lower, increasing the volume of the thoracic cavity and facilitating inhalation.

Which of the Following Statements Is True Regarding the Normal