What is the function of the very small amount of pleural fluid that is found in the pleural space?
a. Composes part of anatomic shunt.
b. Liquid barrier for pathogens.
c. Part of pulmonary blood flow.
d. Reduces friction.
Q. 2 To what structures do the parietal pleural membranes adhere?
a. Fissures
b. Intrapulmonary bronchi
c. Lung
d. Mediastinum
Q. 3 Which of the following is the most important ventilatory function of the scalene muscles?
a. Activate if intrathoracic pressure falls to 40 cm H2O.
b. Elevate and fix the first seven ribs.
c. Lift upper chest particularly during times of high ventilatory demand.
d. Support the trachea within the thorax during heavy exercise.
Q. 4 As ventilatory muscles, the sternocleidomastoids do which of the following?
a. They elevate the upper chest, increasing chest anteroposterior diameter.
b. They elevate the ribs and decrease chest anteroposterior diameter.
c. They increase lateral chest movement dur-ing inspiration.
d. They lower the sternum, thus increasing chest anteroposterior diameter.
Q. 5 Which accessory muscles of ventilation work to pull the ribs closer together?
a. External intercostals
b. Internal intercostals
c. Scalenes
d. Sternocleidomastoids