41.  What type of cells make up about 90% of the alveolar surface?  
A.  ciliated simple squamous epithelial cells
B.  Type I pneumocytes
C.  Type II pneumocytes
D.  macrophages

42.  What type of alveolar cells produce surfactant?  
A.  ciliated simple cuboidal epithelial cells
B.  Type I pneumocytes
C.  Type II pneumocytes
D.  macrophages

43.  What occurs at the respiratory membrane?  
A.  mucus removes debris
B.  gas exchange between the air and blood takes place
C.  macrophages accumulate to remove debris
D.  gas exchange between the blood and tissues takes place

44.  Which of the following is NOT part of the respiratory membrane?  
A.  simple squamous epithelium of the alveolus and its basement membrane
B.  interstitial space
C.  pulmonary capillary simple squamous epithelium and its basement membrane
D.  thick layer of mucus lining the alveolus

45.  Which of the following muscles increases the volume of the thorax during a normal inhalation?
(1) diaphragm
(2) external intercostals
(3) internal intercostals
(4) rectus abdominis  
A.  1, 2
B.  1, 3
C.  2, 3
D.  2, 4
E.  3, 4

46.  Contraction of the _______ will increase the superior-inferior dimension of the thoracic cavity.  
A.  rectus abdominis
B.  internal intercostals
C.  diaphragm
D.  external intercostals
E.  sternocleidomastoid

47.  Expiration during quiet breathing  
A.  is an active process.
B.  requires more muscle contractions than inspiration.
C.  is due to contraction of the diaphragm and elevation of the ribs.
D.  occurs when the diaphragm and external intercostal muscles relax.
E.  is not affected by the elastic properties of the lungs.

48.  Which of the following statements concerning the lungs and the pleura is true?  
A.  Each lung is suspended in a separate pleural cavity.
B.  Parietal pleura covers the surface of each lung.
C.  The space between the visceral and parietal pleurae is called the mediastinum.
D.  The pleural fluid assists in gas exchange.
E.  The pleural membranes adhere, but cannot slide past each other.

49.  The serous membranes that surround the lungs are called the  
A.  mucous membranes.
B.  synovial membranes.
C.  pleural membranes.
D.  peritoneal membranes.
E.  pulmonary membranes.

50.  Oxygenated blood is carried to the tissues of the lungs via the  
A.  pulmonary veins.
B.  bronchial arteries.
C.  pulmonary artery.
D.  abdominal aorta.
E.  pleural arteries.