Question

1. Which of the following is the factor responsible for the natural recoil of the lung?

A. Elastic fibers in the lung

B. Fluid surface tension

C. Surfactant

D. Both a and b

2. Which of the following statements regarding oxygen level and respiratory rate is true?

A. The most potent chemical in controlling respiratory rate

B. A small change in oxygen levels create changes in respiratory rate

C. Large drops of oxygen must be present to influence rate

D. Both a and b

3. A patient presests with a severe longstanding anemia. She is finally diagnosed as having severe iron deficiency anemia. She is given iron supplement. Which of the following would be expected?

A. Rise in ferritin

B. Rise in reticulocytes

C. Decrease in cell size

D. Both a and b

4.An 18 year old presents with acute panic attack. Her respirations are rapid and deep. She complains of having tingling around her lips and her fingers. Which of the following is the most likely the cause of her symptoms?

A. Increase in oxygen in her blood

B. Blood has become acidic from carbon dioxide retention

C. Blood has become alkalotic becuase she is blowing off her carbon dioxide

D. It is all in her head

5. Which of the following is not a chemotaxic enzyme?

A. Viral toxins

B. Histamine

C. Products of complement activation

D. Products of serum clotting activation

Answer 1

1). D. Both a and b

Elastic recoiling of the lungs is the ability to retain their shape after being stretched by the deep inhalation of air. During exhalation (passive process), the diaphragm and the intercostal muscles relax. The size of the chest cavity decreases and the pressure in the lungs increases which allows the air out. This phenomenon is supported by the elastic fibers of lung’s connective tissue and the surface tension of the fluid film covering the alveolar surface.