What occurs in the bases of the lung when a person is standing ...

[mpobi80]

What occurs in the bases of the lung when a person is standing upright?
 
  a. The PAO2 is higher than normal.
  b. The respiratory exchange ratio is elevated.
  c. There is significant dead space under normal conditions.
  d. The is lower than the average.

Question 2

Which of the following would you expect to occur if ventilation to an area of the lung remained constant but perfusion to this same area decreased?
 
  1. The PACO2 should fall.
  2. The PAO2 should fall.
  3. The ratio should rise.
  a. 3 only
  b. 1 and 2 only
  c. 1 and 3 only
  d. 1, 2, and 3

[nixon_s]

Answer to Question 1

ANS: D
At the bottom of the lung, blood flow is greater than ventilation, resulting in a low / (approxi-mately 0.66), low PO2 (89 mm Hg), and slightly higher PCO2 (42 mm Hg).

Answer to Question 2

ANS: C
A decrease in pulmonary capillary blood flow will cause a fall in alveolar PCO2 and a rise in al-veolar PO2 assuming minute ventilation remains the same. This will result in an area of high .

[mpobi80]

Excellent

[aruss1303]

TYSM