Dead Space Review

Question 1

Absent or poor blood flow in alveolar capillaries results in (functional/non-functional) alveoli

Answer 1

Non-functional

Question 2

Non functional alveoli are included in the measurement of (physiologic/anatomical) dead space

Answer 2

Physiologic

Question 3

In lungs with non-functional alveoli, the physiological dead space may increase up to ___ times.

Answer 3

10

Question 4

In the case of increased physiological dead space, how is the V/Q ratio affected?

A. No change
B. Infinity (V= normal; Q is zero due to no blood flow)
C. Icreased (V=normal; Q is decreased)
D. Decreased (V=normal; Q is increased)

Answer 4

B. Infinity

Due to lack of perfusion in physiologic dead space, ventilation (V) continues, but perfusion (Q) is 0, resulting in V/0= infinity

*Can also occur in cardiac arrest

Question 5

Areas outside of alveoli that do not participate in gas exchange.

A. Physiological dead space
B. Anatomical dead space

Answer 5

B. Anatomical dead space