module 11 ventilation

Question 1

ventilation

Answer 1

moving air into lungs and distributing to gas exchange units

• minure ventilation
• alveolar ventilation

Question 2

measurements of ventilation

Answer 2

lung volumes

lung capacities

Question 3

tidal volume

Answer 3

normal breath during inhalation and exhalation

- approx. 500 mL

Question 4

inspiratory reserve volume

Answer 4

amount of gas a person is able to inspire above normal breath (maximum breath)
- approx. 3L

Question 5

Expiratory reserve volume

Answer 5

amount of gas expired beyond tidal volume

- approx. 1.2L

Question 6

residual volume

Answer 6

volume of gas left in lungs at end of maximal expiration

- approx. 1.2L

Question 7

Vital capacity

Answer 7

total volume of gas that can be exhaled during maximal expiration
- approx. 4.8L 
includes:
- inspiratory reserve volume
- tidal volume 
- expiratory reserve volume

Question 8

inspiratory capacity

Answer 8

amount of gas that can be inspired form a resting expiration
-approx. 3.5L

Question 9

functional residual capacity

Answer 9

amount of gas left in lungs at end of a normal expiration

• approx. 2.4L
  includes:
• expiratory reserve volume and residual volume

Question 10

total lung capacity

Answer 10

amount of gas contain in lungs at maximal inspiration

- approx. 6L

Question 11

dead space

Answer 11

3 demensions

• anatomic
• alveolar
• physiologic

Question 12

anatomic dead space

Answer 12

conduction airways

• volume of gas in conducting airways not used for gas exchange
• nose to bronchioles
• 1L per lb of ideal body wt in adult

Question 13

alveolar dead space

Answer 13

ventilated but unperfused area of lung

- wasted ventilation

Question 14

physiologic dead space

Answer 14

functional dead space

• sum of anatomic and alveolar
• approx. 1/3 of each breath is dead space

Question 15

Minute ventilation

Answer 15

associated with tidal volume

- air with each breath: 500mL

Question 16

hypoventilation

Answer 16

decreased rate/depth of respiration
PaCO2 > 45
delivery of air to alveoli is inadequate to provide O2 and remove CO2
-> hypoxemia d/t inc. alveolar CO2 with displaces O2

Question 17

causes of hypoventilation

Answer 17

CNS depressing drugs
myasthenia gravis
obesity
pain 
chest wall damage
paralysis of respiratory muscles 
morphine
barbituates

Question 18

hyperventilation

Answer 18

increased rate and dec. depth of respiration
PaCO2 < 35
inc. air in alveoli -> hypocapnia
-> shift to left: inc. affinity for O2

Question 19

Causes of hyperventilation

Answer 19

fever
brainstem injury
high altitude
anxiety 
pain
hypoxic stimulation of peripheral chemoreceptors

Question 20

ineffective gas exchange d/t ventilatory failure occurs:

Answer 20

adequate gas maldistribution
minute ventilation dec.
alveolar hypoventilation occurs