Chapter 12

Question 1

which organ receives the largest blood supply?

Answer 1

alveoli

Question 2

what is the function of the pores of kohn?

Answer 2

evenly disperse surfactant over respiratory membranes to reduce surface tension for easier alveolar inflation

Question 3

what are the 2 zones of ventilation?

Answer 3

1. conducting zones

2. transitional and respiratory zones

Question 4

what are the conducting zones? what is its function?

Answer 4

trachea and terminal bronchioles

anatomic dead space

functions in air transport, humidification, warming, particle filtration, vocalization, and immunoglobulin secretion

Question 5

what are the transitional and respiratory zones? what is its function?

Answer 5

bronchioles, alveolar ducts, and alveoli

functions in gas exchange, surfactant production, molecule activation and inactivation, blood clotting regulation, and endocrine function

Question 6

what is Fick’s law of diffusion?

Answer 6

the pressure differential between air in lungs and lung-chest wall interface causes lungs to adhere to the chest wall and follow its movement

Question 7

gas diffuses through a sheet of tissue at a rate…?

Answer 7

directly proportional to tissue area, a diffusion constance, and pressure differential of the gas on each side of the membrane

inversely proportional to tissue thickness

Question 8

what are the 3 phases of inspiration?

Answer 8

diaphragm contracts and flattens

chest cavity grows causing pressure to slightly decrease below atmospheric pressure

lungs inflate

Question 9

what are the 2 phases of expiration

Answer 9

sternum and ribs drop

diaphragm rises

Question 10

how does air move out of the lungs?

Answer 10

natural recoil of stretched lung tissue and relaxation of inspiratory muscles

Question 11

what is residual lung volume? what is its importance?

Answer 11

air volume remaining in the lungs after forced maximal exhalation

allows uninterrupted exchange of gas between blood and alveoli to prevent fluctuations in blood gases during phases of the breathing cycle

Question 12

how do you calculate total lung capacity (TLC)?

Answer 12

residual lung volume (RLV) + FVC

Question 13

what is dynamic lung volume dependent on?

Answer 13

maximum “stroke volume” of the lungs (FVC)

speed of moving a volume of air (breather rate)

determined by lung compliance

Question 14

what are dynamic lung tests useful for? *

Answer 14

indicates severity of obstructive (air out) and/or restrictive (air in) lung disease

Question 15

how do you increase inspiratory muscle function and maximum voluntary ventilation?

Answer 15

training ventilatory muscles which improves their strength and endurance

Question 16

what are the differences in lung functions between males and females?

Answer 16

females have reduced lung size and airway diameter, smaller diffusion surface, and lower static and dynamic lung function measures

Question 17

what are the 2 perspectives of pulmonary ventilation? *

Answer 17

1. volume of air moved into or out of the VE respiratory tract each minute
2. air volume that ventilates only alveolar chambers each minute

Question 18

how do you calculate minute ventilation (Ve)?

Answer 18

VE = breathing rate x tidal volume

Question 19

what is minute ventilation?

Answer 19

the volume of air breathed each minute

Question 20

what is anatomic dead space? *

Answer 20

air in each breath that does not enter alveoli and participate in gaseous exchange with blood

Question 21

what is alveolar ventilation? *

Answer 21

portion of inspired air reaching the alveoli and participating in gas exchange

Question 22

what is the ventilation-perfusion (V-P) ratio?

Answer 22

the ratio of alveolar ventilation to pulmonary blood flow

Question 23

what is the average ventilation-perfusion ratio?

Answer 23

0.84 L/min blood flow

Question 24

what are 2 factors that prevent alveoli from functioning adequately in gas exchange?

Answer 24

1. underperfusion of blood

2. inadequate ventilation relative to alveolar surface

Question 25

what happens to breathing and alveolar ventilation during exercise?

Answer 25

breathing becomes deeper

alveolar ventilation increase from 70% to >85% of exercise minute ventilation

Question 26

what is hyperventilation? *

Answer 26

decrease in FEO2 (fractioned expiratory O2)

increase in pulmonary ventilation that exceeds to O2 consumption and CO2 elimination needs of metabolism

Question 27

what is dyspnea?

Answer 27

inordinate shortness of breath or subjective breathing distress

Question 28

what is the valsalva maneuver? *

Answer 28

closing glottis following a full inspiration while maximally activating expiratory muscles

creates compressive force that increase intrathoracic pressure above atmospheric pressure

stabilizes abdominal and thoracic cavities

Question 29

what is FEO2?

Answer 29

when you are blowing off more O2 than you need

indicator of changes in thresholds (aerobic)

Question 30

what happens when you perform the valsalva maneuver? *

Answer 30

reduces return of blood to the heart because increased intrathoracic pressure collapses inferior vena cava that runs through chest cavity