Chapter 17 Mechanics of Breathing

Question 1

Cellular Respiration

Answer 1

cellular metabolism that consumes oxygen

Question 2

external respiration

Answer 2

exchange of gases between the atmosphere and cells of the body

Includes ventilation, gas exchange at the lung and cells, and transport of gases in the blood

Question 3

ventilation

Answer 3

movement of air into and out of the lungs

Question 4

respiratory system

Answer 4

consists of anatomical structures involved in ventilation and gas exchange

Question 5

upper respiratory tract

Answer 5

includes the mouth, nasal cavity, pharynx, and larynx

filters, warms, and humidifies inhaled air

Question 6

Lower respiratory tract

Answer 6

includes the trachea, bronchi, bronchioles, and exchange surfaces of the alveoli

Question 7

thoracic cage

Answer 7

bounded by ribs, spine, and diaphragm

Question 8

intercostal muscles

Answer 8

2 sets, connect the ribs

Question 9

pleural sac

Answer 9

the double membrane containing pleural fluid that surrounds the lungs

Question 10

alveoli

Answer 10

consists of type I alveolar cells, type II alveolar cells, and a network of capillaries surrounds each alveolus

Question 11

Type I alveolar cells

Answer 11

where gas exchange occurs

Question 12

Type II alveolar cells

Answer 12

produce surfactant

Question 13

Daltons law

Answer 13

the total pressure of a mixture of gases is the sum of the pressures of the individual gases in the mixture

Question 14

partial pressure

Answer 14

the pressure contributed by a single gas in a mixture

Question 15

Boyles law

Answer 15

as the volume of gas increases the gas pressure decreases.

the body creates pressure gradients by changing thoracic volume

Question 16

respiratory cycle

Answer 16

one inspiration through one expiration

Question 17

tidal volume

Answer 17

amount of air taken in during a single normal inspiration

Question 18

Vital capacity

Answer 18

Tidal volume + expiratory reserve volume + Inspiratory reserve volume

Question 19

residual volume

Answer 19

air volume in the lungs at the end of maximal expiration

Question 20

inspiration

Answer 20

alveolar pressure decreases

air flows into the lungs

requires contraction of the inspiratory muscles and the diaphragm

Question 21

expiration

Answer 21

usually passive

results from elastic recoil of the lungs

Question 22

active expiration

Answer 22

requires contraction of the internal intercostal and abdominal muscles

Question 23

intrapleural pressure

Answer 23

subatmospheric because the pleural cavity is a sealed compartment

Question 24

compliance

Answer 24

a measure of the ease with which the chest wall and lungs expand. Loss of compliance increases the work of breathing

Question 25

elastance

Answer 25

the ability of the lung to resist stretching or to return to its unstretched state

Question 26

surfactant

Answer 26

decreases surface tension in the fluid lining the alveoli

reduced surface tension prevents smaller alveoli from collapsing

makes it easier to inflate the lungs

Question 27

Resistance in the lungs

Answer 27

the diameter of bronchioles determines how much resistance they offer to airflow

Question 28

bronchoconstriction

Answer 28

parasympathetic neurons cause this in response to irritant stimuli

increased CO2 in expired air dilates bronchioles

Question 29

bronchodilation

Answer 29

no significant sympathetic innervation of bronchioles but epinephrine causes it.

Question 30

total pulmonary ventilation

Answer 30

=ventilation rate x tidal volume

Question 31

alveolar ventilation

Answer 31

=ventilation rate x (tidal volume - dead space volume)

Question 32

restrictive lung diseases

Answer 32

characterized by loss of compliance

Question 33

obstructive lung disease

Answer 33

have decreased air flow