Chapter 17 Mechanics Of Breathing

Front 1

aerobic metabolism

Back 1

in living cells, consumes oxygen and produces C02

Front 2

gas exchange

Back 2

requires a large, thin, moist exchange surface; a pump to move air; and a circulatory system to transport gases to the cells

Front 3

respiratory system functions

Back 3

include gas exchange, pH regulation, vocalization, and protection from foreign substances, venous return

Front 4

cellular respiration

Back 4

refers to cellular metabolism that consumes oxygen (tissues or living cells)

Front 5

external respiration

Back 5

is the exchange of gases between the atmosphere and cells of the body. It includes ventilation, gas exchange at the lung and cells, and transport of gases in the blood. (breathing)

Front 6

pulmonary ventilation

Back 6

is the movement of air into and out of the lungs

Front 7

respiratory system

Back 7

consists of anatomical structures involved in ventilation and gas exchange.

Front 8

gas exchange site

Back 8

in alveoli

Front 9

upper respiratory tract

Back 9

includes mouth, nasal cavity, pharynx and larynx

Front 10

lower respiratory tract

Back 10

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

Front 11

thoracic cage

Back 11

is bounded by the ribs, spine and diaphragm

Front 12

intercostal muscles

Back 12

two sets _____ connect the ribs

Front 13

pleural fluid

Back 13

each lung is contained within a double-walled ________ _______

Front 14

primary bronchi

Back 14

the 2 ___ ____ enter the lungs. Each divides into progressively smaller bronchi and finally into collapsible bronchioles

Front 15

Type I alveolar cells

Back 15

the alveoli consist mostly of thin-walled ______ for gas exchange.

Front 16

Type II alveolar cells

Back 16

produce chemicals called surfactant which helps prevent the alveoli from collapsing.

Front 17

a network of capillaries

Back 17

surrounds each alveolus.

Front 18

blood flow through the lungs=

Back 18

cardiac output

Front 19

resistance blood flow in pulmonary circulation is

Back 19

low

Front 20

pulmonary arterial pressure averages

Back 20

25/8 mmHg

Front 21

blood vessels cover

Back 21

approximately 80-90% of the alveolar surface

Front 22

in the lungs blood flow is

Back 22

higher and blood pressure is lower in comparison to other tissues.

Front 23

Dalton's Law

Back 23

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

Front 24

partial pressure

Back 24

is the pressure contributes by a single gas in a mixture

Front 25

bulk flow of air

Back 25

occurs down pressure gradients, as does the movement of any individual gas making up the air

Front 26

Boyle's law

Back 26

states that as the volume available to gas increases, the gas pressure decreases.

Also gas volume is inversely proportional to pressure.( the more space, the pressure decreases)

Front 27

Tidal volume (TD)

Back 27

is the amount of air taken in during a single normal inspiration

Front 28

vital capacity

Back 28

is tidal volume plus expiratory and inspiratory reserve volumes.

Front 29

residual volume

Back 29

air volume in the lungs at the end of maximal expiration

Front 30

Inspiratory Reserve Volume (IRV)

Back 30

the additional air inhaled after a normal inspiration

Front 31

Expiratory reserve volume (ERV)

Back 31

extra amount forcibly exhaled after normal exhalation

Front 32

Residual Volume (RV)

Back 32

minimum air always present in the respiratory system after blowing out all you can

Front 33

Total lung capacity (TLC)

Back 33

TV + RV + IRV+ERV

Front 34

the upper resp system

Back 34

filters, warms and humidifies inhaled air

Front 35

air flow in the resp system

Back 35

is directly proportional to the pressure gradient, and inversely related to the resistance to air flow offered by the airways.

Front 36

respiratory cycle

Back 36

a single ____ ______ consists of an inspiration and expiration

Front 37

during inspiration

Back 37

alveolar pressure decreases and air flows into lungs

Front 38

inspiration requires

Back 38

contraction of the inspiratory muscles and the diaphragm

Front 39

expiration

Back 39

is usually passive, resulting from elastic recoil of the lungs

Front 40

active expiration

Back 40

requires contraction of the internal intercostals and abdominal muscles

Front 41

intrapleural pressures

Back 41

are always sub-atmospheric because the pleural cavity is a sealed compartment

Front 42

compliance

Back 42

is the ease with which the chest wall and lungs expand

Front 43

loss of compliance

Back 43

increases the work of breathing

Front 44

elastance

Back 44

is the ability of a stretched lung to return to its normal volume

Front 45

surfactant

Back 45

decreases surface tension in the fluid lining the alveoli. this prevents smaller alveoli from collapsing

Front 46

diameter of bronchioles

Back 46

determines how much resistance they offer to air flow

Front 47

increased C02 in expired air

Back 47

dilates bronchioles

Front 48

parasympathetic neurons

Back 48

cause bronchoconstriction in response to irritant stimuli

Front 49

bronchodilation

Back 49

there are no significant sympathetic innervations of bronchioles, but epinephrine causes ______

Front 50

total pulmonary ventilation

Back 50

= tidal volume x ventilation rate

Front 51

alveolar ventilation

Back 51

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

Front 52

alveolar gas composition

Back 52

changes very little during a normal respiratory cycle

Front 53

hyperventilation

Back 53

increases alveolar P02 and decreases alveolar Pco2

Front 54

hypoventilation

Back 54

decreases alveolar P02 and increases alveolar Pco2

Front 55

local mechanisms

Back 55

airflow is matched to blood flow around the alveoli by ____ _____

Front 56

increased levels of C02

Back 56

dilate bronchioles

Front 57

decreased 02

Back 57

constricts pulmonary arterioles