L22: Pulmonary Ventilation & Gas Laws

Question 1

muscles for forced expiration

Answer 1

ab muscles

internal intercostals

Question 2

define total lung capacity

Answer 2

max volume of gas the lungs can hold

Question 3

lung capacity vs lung volume

Answer 3

combinations of lung volumes = lung capacity

lung volume is amount of air held in subdivisions of lungs

Question 4

tidal volume

Answer 4

vol of air that is inspired or expired w/ each breath at rest

500 ml

Question 5

inspiratory reserve volume

Answer 5

vol of air that can be inspired in addition to tidal vol w/ forceful inspiration
3000 ml

Question 6

expiratory reserve volume

Answer 6

additional vol of air that can be expired at end of tidal volume by forceful expiration
1100 ml

Question 7

residual volume

Answer 7

volume of air remaining in lungs after forceful expiration

1200 ml

Question 8

vital capacity

Answer 8

sum of all vol that can be inspired or exhaled
4600 ml

max inspiration + max expiration

Question 9

total lung capacity

Answer 9

vital capacity + residual vol

5800 ml

Question 10

inspiratory capacity

Answer 10

tidal vol + inspiratory reserve vol

3500 ml

Question 11

functional residual capacity

Answer 11

expiratory reserve vol + residual vol

2300 ml

Question 12

define minute ventilation

Answer 12

total volume of gases moved into and out of lungs per minute

Question 13

calculate minute ventilation

Answer 13

breaths/minute x tidal vol

= 8 L/min on average

(0.5 x breathing rate)

Question 14

define alveolar ventilation

Answer 14

total vol of gases that enter spaces participating in gas exchange per minute

Question 15

calculate alveolar ventilation

Answer 15

= breathing rate x (tidal vol - dead space)

=5600 ml/min on avg.

(0.35 x breathing rate)

Question 16

anatomical dead spaces

Answer 16

trachea
bronchi
bronchioles

Question 17

physiological dead space

Answer 17

anatomical dead space + ventilated alveoli w/ absent perfusion

Question 18

total dead space in normal humans

Answer 18

0.15 L

Question 19

what to consider when calculating dead space

Answer 19

ds does not participate in ventilation and contains negligible CO2

Question 20

respiratory bronchioles + perfused alveoli =

Answer 20

0.35 L

Question 21

tidal volume =

Answer 21

0.5 L

Question 22

define pleural pressure

Answer 22

pressure of the fluid between parietal pleura and the visceral pleura

measured in cm of water

Question 23

pleural pressure during inspiration

Answer 23

-5 to -7.5

Question 24

pleural pressure during expiration

Answer 24

-7.5 to -5

Question 25

define alveolar pressure

Answer 25

pressure of the air inside the alveoli

Question 26

alveolar pressure in inspiration vs expiration

Answer 26

in = 0 to -1

out = 0 to +1

Question 27

define transpulmonary pressure

Answer 27

difference between alveolar and pleural pressures

aka pressure resulting in the mvt of air in and out of lungs

Question 28

define compliance of the lungs

Answer 28

the volume/extend to which lungs will expand for each unit increase in the transpulmonary pressure

Question 29

normal compliance

Answer 29

200 ml of air per cm of water

Question 30

compliance of the lungs is a measure of the ?

Answer 30

expansibility of the lungs and trachea

Question 31

compliance formula

Answer 31

= increase in vol / increase in pressure

Question 32

define elastance

Answer 32

measure of tendency of a hollow viscus to recoil to its normal shape after being distended and such force is removed

ex. rubber band

Question 33

if surface tension was allowed in the lungs then

Answer 33

the alveoli would collapse

Question 34

components of surfactant

Answer 34

phospholipids
apoproteins
Ca ions

Question 35

surfactant is produced by

Answer 35

alveolar type II cells

Question 36

surfactant function

Answer 36

part dissolves

the rest spreads over the surface of the water in alveoli to protect them from collapse

Question 37

if air passages leading from the alveoli are blocked, then

Answer 37

surface tension will cause alveoli to collapse

creating positive pressure

Question 38

for average alveoli, pressure =

Answer 38

4 cm of water

Question 39

normal alveoli pressure is __, if there was no surfactant, pressure would be ?

Answer 39

4 cm of water
18
which is 4.5x as great

Question 40

what is the major component of air

Answer 40

N 78%

Question 41

list the 3 gas laws that relate to pulmonary function

Answer 41

daltons law
boyles law
henrys law

Question 42

the total pressure exerted by the mixture of non-reactive gasses is equal to the sum of the partial pressure of individual gasses

Answer 42

daltons law

Question 43

for a fixed amount of an ideal gas kept at a fixed temp, pressure and volume are inversely related

Answer 43

boyles law

Question 44

at a constant temp, the amount of a given gas that dissolves in a given type and volume of liquid is directly related to the partial pressure of that gas in equilibrium w/ that liquid

Answer 44

henry’s law

Question 45

gas law equation

Answer 45

PV = nRT

Question 46

define vapor pressure

Answer 46

vp of water is the partial pressure exerted to escape from the liquid phase to gas phase

Question 47

at normal body temp - vapor pressure =

Answer 47

47 mmhg

Question 48

as temperature increases, vapor pressure

Answer 48

increases

Question 49

list facts that affect rate of gas diffusion in a fluid

Answer 49

1. solubility of gas in the fluid
2. cross-sectional area of the fluid
3. distance thru which the gas must diffuse
4. molecular weight of the gas
5. temp of fluid