Lecture 16: Mechanics, lung volumes, ventilation

Question 1

Pulmonary Ventilation

Answer 1

alternating flow of air into and out of lungs

due to actions of various resp. muscles

Question 2

Inspiratory muscles function

Answer 2

expand rib cage

drive airflow INTO lungs

Question 3

expiratory muscles function

Answer 3

depress rip cage
force air OUT of lungs
passive process
diaphragm is relaxed (dome shape)

Question 4

Thoracic cage includes

Answer 4

ribs
costal cartilages
thoracic vertebrae
sternum

Question 5

Respiratory Mechanics

Answer 5

how resp. muscles move the rib cage

Question 6

respiratory pump

Answer 6

resp muscles, rib cage, pleural membranes, lung elastic tissues
designed to change shape of rib cages
causes pleural membranes to move out, dec pleural fluid, lungs out as well

Question 7

Inspiratory Muscles (list)

Answer 7

diaphragm (primary)
external (and internal) intercostals (secondary)
move ribs up and out, expand rib cage
Sternocleidomastoid: elevate sternum
sclaenes: elevate top two ribs

Question 8

Expiratory Muscles (list)

Answer 8

internal intercostals: pull ribs down and in, dec dimater of rib cage
Abdominal muscles: depress lower ribs, elevate diaphragm up into thorax
reduce throacic diameter and force air out of lungs
inc pressure in lungs

Question 9

Inspriation pressure

Answer 9

pressure in lungs LOWER than pressure in atmosphere

Question 10

Expiration pressure

Answer 10

pressure in lungs HIGHER than pressure in atmosphere

Question 11

Respiratory mechanics

Answer 11

ventialtion depends on periodic pressure changes in lungs

Question 12

Pressure changes in lungs depend on…

Answer 12

pleural membranes!

Question 13

Inspeiration respiroatory mechanics ex

Answer 13

parietal pleura pulled outward
visceral pleura moves with it
so do lungs

Question 14

Transpulmonary Pressure (P tp) equation

Answer 14

Ptp= Palv- Pip

Question 15

Pip

Answer 15

intra plural pressure

space that surrounds lungs

Question 16

Palv

Answer 16

intraalveolar pressure
pressure in alveoli
aka intrapulmonary pressure

Question 17

Transpulmonary Pressure (P tp)

Answer 17

diff between Pip and Palv

cjamge pressure of plureal flud to affect lung pressure

Question 18

pleural fluid pressure

Answer 18

NEGATIVE

so lungs don’t collapse

Question 19

why lungs want to collapse

Answer 19

made from elastic tissue

Question 20

inspiration begins

Answer 20

contraction of diaphragm

Question 21

contraction of diagphragm causes thoracic cage to

Answer 21

enlarge

INSPIRATION

Question 22

when thoracic cage enlarges…

Answer 22

interpleural pressure decreases

INSPIRATION

Question 23

when interpleural space decreases

Answer 23

alveolia open
air pressure in alveoli decreases
INSPIRATION

Question 24

pressure gradeint of air in inspiration

Answer 24

atmosphere down to lungs

INSPIRATION

Question 25

when diaphragm relaxes

Answer 25

elastic tissue in lungs go inward

Question 26

lungs recoil... air

Answer 26

is compressed alveolar pressure rises ABOVE ATMOSPHERIC PRESSURE EXPIRATION

Question 27

pressure gradeint of air in inspiration

Answer 27

lungs out to atmopshere

Question 28

End expiratory lung volume is the

Answer 28

period between breaths

Question 29

during the end expiratory lung volume... relationship of pressures

Answer 29

atmospheric pressure=alveolar pressure pleural pressure is less than atmopheric pressure WHY? Lung wants to collapse all the time more pull=greater negative volume

Question 30

recoil direction of chest wall

Answer 30

outward

Question 31

recoil direction of lungs

Answer 31

inward

Question 32

opposing forces of chest wall and lungs result

Answer 32

negative pleural pressure | pull lung tissue to keep it from deflating

Question 33

Spirometers meassure

Answer 33

``` lung volume subdivisions: vital capacity residual volume expiratory reserve volume inspiratory reserve volume tidal volume total lung capacity Inspiratory capacity FRC? ```

Question 34

Functional residual capacity (FRC)

Answer 34

volume that fresh air MUST mix with in order to inc lung O2 stores and dec lung CO2 stores ERV+RV

Question 35

Large FRC

Answer 35

labored breathing | obstructive lung diseases (athsma, COPD)

Question 36

small FRC

Answer 36

large fluctuations in O2 and CO2 inspiratory restiction expiratory restriction

Question 37

too little CO2 makes you

Answer 37

light headed

Question 38

Lung Compliance def

Answer 38

ease at which lungs are inflated

Question 39

lung compliane equation

Answer 39

delta Vl/ delta Ptp

Question 40

things that decrease compliance

Answer 40

asbetosis | things that thicken or stiffen lung tissue

Question 41

things that increase compliance

Answer 41

emphysema very compliant lung because of breakdown of alveolar tissues, result in connected alveoli air gets trapped some places raises FRC as well

Question 42

Pulmonary ventilation

Answer 42

rate of lung ventilation

Question 43

Pulmonary ventilation (l/min) equation

Answer 43

tidal vol (L/breath) X breathing freq (breath/min)

Question 44

alveolar ventilation

Answer 44

air that ACTUALLY ventialtes alveoli

Question 45

alveolar ventilation equation (L/min)

Answer 45

(tidal vol-dead space vol) X breathing frequency (l/breath) X (breath/min) dead space= everywhere but resp. bronchioles and alveoli