Ventilation and Associated Factors

Question 1

What is atmospheric pressure at sea level?

Answer 1

760 mmHg, referred to as 0

Question 2

The higher the altitude, the _____ the pressure.

Answer 2

lower

Question 3

What is the density of water close to the density of?

Answer 3

blood

Question 4

What is gauge pressure?

Answer 4

the pressure measured against zero atmospheric pressure

Question 5

How do you measure absolute pressure?

Answer 5

gauge pressure + atmospheric pressure

Question 6

What is the total pressure equal to according to Dalton’s law of partial pressures?

Answer 6

the sum of individual gasses in a mixture

Question 7

What does the difference in partial pressures allow for?

Answer 7

diffusion across the blood-gas membrane

Question 8

What is the label for airway or pleural pressure?

Answer 8

cm H2O/mmHg

Question 9

What is the label for pressure in blood vessels?

Answer 9

mmHg

Question 10

True or False: the pressure in the pleural cavity is usually negative.

Answer 10

True

Question 11

What is Boyle’s law?

Answer 11

P1V1=P2V2

Question 12

What does Boyle’s law mean?

Answer 12

pressure and volume are inversely related; when one increases, the other decreases

Question 13

What is Charle’s law?

Answer 13

V1/T1 = V2/T2

Question 14

What does Charle’s law mean?

Answer 14

the volume of a gas is directly proportionate to the temperature

Question 15

What is the ideal gas law?

Answer 15

PV=nRT

Question 16

What does P stand for in the ideal gas law?

Answer 16

gas pressure (atm)

Question 17

What does V stand for in the ideal gas law?

Answer 17

Volume (L)

Question 18

What does n stand for in the ideal gas law?

Answer 18

moles of gas

Question 19

What does R stand for in the ideal gas law?

Answer 19

the universal gas constant: 8,3145 J/mol K

Question 20

What does T stand for in the universal gas law?

Answer 20

Temperature (degrees K)

Question 21

Why is intrapleural pressure negative?

Answer 21

to allow for the alveoli to expand

Question 22

Which part of the respiratory cycle is active?

Answer 22

inspiration

Question 23

What happens during inspiration?

Answer 23

the diaphragm flattens, the inspiratory muscle contract, and the thoracic cavity expands

Question 24

What happens to the intrapleural pressure during inspiration?

Answer 24

it becomes more negative (-4 to -6 mmHg)

Question 25

What happens to the alveolar transmural pressure during inspiration?

Answer 25

it increases

Question 26

What happens to the alveoli during inspiration?

Answer 26

they expand at Palv = -1 mmHg

Question 27

When does air stop flowing during inspiration?

Answer 27

When Palv = 0 mmHg

Question 28

What is the passive phase of respiration?

Answer 28

expiration

Question 29

What happens to the body during expiration?

Answer 29

the diaphragm returns to dome shape, the inspiratory muscles relax, the internal intercostal and abdominal muscles contract, and the thoracic cavity returns back to normal size

Question 30

What happens to the intrapleural pressure during expiration?

Answer 30

it is less negative (-6 mmHg to -4 mmHg)

Question 31

What happens to the alveolar transmural pressure gradient during expiration?

Answer 31

it decreases

Question 32

What happens to the alveoli during expiration?

Answer 32

they return by elastic recoil (Palv = + 1 mmHg)

Question 33

When does air stop expiring?

Answer 33

when Palv = 0 mmHg

Question 34

What is Paw?

Answer 34

pressure within the airways

Question 35

What is Ppl?

Answer 35

pressure within the pleural cavity

Question 36

What happens if Ppl increases?

Answer 36

the lungs will not expand

Question 37

What promotes the recoil affect of alveoli?

Answer 37

the rebound of stretched elastin and collagen

Question 38

What reduces surface tension in alveoli?

Answer 38

surfactants hydrophilic and phobic moieties

Question 39

The smaller the diameter of the alveoli, the higher the ________.

Answer 39

pressure

Question 40

How is pressure reduced in small alveoli?

Answer 40

surfactant molecules being close to one another

Question 41

What prevents collapsing of alveoli?

Answer 41

alveolar interdependence and surfactant

Question 42

What alters alveolar interdependence?

Answer 42

emphysema

Question 43

How is compliance measured?

Answer 43

change in volume over change in pressure

Question 44

Compliance is the opposite of _____.

Answer 44

elasticity

Question 45

Define compliance.

Answer 45

the ease with which something could be stretched

Question 46

Define elasticity.

Answer 46

the tendency to come back to the original size/shape

Question 47

What disease causes compliance to decrease?

Answer 47

fibrosis

Question 48

What disease causes compliance to increase?

Answer 48

emphysema

Question 49

Characterize emphysema

Answer 49

high lung volume and small pressure change - widened alveoli

Question 50

What is hysteresis?

Answer 50

when the lung has inflated the surfactant molecules inflate, and it takes effort to open the alveoli

Question 51

What is Poisuelle's Law?

Answer 51

R = (8nl/pir^4)

Question 52

When r is decreased by 1/2, what happens to the new R?

Answer 52

it is increased by 16 fold