Natalie - Pulmonary Pressures

Question 1

Define pulmonary ventilation

Answer 1

The physical movement of air into and out of the lungs

Question 2

What two things does the movement of air depend on?

Answer 2

Boyle’s Law
Compliance

Question 3

What is Boyle’s Law

Answer 3

The pressure and volume of a gas are inversely proportional at constant temperature and volume

Question 4

Define lung compliance
(2)

Answer 4

A measure of the ease at which our lungs can stretch

An indication of the expandability of the lungs

Question 5

Describe the movement of air in relation to pressure

Answer 5

Air moves from high to low pressure

Question 6

What pressures determine the direction of air flow in the lungs?

Answer 6

The relationship between the intra-pulmonary pressure and the atmospheric pressure determines the direction of air flow

Question 7

What pressures determine the direction of air flow in the lungs?

Answer 7

The relationship between the intra-pulmonary pressure and the atmospheric pressure determines the direction of air flow

Question 8

What is the intra-pulmonary pressure

Answer 8

Pressure inside the alveoli

Question 9

What is the intra-pulmonary pressure

Answer 9

Pressure inside the alveoli

Question 10

What is intra pleural pressure?

Answer 10

Pressure in the pleural cavity

Question 11

What does intra-pleural pressure control?

Answer 11

It maintains pull on the lungs

Question 12

List the three different types of pressures

Answer 12

Intra-alveolar/pulmonary pressure (pressure in the alveoli)

Atmospheric pressure

Intra-pleural pressure

Question 13

What happens to the volume of the thorax during inhalation?

Answer 13

The volume increases during inhalation

Question 14

What happens to the pressure in the lungs during inhalation and why?

Answer 14

Pressure decreases because the volume of the thorax increases (lungs expand and fill with air but have more room therefore less pressure)

Question 15

What happens to the pressure in the lungs during exhalation

Answer 15

Volume of thorax decreases - air forced out of lungs so pressure increases

Question 16

What pressure is responsible for keeping the lungs open?

Answer 16

Intra-pleural pressure

Question 17

List the three pulmonary pressures

Answer 17

Intra alveolar pressure

Intra pleural pressure

Trans pulmonary pressure

Question 18

Define tidal volume

Answer 18

The volume of air taken into the lungs at rest
Approximately 500 mls

Question 19

Write a note on intra pleural pressure
(4)

Answer 19

It is always negative, never positive

If it goes above zero the lung collapses

Pressure must be lower than atmospheric pressure

Lower than alveolar pressure - allows alveoli to stay open - keeps about 1L of air in the lungs which never leaves

Question 20

What are the two phases to breathing

Answer 20

Inhalation
Exhalation

Question 21

What is inhalation?

Answer 21

Air is pulled into the lungs

Question 22

What is exhalation?

Answer 22

Air is pushed out of the lungs

Question 23

What is the overall function of breathing?

Answer 23

To deliver oxygen to the alveoli

To remove carbon dioxide

Question 24

Define breathing

Answer 24

The continuous cycle of inhalation and exhalation

Question 25

What is respiratory rate?

Answer 25

Amount of breaths per minute Average = 10 to 15

Question 26

What happens when the diaphragm contracts?

Answer 26

The diaphragm moves down - pulls lungs down - pulls air into lungs - inhalation

Question 27

What happens when the diaphragm relaxes?

Answer 27

The diaphragm moves up - pushes lungs up - pushes air out of lungs - exhalation

Question 28

State Boyle's Law

Answer 28

For a given quantity of any gas (such as air) in a container, the pressure is inversely related to the volume of the container

Question 29

What happens to intra-pleural pressure as we inhale?

Answer 29

It gets more negative as we inhale as pleural fluid doesn't expand (so its pressure drops)

Question 30

What are two other names for intra-alveolar pressure?

Answer 30

Intra pulmonary pressure Intra thoracic pressure

Question 31

What two factors determine intra alveolar pressure?

Answer 31

Amount of air in the alveoli The volume of the alveoli themselves

Question 32

What is the loss of alveoli called?

Answer 32

Atelectasis

Question 33

Why is pressure exerted outwards in the lung?

Answer 33

Pressure in the alveoli is higher than the intra pleural pressure

Question 34

What happens to intra alveolar pressure during inhalation?

Answer 34

It decreases slightly but does NOT go below intra pleural pressure

Question 35

What is trans pulmonary pressure?

Answer 35

The difference between the intra alveolar and intra pleural pressure

Question 36

What happens to the trans pulmonary pressure during inhalation?

Answer 36

It increases during inhalation

Question 37

What is a pneumothorax (3)

Answer 37

Pneumothorax occurs when air leaks from inside of the lung to the space between the lung and the chest wall. The lung then collapses It is the presence of air within the pleural space

Question 38

What happens to pulmonary pressures during a pneumothorax?

Answer 38

Pressure is exerted INWARDS Alveolar pressure lowers below intra pleural pressure (which increases)