Anatomy of Chest Wall and Mechanics of Breathing

Question 1

What are the 4 gas laws?

Answer 1

Boyle’s law

Dalton’s law

Charles’ law

Henry’s law

Question 2

What does Boyle’s law state?

Answer 2

Pressure exerted by a gas is inversely proptional to its volume (P = 1/V)

Question 3

What does Dalton’s law state?

Answer 3

Total pressure of a gas mixture is the sum of the pressures of the individual gases

Question 4

What does Charles’ law state?

Answer 4

Volume occupied by a gas is sirected related to the absolute temperature (V directly proportional to T)

Question 5

What does Henry’s law state?

Answer 5

Amount of gas dissolved in a liquid is determined by the pressure of the gas and its solubility in the liquid

Question 6

When talking about the pressure and volumes of gas, what does the volume refer to?

Answer 6

The volume of the container that the gas is in

Question 7

What is core body temperature?

Answer 7

37^oC

Question 8

What is ventilation?

Answer 8

Movement of air in and out of the lungs

Question 9

In terms of pressure, where does air always move?

Answer 9

From areas of high pressure to areas of low pressure

Question 10

If the pressure in the lungs is more than the atmosphere, where does the air move?

Answer 10

From the lungs to the atmosphere (out of the body)

Question 11

What shape is the diaphragm?

Answer 11

Domed shaped

Question 12

What happens when the diaphragm contracts?

Answer 12

It flattens which increases the volume of the thoracic cavity

Question 13

How many lobes does the right and left lung have?

Answer 13

Right has 3 lobes

Left has 2 lobes

Question 14

What are the lobes in the right lung called?

Answer 14

Superior lobe

Middle lobe

Inferior lobe

Question 15

What are the lobes of the left lung called?

Answer 15

Superior lobe

Inferior lobe

Question 16

What is the pleural cavity critical for?

Answer 16

Maintaining the inflation state of our lungs

Question 17

What is A?

Answer 17

Aorta

Question 18

What is B?

Answer 18

Left lung

Question 19

What is C?

Answer 19

Pleural membranes

Question 20

What is D?

Answer 20

Left pleural cavity

Question 21

What is E?

Answer 21

Pericardial cavity

Question 22

What is F?

Answer 22

Right pleural cavity

Question 23

What is G?

Answer 23

Right lung

Question 24

What is H?

Answer 24

Esophagus

Question 25

What does the pleural cavity contain?

Answer 25

5mm of pleural fluid

Question 26

What is the pleural cavity unique to?

Answer 26

Each lung, they do not join

Question 27

What does the inside and outside of the pleural membrane line?

Answer 27

Ribs and outer tissue of the lungs

Question 28

What are the 2 pleural membranes called?

Answer 28

Visceral pleural membrane (lines lungs) Parietal pleural membrane (lines ribs)

Question 29

What does the visceral pleural membrane line?

Answer 29

Lungs

Question 30

What does the parietal pleural membrane line?

Answer 30

Ribs

Question 31

What are some functions of pleural fluid?

Answer 31

Act as lubricant, allowing the two membranes to glide across each other as the lungs expand and contract Create a force that stops the seperation of the lungs from the rib cage, so when the rib cage moves so does the lungs

Question 32

What is pleurisy?

Answer 32

Inflammation of pleural membranes

Question 33

What is inflammation of the pleural membranes called?

Answer 33

Pleurisy

Question 34

What is the pressure of the pleural cavity when the lungs are at rest?

Answer 34

-3mmHg

Question 35

Where does the rib cage and lungs naturally want to move?

Answer 35

Rib cage wants to move outwards and the lungs want to recoil inwards

Question 36

What happens to the intrapleural pressure when the lung is punctured?

Answer 36

Becomes equal to atmospheric pressure and the lung collapses

Question 37

What is the end of expiration a balance between?

Answer 37

The lung wanting to retract inwards and the ribcage wanting to expand outwards

Question 38

What creates the negative pressure of the pleural cavity?

Answer 38

Lung wanting to retract inwards and the ribcage wanting to expand outwards

Question 39

What is intrapleural pressure?

Answer 39

Negative pressure inside the pleural cavity

Question 40

What gas law is the mechanics of breathing based on?

Answer 40

Boyle's law Increase in volume decreases pressure Decrease in volume increases pressure

Question 41

What are the mechanics of breathing?

Answer 41

1 ) Thoracic cavity changes volume 2) This changes the pressure (Boyle's law) 3) Air moves from area of high pressure to low pressure

Question 42

What muscles does inspiration use?

Answer 42

Intercostal muscles Diaphragm

Question 43

What muscles does expiration use?

Answer 43

Is passive at rest, but during severe respiratory load uses: Internal intercostal muscles Abdominal muscles

Question 44

What is A?

Answer 44

Sternocleidomastoids

Question 45

What is B?

Answer 45

Scalenes

Question 46

What is C?

Answer 46

External intercostals

Question 47

What is D?

Answer 47

Diaphragm

Question 48

What is E?

Answer 48

Abdominal muscles

Question 49

What is F?

Answer 49

Internal intercostals

Question 50

Where do external intercostals run between and what happens when they contract?

Answer 50

Ribs When they contract they lift the rib cage upwards and outwards

Question 51

Where do internal intercostal muscles run between, and what do they do when they contract?

Answer 51

Ribs When they contract they lift they pull the ribcage inwards and downwards

Question 52

What happens when abdominal muscles contract?

Answer 52

They bring abdominal organs upwards, which push agaist the diagragm and decreases thoracic volume

Question 53

What does the diaphragm do during inspiration?

Answer 53

Contracts and flattens which increases thoracic volume

Question 54

What does the diaphragm do during expiration?

Answer 54

Relaxes which decreases thoracic volume

Question 55

What can thoracic volume increasing due to rib movement be compared to?

Answer 55

Bucket handle shows increase in lateral dimensions Pump handle shows increase in anterior-posterior dimensions

Question 56

What can the ribs causing an increase in lateral dimensions be compared to?

Answer 56

Bucket handle

Question 57

What can the ribs causing an increase in anterior-posterior dimensions be compared to?

Answer 57

Pump handle

Question 58

What is asthma?

Answer 58

Over reactive constriction of bronchial smooth muscle, increasing resistance

Question 59

Why do asthma sufferers struggle during expiration but not inspiration?

Answer 59

Physical forces pull airways open during inspiration but not expiration

Question 60

What is pneumothorax?

Answer 60

Collapsed lung, occuring due to air leaking into the pleural cavity and altering the pressure (equal to atmospheric pressure)

Question 61

What is a collapsed lung called?

Answer 61

Pneumothorax

Question 62

What happens during pneumothorax?

Answer 62

Rib cage expands slightly and lung collapses to unstretched size due to no longer being attached by the force created by the pleural cavity

Question 63

Why does a pneumothorax happen?

Answer 63

Punctured pleural cavity causes loss of negative pressure as it becomes equal to the atmosphere Force that attaches lungs to rib cage is no longer present and so the lung collapses to unstretched size

Question 64

What are 3 relative pressures?

Answer 64

Intra-thoracic (alveolar) pressure, P_A Intra-pleural pressure, P_IP Transpulmonary pressure, P_T

Question 65

What is intra-thoracic (alveolar) pressure, P_A?

Answer 65

Pressure inside the thoracic cavity (inside lungs) May be negative or positive

Question 66

What is intra-pleural pressure, P_IP?

Answer 66

Pressure inside the pleural cavity Always negative

Question 67

What is transpulmonary pressure, P_T?

Answer 67

Pressure difference between the alveolar and intra-pleural pressure P_T = P_A - P_IP Always positive because intra-pleural pressure is always more negative than alveolar pressure

Question 68

What is intra-pleural pressure compared to alveolar pressure?

Answer 68

Always more negative

Question 69

How does pressure change during the respiration cycle?

Answer 69

During inspiration alveolar pressure goes negative then back to 0 and intrapleural pressure goes more negative During expiration alveolar presure goes positive and then back to 0 and intrapleural pressure goes closer to 0

Question 70

What formula describes the flow of air?

Answer 70

Directly proportional to the difference between atmospheric and alveolar pressure and inversely proportional to airway resistance: F = (P_ATM - P_A / R

Question 71

How does alveolar pressure compare to atmospheric pressure at the end of an unforced expiration?

Answer 71

P_ATM = P_A

Question 72

Why are the dimensions of the thoracic cage stable after an unforced expiration?

Answer 72

Opposing elastic forces are equal, creating subatmospheric intrapleural pressure and a transpulmonary pressure that opposes the forces of elastic recoil

Question 73

What is the most important thing affecting airway resistance?

Answer 73

Radii of airway