Ventillation Ad Gas Exchange

Question 1

Tidal volume

Answer 1

Amount of air going in an out with each breath normally 500ml

Question 2

Inspiratory reserve volume

Answer 2

Extra amount of volume you can get into lung on top of tidal volume

Question 3

Expiratory reserve volume

Answer 3

Amount of air that can empty past tidal volume

Question 4

Residual volume

Answer 4

Can fully empty lungs out due to lungs holding their structure which prevent collapse

Question 5

Vital capacity

Answer 5

Difference between max air you can get into lungs and min air

Question 6

Functional residual capacity

Answer 6

Everything below default position of lung capacity e.g. if you take in a deep breath and die, your lungs won’t empty all the way to bottom since that takes muscle effort, but to a baseline level due to elastic fibres of lung recoiling

Question 7

Inspiratopry capacity

Answer 7

Everything above baseline value
Max volume of air a person can breathe after tidal volume

Question 8

What factors affect lung volume and capacity

Answer 8

• Body and Size - The taller someone is, the larger their lungs (weight is not a factor)
• Sex - Average male has larger lung volume than the average female
• Disease - Can cause breakdown of the tissue inside
• Age - Older you are, lower the lung volume
• Fitness -If you have athletic parents, you are more likely to have larger lungs than someone w/o them

Question 9

Dead space

Answer 9

Anatomical dead space is equivalent to conducting zone
Alveolar dead space is equivalent to non perfused parenchyma
Respiratory zone is where gas exchange occurs
Where gas exchange doesn’t occur

Question 10

2 procedures that can decrease volume of someone’s dead space

Answer 10

Tracheostomy
Cricothyrocotomy

Question 11

2 procedures that can increase volume of dead space

Answer 11

Snorkeling
Anaesthetic circuit

Question 12

• What tendency does the chest wall vs lungs have to move?

Answer 12

Chest wall has tendency to spring outwards and lung has tendency to recoil inwards

Question 13

When are recoiling forces equal

Answer 13

At end tidal expiration

Question 14

Changes resulting in inspiration and expiration

Answer 14

Inspiratory muscle effort+chest recoil>lung recoil

Chest recoil<lung recoil +expiratory muscle effort

Question 15

Membrane surrounding lungs

Answer 15

Visceral pleural membrane

Question 16

Membrane covering inner surface of chest wall

Answer 16

Parietal pleural membrane

Question 17

Pleural cavity

Answer 17

The gap between the pleural membranes which is a fixed volume

Question 18

Pleural cavity contains

Answer 18

Protein rich pleural fluid

Question 19

Which 2 conditions can compromise

Answer 19

Haemothorax where intrapleural bleeding occurs reducing ventilation ability

Pneumothorax were perforated chest wall causes lungs to collapse

Question 20

Negative pressure gradient

Answer 20

Diaphragm is pulled down and rib cage out which reduces alveolar pressure below atmospheric pressure
Air flow into lungs
Normal breathing

Question 21

Positive pressure breathing’s

Answer 21

When pressure in atmosphere is increased above alveolar pressure so air is forced into lung
Mechanical ventilation or cpr or fighter pilot

Question 22

Diaphragm and respiratory muscles

Answer 22

Diaphragm creates pulling force when contracted
External intercostal muscle contract pulling rib cage in upwards and outward direction

Question 23

Dalton’s law

Answer 23

Pressure of gas mixture is equal to some of partial pressure of gases in mixture

Question 24

Ficks law

Answer 24

Molecules diffuse from high to low conc
Exchange SA and diffusion capacity inversely proportional to thickness of exchange surface

Question 25

Henry’s law

Answer 25

At constant temp the amount of gas that dissolves jn a liquid is directly proportional to partial pressure of gas in equilibrium

Question 26

Boyles law

Answer 26

At a constant temp the volume of a gas is inversely proportional to pressure of gas

Question 27

Charles law

Answer 27

At constant pressure volume of a gas is proportional to temperature of gas

Question 28

In accordance to Charles law which volume of air is slightly larger

Answer 28

Volume of expired air is larger as it is wet

Question 29

How does composition of air being breathed in change when on oxygen therapy

Answer 29

Increase in oxygen partial pressure
Rest stay the same

Question 30

How does composition of air change when on house fire

Answer 30

Decrease in oxygen partial pressure
Increase in carbon dioxide
Increase in carbon monoxide

Question 31

High altitude

Answer 31

Composition stays the same but volume of each gas inhaled decreases

Question 32

Inspired gas modifications

Answer 32

Warmed humidified slowed and mixed

Question 33

Oxygen delivery

Answer 33

16mL/min
We need 250mL/min at rest so relying on dissolved oxygen isn’t enough

Question 34

What type of protein is haemoglobin

Answer 34

Allosteric

Question 35

When does right shift occur

Answer 35

Increased temp
Acidosis
Increased 2,3 DPG
Hypercapnia-higher pco2
Right shift means decreased affinity for oxygen

Question 36

Left shift

Answer 36

Decreased temperature
Alkalosis
Hypocapnia
Decreased 2,3-DPG

Question 37

Oxygen flux

Answer 37

Change in oxygen content in blood after unloading

Question 38

Co2 loading

Answer 38

Moves just to blood where it binds to water making carbonic acid
Thus dissociated into bicarbonate
Thus moves out of blood and cl- moves j
Also bu do to Hb at amine end to make carb amino haemoglobin

Question 39

How is Hb a good buffer

Answer 39

It binds to protons that carbonic acid dissociates into and maintains pH inside rbc so carbonic anhydrase can work

Question 40

What increases dissolved oxygen in blood

Answer 40

Increased tidal volume

Question 41

Minute ventilation

Answer 41

Gas entering and leaving lungs
Tidal volume times breathing frequency

Question 42

Alveolar ventilation

Answer 42

Volume of air leaving alveoli
Tidal volume minus dead space times breathing frequency