8. Gas Exchange and Carriage of Carbon Dioxide in the Blood Flashcards Preview

CRR Respiratory > 8. Gas Exchange and Carriage of Carbon Dioxide in the Blood > Flashcards

Flashcards in 8. Gas Exchange and Carriage of Carbon Dioxide in the Blood Deck (56):
1

Atmospheric pressure

760mmHg

2

% of Nitrogen in atmosphere

79%

3

% of oxygen in atmosphere

21%

4

% of CO2 in atmosphere

0.03%

5

definition of partial pressure

total pressure exerted by each gas

6

how to calculate partial pressure

% of total pressure in the air x total atmospheric pressure

7

where does oxygen diffuse into the blood?

alveoli

8

name of law which explains equilibrium needed for gasses into liquid

Henry's law

9

which 2 factors affect the equilibrium reached for gasses to change into liquid

1. partial pressure of gas
2. solubility coefficient

10

definition for gas conc.

partial pressure x solubility coefficient

11

which is more soluble in water (O2 or CO2) and why?

CO2 as it has a higher solubility coefficient

12

another name for the rapture of the deep

nitrogen narcosis

13

what solubility coefficient does nitrogen have?

very low

14

describe the pressure underwater

increases as you go more deeper

15

what occurs to the pressure of nitrogen when the total pressure increases?

increases considerably

16

effect of increased pressure of nitrogen on the body

increased diffusion of nitrogen into the blood

17

when does decompression sickness occur?

when the diver comes to the surface of the water - rapid changes from high to low pressure

18

what occurs in terms of nitrogen in decompression sickness?

nitrogen gas comes out of the blood

19

what are formed in decompression sickness?

bubbles in the tissues

20

symptoms of decompression sickness

fatigue, joint pain, dizziness, shortness of breath, unconsiousness, paralysis

21

what are the severity of the symptoms of DS dependent on?

the number of bubbles formed

22

treatment for decompression sickness

hyberbaric oxgentaion/ decompression chamber

23

how does a decompression chamber treat decompression sickness?

reduces the size of bubbles formed

24

what occurs during hyperbaric oxygenation?

oxygen partial pressure is increased to 3-4 atmospheres in a chamber- allowing increased diffusion of oxygen into blood

25

what is a gas embolism?

blockage of a blood vessel by a bubble of gas

26

what conditions does hyperbaric oxygenation treat?

- Bacterial diseases
- Carbon monoxide poisoning
- Gas embolisms
- Bone infections
- Smoke inhalation
- Near drowning
- Circulatory problems

27

what 2 specific bacterial diseases does hyperbaric oxygenation treat? and why?

1. gangrene
2. tetanus
as these are anaerobic

28

6 components of the respiratory membrane

alveoli
1. fluid lining alveoli
2. squamous epithelial cells
3. epithelial basement membrane

4. interstitial space

capillary
5. basement membrane endothelium
6. endothelium

29

4 factors affecting diffusion of gases across respiratory membrane

1. thickness of membrane
2. partial pressure difference
3. surface area
4. diffusion coefficient

30

thin membrane. Increase or decreased diffusion?

increase

31

low diffusion coefficient.Increase or decreased diffusion?

decrease

32

large Surface area. Increase or decreased diffusion?

increase

33

bigger difference between partial pressures across the membrane. Increase or decreased diffusion?

increase

34

when can the thickness of the resp membrane increase?

disease

35

diffusion coefficient of oxygen?

1

36

diffusion coefficient of CO2?

20

37

which has a higher PO2? alveoli or alveolar capillary?

alveoli

38

which has a higher PCO2? alveoli or alveolar capillary?

alveolar capillary

39

what can change the pressure of oxygen in alveoli?

increased ventilation

40

what is ventilation?

oxygenated air reaching a certain part of an organ

41

what is perfusion?

deoxygenated blood reaching a certain part of an organ

42

what is V/Q?

the ventilation-perfusion ratio

43

2 factors affecting V/Q

1. ventilation exceeds perfusion
2. perfusion exceeds ventilation

44

what circumstance occurs as a result of heart failure?

ventilation exceeds perfusion

45

what is shunted blood?

blood which is partially oxygenated - not fully saturated

46

what two bloods mix together during a physiological shunt?

deoxygenated blood (general) with deoxygenated blood from the bronchial arteries

47

how much blood pumped from the heart is a result of physiological shunt?

2%

48

at rest, why is the PO2 in the alveoli low?

the lungs are not fully inflated

49

what occurs when the PO2 in the alveoli is low?

decreased diffusion due to smaller difference in partial pressures between membranes. this causes the blood to not be fully saturated with oxygen.

50

what does blood flow in different regions of the lungs depend on?>

exercise

51

where is the VQ ratio higher?

apex of lung

52

when standing, where does most ventilation occur?

apex of lungs

53

when standing, where does most perfusion occur? and why?

the base of the lungs - due to gravity the blood flows downwards

54

what occurs at the base of the lung in terms of PO2?

decreases

55

what occurs at the base of the lung in terms of PCO2?

increases

56

the increases PCO2 and decreased PO2 causes what to happen to the arterioles?

vasoconstriction - which decreases blood flow to this region