Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

human physiology and exercise > diffusion of gases > Flashcards

diffusion of gases Flashcards

1
Q

what is Dalton’s law?

A
  • the pressure of a gas is equal to the sum of the pressures of the indivual gases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the atmospheric pressure?

A
  • 760mmHg
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the percentage and partial pressure of nitrogen?

A
  • 78.1%
  • 594mmHg
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the percentage and partial pressure of oxygen?

A
  • 20.9 %
  • 159mmHg
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the percentage and partial pressure of carbon dioxide?

A
  • 0.037%
  • 0.25mmHg
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

does percentage or partial pressure remain the same?

A
  • percentage always remains the same whereas partial pressure can change
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

describe air in the lungs in relation to water vapour

A
  • fully saturated with water vapour (100% humidity)
  • partial pressure of 46mmHg
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

describe the thickness of the diffusion barrier

A
  • 2 cell thick
  • 0.1-1.5 um
  • alveolar wall and vascular wall
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

describe passage of oxygen once it enters the alveoli

A
  • enters alveoli> dissolves in surfactant> crosses alveoli epithelium> fused basement membranes> vascular endothelium> attach to haemoglobin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is fick’s law of diffusion?

A

rate of diffusion proportional to (area/ thickness) x (P1-P2) x solubility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how does pressure difference and solubility affect the speed of diffusion?

A
  • greater pressure difference, the faster
  • greater the solubility, the faster
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

does 02 or C02 diffuse quicker?

A
  • C02 diffuses quicker as it is more soluble
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the gas partial pressure in solution?

A
  • gas and liquid molecules move between air and liquid to achieve equilibrium of PP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what does movement of molecules depend on? (three things)

A
  • temperature
  • pressure difference
  • solubility
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

why is the rate of diffusion important- why does it need to be fast enough?

A
  • fast enough so that gases in alveoli and blood equilibrate during passage of blood across an alveolus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

when is equilibrium at rest complete? compared to exercise?

A
  • complete at 1/3 of the time blood spends near alveolar air
  • less time during exercise
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what can diffusion rate affect and limit?

A
  • affects arterial 02 content
  • limits functional capacity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is emphysema?

A
  • limited surface area and poor elastic recoil
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is fibrotic lung disease?

A
  • thick barrier and less lung compliance (expandability)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is pulmonary oedema caused by?

A
  • pressure changes in capillaries
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is asthma?

A
  • poor ventilation due to constricted airways
22
Q

what is the law of mass action?

A
  • when a reaction is at equilibrium, the ratio of substrates and products will remain constant
23
Q

what is the rate of forward and backward reaction at equilibrium?

A
  • reactions are the same
24
Q

what happens if equilibrium is disturbed?

A
  • rate changes
25
Q

why is dissolved oxygen not enough? compare this to resting rate of 02 consumption

A
  • around 3ml/l so could only supply tissues with 15ml/ min at a cardiac output of 5l/min
  • 02 consumption is 250ml/ min
26
Q

what is oxygen carried by?

A
  • haemoglobin; forms oxyhaemoglobin
  • contains 4 globin’s and 4 haem groups
27
Q

what is haemoglobin?

A
  • oxygen binding protein contained within red blood cells
28
Q

what do the haem groups contain?

A
  • ferrous atom in centre of each haem (02 binds to Fe2+ )
29
Q

how does haemoglobin establish pp02 difference between blood and alveoli?

A
  • acts to steal oxygen from blood to create a gradient
  • only stops when fully saturated
30
Q

does 02 bound to haemoglobin influence partial pressure?

A
  • it doesn’t contribute to the PP as it maintains a pressure difference causing more oxygen to diffuse across
31
Q

how much oxygen is carried around?

A
  • 200ml02l/ blood
32
Q

what is anaemia- how much oxygen would be carried around?

A
  • lack of red blood cells
  • would only carry 121ml 02l/min
33
Q

what are the two factors that determine how much oxygen is carried?

A
  • partial pressure of 02 driving 02 into the blood
  • amount of haemoglobin in the blood
34
Q

what is the oxyhaemoglobin dissociation curve?

A
  • describes relationship between partial pressure of oxygen and saturation of haemoglobin
35
Q

what is the shape of the dissociation curve- explain

A
  • sigmoid shape
  • flat part at high partial pressure and steep part at low partial pressure
  • saturation drops at higher altitude
36
Q

what happens to the release of oxygen in tissues at different pp02?

A
  • sensitive at low pp02 (off-loading)
  • 02 not affected at high pp02(loading)
37
Q

what does a shift to the left mean?

A
  • increased saturation for given pp02
  • improved loading but prevents unloading
38
Q

what does a shift to the right mean?

A
  • less saturation for given pp02
  • known as bohr shift
  • unloads easily but hard to load
39
Q

what three factors affect 02 binding to haemoglobin?

A
  • activity
  • effect of DPG
  • temperature
  • volume of C02/ pH
40
Q

how does activity affect 02 binding to haemoglobin?

A
  • low pH causes a right shift
  • high pH causes a left shift
41
Q

how does diphosphoglycerate affect 02 binding to haemoglobin?

A
  • added DPG causes a right shift
  • no DPG causes a left shift
42
Q

how does temperature affect 02 binding to Hb?

A
  • high temperature causes right shift
  • low temperature causes left shift
43
Q

how much C02 is dissolved in plasma and why?

A
  • around 27ml/L (7 %)
  • as more soluble so more dissolved
44
Q

how else is C02 carried in blood?

A
  • 70% of C02 carried in form of bicarbonate ions
45
Q

what is the equation for bicarbonate ions?

A

C02 + H20 > H2C03 > H+ + HC03-

46
Q

what enzyme works to convert carbon dioxide and water into carbonic acid?

A
  • carbonic anhydrase
47
Q

how much C02 is bound to Hb?

A
  • 23% bound
  • Hb + C02 = carbaminohaemoglobin
48
Q

what is the relationship between H+ ions and haemoglobin?

A
  • haemoglobin binds the H+ ions that are released from reaction of C02 + H20
49
Q

what does Hb binding the H+ ions prevent?

A
  • acidosis = to much acid in bodily fluids
50
Q

what does more carbon dioxide result in?

A
  • more hydrogen ions
  • more acidic

human physiology and exercise (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions