Brainscape's Knowledge GenomeTM

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


See full index

Respiratory BJ > 6 Haemoglobin & Gas transport > Flashcards

6 Haemoglobin & Gas transport Flashcards

1
Q

How much Oxygen is dissolved in every litre of plasma?

A

3ml

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

What is the oxygen carrying capacity of the blood?

A

200 ml/L

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

What determines the arterial partial pressure of O2?

A

The oxygen dissolved in the blood

NOT the oxygen carried by haemoglobin

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

What 2 factors influence how much O2 is dissolved?

A
  • Its solubility

- The partial pressure of gaseous oxygen driving the O2 into solution (basically the partial pressure in the alveoli)

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

What is the patial pressure of the oxygen in solution?

A

100mmHg (sometimes called oxygen tension)

Its equal to the PO2 driving it across.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the oxygen demand of resting cells?

A

250ml/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is cardiac output?

A

Around 5L/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How much haemoglobin is in the average person?

A

150g/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How much oxygen is carried in every gram of haemoglobin?

A

1.34ml of O2 per gram of haemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How much oxygen is carried in the haemoglobin of a normal person?
[150g haemoglobin/L]
[5L/min cardiac output]
[1.34ml O2/g of haemoglobin]

A

5 litres every minute
-> 5L x 150g = 750g/min

  1. 34ml O2/g
    - > 750 x 1.34 = 1000ml/min
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How much of the arterial O2 is extracted by tissue at rest?

A

Only about 25%

Since resting tissues use 250ml/min and haemoglobin carries 1000ml/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How is the PO2 gradient maintained betweent the blood & alveoli?

A

Haemoglobin takes up arterial oxygen so the gradient doesnt reach equilibrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the most common form of Haemoglobin? Descibe?

A

HbA
Makes up 92% of haemoglobin
Made up of 2 alpha & 2 beta chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are some other types of haemoglobin?

A

HbA2
HbF (Foetal)
Glycosylated Hb
myoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What makes up foetal haemoglobin?

A

2 Alpha chains

2 Gamma chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What makes up HbA2?

A

2 Alpha chains

2 Delta chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the types of glycosylated Hb?

A

HbA1a
HbA1b
HbA1c

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Where is myoglobin found?

A

In oxidative muscle fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does a foetus extract O2 from maternal blood?

A

HbF has a much higher affinity for O2 than HbA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How do muscles extract O2 from the blood?

A

BY having a higher O2 afinity than HbA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How long is haemoglobin in contact with the alveoli?

A

ARound 0.75 seconds

IT only takes 0.25 to become saturated though.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How far can PAO2 drop before haem saturation goes below 90%?

A

PAO2 can go as low as 60mmHg without losing much arterial oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What factors can affect the affinty of haemoglobin for Oxygen?

A
  • pH
  • PaCO2
  • Temperature
  • [Diphospholycerate]
24
Q

What kind of people produce more diphosphoglycerate?

A

People who live at a high altitude.

Those with heart or lung disease

25
What is the main determinant of haemoglobin saturation?
The PaO2
26
See graphs for how saturation is affected by various factors
In word document and pp
27
What decreases haemoglobin's affinity for oxygen?
Its decreased by: - a pH drop - A PaCO2 increase - A Temp rise
28
What is the physiological benefit of decreasing haemoglobin's affinity for oxygen?
Low pH, high PaCO2 & high temp exist in actively metabolising tissues and decrease haemoglobins affinity for oxygen. This facilitates the dissociation of oxygen from haemoglobin.
29
What increases haemoglobin's affinity for oxygen?
- A pH rise - A PCO2 fall - Temp fall
30
Whats the effect of increased haemoglobin affinity for oxygen?
It makes oxygen unloading more difficult at tissues. | But it makes it easier to collect oxygen in pulmonary circulation.
31
What does 2,3-DPG do?
Decerases haemoglobin oxygen affinity
32
What makes 2.3-DPG?
Erythrocytes
33
Why is 2,3-DPG made in situations with inadequate oxygen?
It helps maintain oxygen release at tissues.
34
Define anaemia?
Any condition where O2 carrying capacity of blood is compromised
35
Give some examples of Anaemic conditions?
- Fe deficiency so cant make enough haem - Haemorrhage, losing blood - Vit B12 deficiency
36
Why is PaO2 normal in anaemia?
Therse no problem with ventilation or gas exchange. Therefore no reduction in the amount dissolved in blood
37
How does anaemia affect the saturation of haemoglobin?
The RBCs would still be fully saturated its just theres less of them
38
What do CO & haemoglobin form?
Carboxyhaemoglobin
39
Describe the affinity of CO for Haemoglobin?
CO has a 250 times greater affinity for haemoglobin than O2 thus preventing transport of oxygen
40
What partial pressure of CO causes carboxyhaemoglobin formation?
0.4mmHg PaCO is all thats needed to cause progressive carboxyhaemoglobin formation
41
What are the symptoms of CO poisoning?
- Hypoxia & Anaemia - Nausea & Headaches - Cherry red skin & Mucous membranes - Potential brain damage & death
42
What is the main thing that drives ventilation?
Getting rid of CO2
43
How many types of hypoxia are there?
5
44
Define hypoxia?
An inadequate supply of oxygen to tissues
45
What is the most common form of hypoxia? describe?
Hypoxic Hypoxia - > Tissue pathology or decreased atmospheric PO2 - > Reduced O2 diffusion at lungs
46
What is the cause of anaemic hypoxia?
Anaemia leads to reduced O2 carrying capacity
47
What is the cause of Ischaemic (stagnant) hypoxia?
Heart Pathology | -> Inefficient blood pumping
48
How does histotoxic Hypoxia occur?
``` Tissue Poisoning (e.g. Hydrogen sulphide or cyanide) -> Cells cant use the oxygen thats delivered to them ```
49
What causes metabolic hypoxia?
Tissue Oxygen demand increases | -> Oxygen delivery to the tissuesdoesnt meet new demands
50
How is CO2 transported in the blood?
- 70%as carbonate in solution - 7% in solution alone - 23% in RBCs as carbamino compounds (Formed with deoxyhaemoglobin)
51
Whats the equation for how CO2 affects ECF pH?
CO2 + H2O ↔ H2CO3 ↔ HCO3 + H+
52
What is carbonate/carbonic acid?
Carbonic acid = H2CO3 | Carbonate = HCO3
53
Why does plasma pH alter during hypo/hyperventilation?
They alter PaCO2, moving the equation and altering [H+]
54
How does hypoventilation affect plasma pH?
Hypoventilation - > CO2 retention - > [H+] increases - > Respiratory acidosis
55
How does hyperventilation affect plasma pH?
Hyperventilation - > Blowin off more CO2 than normal - > [H+] decreases - > Respiratory Alkalosis

Respiratory BJ (31 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions