Brainscape's Knowledge GenomeTM

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


See full index

Systems 1 - The Respiratory System > Pulmonary Flood Flow, Gas Exchange and Transport 2 > Flashcards

Pulmonary Flood Flow, Gas Exchange and Transport 2 Flashcards

1
Q

What volume of oxygen is transported in solution in the plasma?

A

3ml

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

The presence of haemoglobin increases the carrying capacity of oxygen to what value?

A

200ml/L

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

How is the bulk of CO2 carried in the blood?

A

Various forms of solution in plasma and RBC

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

What is the O2 demand of resting tissues?

A

250ml/min

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

What percentage of arterial O2 is extracted by peripheral tissues at rest?

A

25%

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

What form of Haemoglobin makes up 92% of all types found in an RBC?

A

HbA

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

Describe the composition of the 8% of other haemoglobin types

A
  • HbA2 (delta chain replaces beta)

- Glycosylated Hb (HbA1, HbA1b, HbA1c)

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

What factor is the major determinant of the degree to which Hb is saturated with oxygen?

A

Partial pressure of oxygen

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

How long does it take to saturate an Hb molecule with oxygen? How does this compare to its overall exposure time?

A

0.25s to saturate

Overall exposure is 0.75s

Plenty of time

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

List three factors which decrease haemoglobin oxygen affinity

A
  • Decrease in pH
  • Increase in temp.
  • Increase is PCO2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where to the conditions that lead to a decrease in haemoglobin oxygen affinity exist?

A

Locally in actively metabolising tissues (e.g. muscles) which helps to unload oxygen

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

What conditions cause a rise in haemoglobin oxygen affinity?

A
  • Increase in pH
  • Fall in PCO2
  • Drop in temp.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What molecule can cause haemoglobin oxygen affinity to decrease?

A

2, 3-diphosphoglycerate (2, 3-DPG)

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

Where is 2, 3-DPG synthesised?

A

Erythrocytes

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

Where does 2, 3-DPG activity increase?

A

Associated with areas of inadequate oxygen supply e.g heart or lung disease, living at high altitude etc.

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

What is the overall effect of 2, 3-DPG?

A

Helps maintain oxygen release in the tissues

17
Q

What occurs to haemoglobin in the presence of carbon monoxide (CO)?

A

Binds to haemoglobin forming carboxyhemoglobin with an affinity much higher than oxygen

18
Q

What partial pressure of CO is required to cause progressive carboxyhemoglobin formation?

A

0.4mmHg

19
Q

Why is the respiration rate of a person suffering from CO poisoning normal?

A

PaCO2 remains normal

20
Q

What are the five main types of hypoxia?

A 
Hypoxic 
Anaemic 
Ischaemic (stagnant)
Histotoxic 
Metabolic
21
Q

What is the most common type of hypoxia?

A

Hypoxic hypoxia - reduction in oxygen diffusion either due to decreased atmospheric PO2 or tissue pathology

22
Q

What is the cause of anaemic hypoxia?

A

Reduction in O2 carrying capacity due to anaemia

23
Q

What is ischaemic (stagnant) hypoxia?

A

Heart disease results in poor pumping of blood

24
Q

What is histotoxic hypoxia?

A

Poisoning prevents cells using oxygen

25
Q

Give an example of a cause of histotoxic hypoxia

A

CO or cyanide

26
Q

What is metabolic hypoxia?

A

Oxygen delivery to the tissues does not reach increased oxygen demand by cells

27
Q

What proportion of CO2 remains dissolved in plasma and erythrocytes?

A

7%

28
Q

23% of CO2 combines with deoxyhaemoglobin to form what compounds?

A

Carbamino compounds

29
Q

What is the compound which sequesters most of the CO2 excreted by cells?

A

70% converted to carbonic acid

30
Q

Describe the fate of carbonic acid in the blood

A

Dissociates into H+ and bicarbonate ions - the bicarb. is transported into the plasma during the Hamburger Phenomenon to form a buffer and H+ binds to deoxyhaemoglobin to to avoid fucking the pH

31
Q

Why is monitoring plasma [CO2] very important?

A

It is capable of changing the ECF pH

32
Q

What physiological processes monitor plasma [CO2]?

A

Hypo/Hyperventilation

33
Q

How does hypoventilation alter plasma [CO2]?

A

Causes CO2 retardation - plasma [H+] increases - leads to respiratory acidosis

34
Q

How does hyperventilation alter plasma [CO2]?

A

Blows off more CO2, decreases plasma [H+] - leads to respiratory alkalosis

Systems 1 - The Respiratory System (25 decks)

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