Brainscape's Knowledge GenomeTM

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


See full index

Year 3 - Haematology > Normal Erythropoiesis > Flashcards

Normal Erythropoiesis Flashcards

1
Q

What do RBCs contain to carry oxygen?

A

Haemoglobin - high oncotic pressure, oxygen rich environment (oxidation risk)

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

Do RBCs contain mitochondria?

A

No - limited to glycolysis for energy generation (no Kreb’s cycle)

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

RBCs do not have a nucleus, what does this allow for?

A

Makes it more deformable, and more room for Hb molecules

Can’t divide, can’t replace damaged proteins - limited cell lifespan

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

Why do RBCs have a high surface area / volume ratio?

A

Allow for gas exchange
Need to keep water out

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

Why is it important that RBCs are flexible?

A

To squeeze through capillaries - specialised membrane required that can go wrong

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

Describe the membrane of RBCs

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

Why do RBCs need energy?

A

To maintain specific ion concentrations gradient and keep water out

The sodium potassium pump keeps ion concentrations right
Keeps system working in cell
Keeps water out
But it needs ATP (Energy)

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

Describe the structure of haemoglobin

A

Tetrameric globular protein
HbA (adult) has 2 alpha and 2 beta chains
Heme group is Fe2+ in a flat porphyrin ring
One heme per subgroup
One oxygen molecule binds to one Fe2+ (oxygen does not bind to Fe3+)

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

What is the function of haemoglobin?

A

Deliver oxygen to the tissues
Act as a buffer for H+
CO2 transport

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

Where does red blood cell production occur?

A

In the bone marrow as a result of proliferation and differentiation of HSCs

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

Describe the pathway by which erythropoietin stimulates RBC production

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

Where does red cell destruction occur?

A

In spleen (and liver)

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

What is the average red cell lifespan?

A

120 days

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

Aged red cells are taken up by?

A

Macrophages - taken out of circulation

Red cell contents are recycled

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

Globin chains are recycled to what?

A

Amino acids

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

Heme group is broken down to?

A

Iron and bilirubin

17
Q

Bilirubin is taken to?

A

Liver and conjugated - then excreted in bile (colours faeces and urine)

18
Q

Describe the pathway of breaking down heme to bilirubin

A
19
Q

Oxygen free radicals are easily made as there is a lot of oxygen in blood. Why are free radicals dangerous for RBCs?

A

Free radicals are dangerous
Can oxidise Fe2+ to Fe3+ which doesn’t transport oxygen
Free radicals damage proteins ~(remember we can’t repair/replace proteins as no machinery to do so -so once they’re damaged that’s it)

20
Q

What does a red blood cell need?

A
21
Q

Describe this diagram

A
22
Q

What are examples of reactive oxygen species?

A

Superoxide
Hydrogen peroxide

These are free radicals and have unpaired free electrons

Capable of interacting with other molecules (proteins, DNA) and damaging their structure

23
Q

What is glutathione?

A

Protects us from hydrogen peroxide by reacting with it to form water and an oxidised glutathione product (GSSG) -> maintains redox balance

24
Q

How can glutathione be replenished?

A

By NADPH which in turn is generated by the hexose monophosphate shunt

25
Q

What is the rate limiting enzyme in the process of replenishing glutathione?

A
26
Q

What does the hexose monophosphate shunt produce?

A

Generates NADPH that maintains GSH levels preventing oxidative damage

27
Q

How does CO2 get from tissues to lungs?

A

10% dissolved in solution
30% bound directly to Hb as carbamino-Hb
60% gets there are bicarbonate and the RBC has an important role in generating bicarbonate

28
Q

How many oxygen molecules per Hb?

A

4 O2 molecules

29
Q

What are system requirements for oxygen transport by haemoglobin?

A
30
Q

Describe the oxygen binding curve for Hb

A
31
Q

Describe the oxygen dissociation curve in practice

A
32
Q

HbF has what subunits?

A

2 alpha
2 gamma

33
Q

Why does foetal Hb saturate more PO2?

A
34
Q

Why can small molecules like CO2, H, 2,3 BPG affect oxygen dissociation curve?

A
35
Q

Describe how modulation of saturation at critical low PO2 pressures improve O2 delivery

A
36
Q

What pathway makes 2,3-BPG?

A

Rapapport-Lubering Shunt

37
Q

What can shift the oxygen saturation curve to the right?

A

Molecules that interact with Hb

H+, CO2, 2,3-BPG, Increased temp, Decreased pH

Results in more oxygen delivered to tissues

38
Q

What can shift the oxygen saturation curve to the left?

A

Increased pH (less H+), Decreased DPG, Decreased temp

39
Q

What molecule is increased in chronic anaemia?

A

2,3-BPG (sometimes called DPG)

Year 3 - Haematology (35 decks)

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