Brainscape's Knowledge GenomeTM

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


See full index

Metabolism, Endocrinology and Haematology > Haemopoiesis, Erythropoiesis and Iron (S5L1) > Flashcards

Haemopoiesis, Erythropoiesis and Iron (S5L1) Flashcards

1
Q

What is red bone marrow primarily made of?

A

RBCs, platelets and most WBCs

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

Is red bone marrow found more extensively in adults or children?

A

Children

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

Where is red bone marrow predominantly found in adults?

A

In flat bones such as pelvis, sternum, skull, ribs, vertebrae

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

What is the name of the bone marrow biopsy taken from the left posterior iliac crest?

A

Trephine biopsy

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

What is different about a bone marrow aspirate? (In comparison to trephine)

A
  • Can look at individual cells
  • Liquid
  • Can see the spread of cells in marrow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is haematopoiesis controlled by?

A

Hormones/ cytokines

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

The system that removes RBCs is called…?

A

The Reticuloendothelial System (RES)

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

Give some examples of the cells that are part of the RES

A

Macrophages, kupffer cells, tissue histiocytes, microglial cells in CNS

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

What are the main organs of the RES?

A

Spleen and liver

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

Peripheral Blood Counts? (learn the ranges)

A

Hb: adult male = 130-180 g/L adult female = 115-165 g/L

RBC: adult male = 4.5-6.5 x 10^12/L adult female = 3.9-5.6 x 10^12/L

MCV: 80-100 fL

WBC: 4-11 x 10^9/L

Platelet count: 150-400 x 10^9/L

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

What are the main functions of RBCs?

A
  • Transport O2 and CO2
  • Maintain Hb in its reduced (ferrous) state
  • Generate ATP
  • Maintain osmotic equilibrium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How long do RBCs usually last?

A

120 days

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

Go over Hb structure and O2 dissociation curves

A

Have some MCBG fun

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

Outline haemoglobin catabolism

A

Haemoglobin is broken down by phagocytes into haem and globin.

  • The amino acids of globin can be recycled
  • The iron part of haem can be reused.

The rest of the molecule is converted to bilirubin in liver, bilirubin binds to a sugar, then converted to stercobilin in bile duct where it is excreted in faeces. Some of it is absorbed back into blood and excreted in urine as urobilinogen.

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

An excess of red cell destruction can lead to a build up of bilirubin, which in turn leads to what?

A

Jaundice

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

Erythropoiesis is controlled by what hormone?

A

Erythropoietin (produced in kidney and liver)

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

What is the role of erythropoietin?

A

Stimulates the maturation and release of RBCs from bone marrow

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

Patients who are anaemic often have what deficiency?

A

Iron

19
Q

There is no mechanism for excreting iron. True or false?

A

True

20
Q

How is iron lost?

A

Through hair and skin loss, bleeding

21
Q

Iron is either functional or stored. What are the two stored types called?

A

Ferritin (soluble) and haemosiderin (insoluble)

22
Q

Does most active iron (functional) come from breakdown of RBCs or from gut absorption?

A

Breakdown of RBCs

23
Q

Most of the stored iron in the liver is found in hepatocytes as what type of iron?

A

Ferritin

24
Q

Haemosiderin constitutes 5% of stored iron. It is found mainly in what cell type?

A

Kupffer cells

25
Q

Two forms of iron can be taken through diet (haem and non-haem). Explain both types.

A

Haem - better source of iron, meat, ferrous (Fe2+ form)

Non-haem - cereals, pulses, ferric (Fe3+ form), needs extra reduction step before use

26
Q

Outline the process of iron absorption.

A

1) Fe2+ binds to transferrin
2) Taken into the apical surface of the duodenum and upper jejunum
3) Converted to ferric iron (Fe3+)
4) Either stored as ferritin or reduced to Fe2+ for entry into bloodstream (where it is bound to transferrin)
6) Transported out of cell by ferroportin
5) Either used as Hb or stored in liver

27
Q

Iron is taken into cells (like RBCs) by binding of the iron-transferrin complex to what receptor?

A

Transferrin receptor TfR

28
Q

Absorption of iron is better in what conditions?

A

Acidic

29
Q

What inhibits iron absorption?

A

Tea, chapatis, antacids

30
Q

Dietary iron levels are sensed by what?

A

Villi of enterocytes

31
Q

What is Hepcidin?

A

A negative regulator of iron absorption. It binds to ferroportin, preventing iron getting through, therefore stopping iron absorption.

Macrophages also have ferroportin transporter - so iron can build up inside them (if hepcidin is bound).

32
Q

Iron deficiency is a symptom, but not a…

A

diagnosis. need to find underlying cause

33
Q

Provide some potential reasons for iron deficiency.

A

Insufficient intake/ poor absorption

Increased use due to pregnancy, or pathological: bleeding due to tumour

34
Q

What are the symptoms and signs of anaemia?

A
  • Tiredness
  • Cardiac symptoms (angina, palpitations, heart failure)
  • Reduced oxygen carrying capacity

Signs:

  • Paleness
  • Tachycardia
  • Increased resp. rate
  • Epithelial changes (large tongue, angular stomatitis, spooning of nails)
35
Q

Iron deficiency causes RBCs to be..?

A

Hypochromic (low Hb content so pale in appearance) and microcytic (small RBCs, so low MCV)

36
Q

Serrum ferritin is a commonly used measure of iron status, but what is its drawback?

A

Ferritin is an acute phase protein so is increased with inflammation, malignancy, alcoholism, liver disease. This means that reduced levels indicate iron deficiency, but increased levels do not exclude iron deficiency.

37
Q

NICE recommends what test for iron deficiency?

A

CHR. It remains low during inflammatory response. However, CHR is also low in patients with thalasaemia - cant be used here.

38
Q

Suggest some treatments for iron deficiency.

A

Dietary advice, oral iron supplements, intramuscular injections, intravenous (can be associated with anaphylactic shock), transfusion (only if severe anaemia)

39
Q

Excess of free iron is dangerous. Why?

A

fe2+ can produce radicals - damage lipid membranes, nucleic acids and proteins.

40
Q

What is Haemochromatosis?

A

A disorder of iron excess resulting in end organ damage due to iron deposition.

41
Q

Describe Hereditary Haemochromatosis

A

Recessive mutation in HFE gene. Normally HFE protein competes with transferrin for binding to the transferrin receptor. Mutated HFE cannot bind, so transferrin has no competition. As a result, too much iron enter cell

42
Q

HH is treated with what?

A

Venesection

43
Q

In Transfusion associated haemosiderosis an accumulation of iron can occur. What helps to delay the iron overload?

A

Iron chelating agents (desferrioxamine)

Metabolism, Endocrinology and Haematology (7 decks)

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