Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Haematology > Red Cells > Flashcards

Red Cells Flashcards

1
Q

What substances are required for red cell production?

A

Metals - iron, copper, cobalt, manganese.
Vitamins - B12, Folic acid, thiamine, B6, C, E.
Amino acids
Hormones - Erythropoitin, GM-CSF, androgens, thyroxine.

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

Where does red cell breakdown occur?

A

Reticuloendothelial system.

Macrophages in spleen, liver, lymph nodes and lungs.

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

What is the normal lifespan of a RBC?

A

120 days

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

What are the products of RBC breakdown?

A

Globin - amino acids reutilised.
Haem - Iron recycled into haemoglobin. Haem - biliverdin - bilirubin.

Unconjugated bilirubin is then bound to albumin in plasma.

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

Where can genetic defects occur in congenital anaemias?

A

In red cell membrane
In red cell metabolic pathways
In haemoglobin.

Most result in haemolysis.

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

What is responsible for maintaining a red cell’s shape?

A

Skeletal proteins maintain shape and deformability.

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

What is Hereditary Spherocytosis?

A

Autosomal dominant normally.
Defect in 5 different structural proteins: Ankyrin, Alpha spectrin, beta spectrin, band 3, Protein 4.2.

Results in spherical red cells that are then removed a bit faster from the circulation by reticuloendothelial system.

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

What is the clinical presentation of Hereditary Spherocytosis?

A

Variable due to which proteins are affected.
Anaemia - due to fast breakdown
Jaundice (neonatal) - faster breakdown so more bilirubin.
Splenomegaly
Pigment gallstones

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

What is the treatment for Hereditary Spherocytosis?

A

Folic acid
Transfusion
Splenectomy if anaemia severe.

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

What are some other examples of membrane disorders?

A

Hereditary Elliptocytosis
Hereditary Pyropoikilocytosis (all different shapes and sizes)
South East Asian Ovalcytosis.

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

What is anaemia?

A

Reduction in red cells or their haemoglobin content.

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

Where is Erythropoietin made?

A

Kidneys

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

What are the 2 important enzyme pathways in RBCs?

A

Glycolysis to provide energy - G6PD. Pyruvate kinase

Pentose phosphate shunt to protect from oxidative damage. Glucose 6-phosphate dehydrogenase.

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

What is the function of Glucose 6 Phosphate Dehydrogenase?

A

Protects red cell proteins from oxidative damage:

  • produces NADPH vital for reduction of glutathione.
  • reduced glutathione scavenges and detoxifies reactive oxygen species.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is G6PD Deficiency?

A

Commonest disease causing enzymopathy. Red cells become vulnerable to oxidative damage - blister and but shaped cells.
Most common in malarial areas and is X- linked so female carriers and affected males.

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

What is the clinical presentation of G6PD deficiency?

A

Anaemia
Neonatal jaundice
splenomegaly
Pigment gallstones.

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

What are some external factors that precipitate haemolysis in G6PD deficiency?

A

Drugs
Broad beans
infection

Results in intravascular haemolysis and haemoglobinuria - vessels burst resulting in free floating haem.

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

What is another example of an enzyme deficiency?

A

Pyruvate kinase deficiency.
Results in reduced ATP, increased 2,3-DPG and rigid cells.

Presents with variable severity of anaemia, jaundice, gallstones.
Rare.

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

What is the structure of an adult haemoglobin molecule?

A

4 molecules of haem
2 alpha chains
2 beta chains
Iron is found within the haem molecule.

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

How does haemoglobin take in and release oxygen?

A

Haemoglobin has a relaxed binding structure when oxygen is bound. Once 1 molecule is bound it is easier for others to bind - cooperation.
Undergoes conformational change to release oxygen resulting in a tight binding structure. 2,3-DPG stabilises this tight structure.

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

What are the different types of haemoglobin?

A

Adult (HbA) is 2 alpha chains and 2 beta chains.
Foetal (HbF) is 2 alpha and 2 gamma chains. has a higher affinity for oxygen.
HbA2 is 2 alpha and 2 delta chains - only small amount of this.

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

How is your haemoglobin affected by your parents genes?

A

Get 2 alpha genes from both mum and dad located in Chr16.

Get 1 beta gene from mum and dad located in Chr11.

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

What is Thalassaemia?

A

Reduced or absent globing chain production. Can be alpha, beta, gamma or delta.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What sort of inheritance do most haemoglobinopathies have?

A

Autosomal recessive

Usually carriers are asymptomatic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is Sickle cell disease?
Point mutation in beta gene which if get 2 copies leads to polymerisation of haemoglobin forming crystals that are irreversibly stuck together - causes sickle shape. Oxygen transfer is okay as sickle haem has allowed affinity for oxygen.
26
What are the consequences of polymerisation in sickle cell disease?
Haemolysis which leads to endothelial activation, promotion of inflammation, coagulation activation, deregulation of vasomotor tone by vasodilator mediators leading to Vaso-occlusion.
27
How does sickle cell disease present?
``` Can affect whole body. Severe bone pain Stroke Pulmonary infarcts Increased infection risk Hyposplenism Chronic haemolytic anaemia Gallstones Aplastic crisis Sequestration crisis - liver and spleen. ```
28
How should severe bone pain be treated?
``` Analgesia within 30mins Opiates if needed Hydration Oxygen Antibiotics ``` Adults tend to be in long bones, children in small bones. Triggered by stress on body.
29
What is the management for sickle cell disease?
Life long prophylaxis: - vaccination - penicillin - malarial - folic acid Acute events: - hydration - oxygen - prompt treatment of infection - analgesia (opiates, NSAIDs) - Blood transfusion (need to be wary of iron overload and alloimmunisation). Disease modifying drugs: Hydroxycarbamide Bone marrow transplantation Gene therapy.
30
What is meant by alpha+?
Only receive 1 alpha gene from 1 parent but 2 from the other. -a/aa
31
What is meant by alpha 0?
Receive no alpha genes from 1 parent but 2 from another. | --/aa
32
What occurs as a result of chain imbalance in thalassaemia?
Chronic haemolysis and anaemia.
33
What is homozygous alpha 0 thalassaemia?
No alpha chains at all | Hydrops fetalis occurs which is incompatible with life.
34
What is beat thalassaemia major?
Homozygous beta thalassaemia. No beta chains at all. Can still produce foetal chains but once they start switching will need life long transfusion due to anaemia.
35
What is thalassaemia minor?
Carrier state Hypochromic microcytic red cell indices. Asymptomatic usually.
36
How does beta thalassaemia major present?
``` Severe anaemia Present 3-6months expansion of ineffective bone marrow Bony deformities Splenomegaly Growth retardation ``` Life expectancy <10years.
37
What is the treatment for beta thalassaemia major?
Chronic tranfusion support 4-6weeks. Normal growth and development due to this but iron overloading. Needs to be treated or death due to liver, heart, endocrine failure.
38
How is iron overload treated?
Iron chelation therapy - s/c desferrioxamine infusions or oral deferasirox. Chelation allows iron to be bound and then excreted from body. Improve life expectancy to almost normal but required regular ferritin and MRI scan monitoring.
39
What are some rare defects in haem synthesis?
Sideroblastic anaemia - defects in mitochondrial steps. | Porphyrias - defect in cytoplasmic steps
40
What are the normal ranges of haemoglobin?
Male 12-70yrs (140-180g/L) Male >70yrs (116-156g/L) Female 12-70yrs (120-160g/L) Female >70yrs (108-143g/L)
41
What are the clinical features of anaemia?
``` Features due to reduced oxygen delivery to tissues. Tiredness Pallor Breathlessness Swelling of ankle Dizziness Chest pain ``` Depend on age, speed of onset and Hb level. ``` Evidence of bleeding Symptoms of malabsorption - diarrhoea, weight loss. Jaundice Splenomegaly Lymphadenopathy ```
42
What are some problems that occur in bone marrow that may cause anaemia?
Cellularity Stroma Nutrient deficiency
43
What are some problems that occur within red cells that cause anaemia?
Membrane Haemoglobin Enzymes
44
What are some causes of destruction loss that may result in anaemia?
Blood loss Haemolysis Hypersplenism
45
What is MCH?
Mean cell haemoglobin | Tells us about colour of cells (how much haemoglobin)
46
What is MCV?
Mean Cell Volume | Tells us about red cell size
47
What are the different morphological types of RBC?
Hypochromic microcytic - small pale cells. Normochromic normocytic - normal cells of normal size. Macrocytic - big cells that are not full with haemoglobin, flabby and useless.
48
What further tests would you do if red cells were hypochromic microcytic?
Serum ferritin - test of iron stores. | Iron deficiency is commonest cause of hypochromic microcytic cells.
49
What further test would you do if red cells were normochromic normacytic?
Reticulocyte count | Tells you if bone marrow is working properly (50-100 is normal range).
50
What further test would you do if red cells were macrocytic?
B12/folate | Bone marrow
51
What can you tell form serum ferritin results?
Low - iron deficiency anaemia. Normal/Increased - thalassaemia or secondary anaemia.
52
What is secondary anaemia?
Iron levels are normal but there is an inability to use stores efficiently. Anaemia of chronic disease. Ferritin often elevated.
53
What is the route of iron metabolism?
Absorbed iron bound to mucosal ferritin and sloughed off or transported across the basement membrane by ferroportin. Becomes bound to transferritin in the plasma. Stored in the liver as ferritin. No pathway for excretion of excess iron.
54
What is the role of Hepcidin?
Blocks ferroportin so reduces intestinal iron absorption and mobilisation of reticuloendothelial cells. Synthesised in hepatocytes in response to increasing iron levels and inflammation.
55
What are some clinical signs of iron deficiency?
``` Hypochromic microcytic cells Koilonychia Angular cheilitis Atrophic tongue Gastric ulcers Gastritis Carcinoma of colon ```
56
What is the management for iron deficiency?
Oral iron, IV if needed. Blood transfusion if severe Correct the cause - diet, ulcer therapy, gynaecologist interventions, surgery.
57
What can you tell from reticulocyte count?
Increased - Acute blood loss, haemolysis. Normal/Low - Secondary anaemia, hypolasia, Marrow infiltration.
58
What is haemolytic anaemia?
Accelerated red cell destruction that is compensated for by bone marrow. Haemolysis can be extravascular (in tissues) and intravascular (within vessels). Can be congenital or acquired.
59
What are the different types of acquired haemolytic anaemia?
Immune - mostly extravascular. Non-immune - most intravascular.
60
What is Direct Anti-globulin Test?
Detects antibody or complement on red cell membranes. Reagent contains either anti-human IgG or anti-complement. Binds to antibody and causes agglutination - implying immune basis of haemolysis. Also called Coombs test.
61
What are the different possibilities of antibodies if the DAGT test suggests immune haemolysis?
Warm autoantibody - autoimmune, drugs, CLL. Cold autoantibody - CHAD, Infections, Lymphoma. Alloantibody - Transfusion reaction.
62
What is the management for haemolytic anaemia?
Folic acid to support marrow function. Correct cause - immunosuppression if autoimmune e.g. steroids, treat trigger. Remove site of red cell destruction - splenomegaly. Treat sepsis, leaky prosthetic valve etc. Consider transfusion
63
What test would you carry out for macrocytic anaemia?
B12/folate assay | Blood film/bone marrow.
64
What could be the cause of different B12/folate results?
Megaloblastic - B12 deficiency, folate deficiency. Non-megalobalstic - Myelodysplasia, marrow infiltration, drugs.
65
How is vitamin B12 absorbed?
Dietary b12 binds to intrinsic factor, secreted by gastric parietal cells. B12-IF complex attaches to specific IF receptors in distal ileum. Vitamin B12 bound by trans cobalamin II in portal circulation for transport to marrow and the tissues.
66
What are some causes of B12 deficiency?
Pernicious anaemia | Gastric/ileal disease
67
What are some causes of Folate deficiency?
Dietary increased requirements GI pathology
68
What is pernicious anaemia?
Autoimmune disease where there are antibodies produced against intrinsic factor and gastric parietal cells. There is malabsorption of dietary B12. Symptoms take 1-2 years to develop.
69
What is the treatment for Megaloblastic anaemia?
Replace depleted vitamin B12 - I/m injection - 3monthly maintenance. Oral folate replacement.

Haematology (6 decks)

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