Brainscape's Knowledge GenomeTM

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


See full index

Year 3 Immunology > 6. Red Cells > Flashcards

6. Red Cells Flashcards

1
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
2
Q

What causes anaemia?

A

Blood loss
Increased destruction
Lack of production
Defective production

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

How are red cells produced?

A

Come from hemopoetic stem cell
Develop into proerthybolsast
Then early and late erythroblasts
Finally normoblasts and reticulocyte and erthyrocyte

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

What do you need for red cell production

A

Iron, cobalt, manganese
Vitamins B12, folic acid, thiamine, Vit B6, C, E
Amino acids
Erythropoietin, GM-CSF, androgens, thyroxine

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

How do red cells breakdown?

A 
Normal red cell lasts for 120 days
It is recycled 
Globin—> utilised
Iron—> recycled into heamoglobin
Haem—> bilirubin gives colour to bile. Bound to albumin in the plasma and becomes unconjugated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What shape is a red blood cell?

A

Bi concave, depression in middle

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

What is a red cell?

A

Membrane
Enzymes
Haemoglobin

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

What happens if you have a genetic condition and make a rubbish red blood cell?

A

Heamolysis, don’t last as long and are killed

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

Describe the structure of the red blood cell membrane

A

Phosphate bi-lipid layer plus proteins
Spectrin and Ankrin link cells to floor
Defects in skeletal proteins lead to abnormalities

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

What is the most common red cell membrane deformity

A

Hereditary spherocytosis
Most common forms autosomal dominant
Defects in 5 different structural proteins:

Ankyrin
Alpha spectrin
Beta Spectrin
Band 3
Protein 4.2
Red cells become spherical. Removed from circulation by the reticuloendothelial system (spleen, liver, bone marrow)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the clinical presentation of hereditary spherocytosis?

A 
Anaemia
Jaundice
Splenomegaly
Pigment gallstones
Potential increased bilirubin

(Very common presentation with anyone with haemolytic anaemia)

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

What is the treatment of heriditary spherocytosis?

A

Folic acid
Blood transfusions (if red cell breakdown is very fast)
Splenectomy is severe anaemia

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

What are other rare membrane disorders?

A

Hereditary elliptocytsosis- cells form eliptocytes instead of spheres due to different proteins affected.
Hereditary pyropoikilocytosis- red cells look like they’re on fire
South East Asian ovalocytosis- benign

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

What are the two main enzyme pathways of the red blood cells?

A

Embden meyerhof glycolysis pathway- glycolysis pathway. Two important enzymes are glucose 6 phosphatase dehydrogenase. Protects the cell against oxidative damage

Pyruvate kinase is the other one

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

What is G6PD?

A

Commonest disease causing enzymolathy in the world. Many genetic variants. Cells vulnerable to oxidative damage

Confers protection against malaria
X linked- affects males, female carriers

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

What is the clinical presentation of GD6P

A 
Bite and blister cells
Variable degrees of anaemia
Neonatal jaundice
Splenomegaly
Pigment gallstones

Can be precipitated by drugs, broad beans, infection.
Leads to intravaculae haemolysis
Heamoglobinuria - heamoglobin in urine

17
Q

What is PKA deficiency?

A

Pyruvate kinase deficiency which leads to reduced ATP, rigid cells. Clinically this leads to various types

Anaemia
Jaundice
Gallstones

18
Q

What is haemoglobin?

A

Heam” (iron) molecules surrounded by four globin chains- 2 alpha and 2 beta chains

Binds oxygen and release it throughout the body.

Gives you oxygen when you need oxygen. Oxygen dissociation curve shifts to the right in high demand oxygen situations.

19
Q

How do you inherit the chains of heamoglobin?

A

2 alpha chains from mother
2 alpha chains from dad
1 beta chain from dad
1 beta chain from mum

Also possess suppressed levels of heamoglobin A2 and fetal heamoglobin

20
Q

What are heamoglobinopathies?

A

Inherited abnormalities of haemoglobin synthesis

Reduced or absent globin chain production- thalassaemia- alpha or beta, produced normal chains but less of them

Point mutations leading to abnormal globin chains- sickle cell disease. Point mutation that leads to abnormal globin

21
Q

People who have heamoglobinopathies are less likely to have malaria, does this apply to people who are only carriers?

A

Yes

22
Q

What is sickle cell anaemia?

A

Haemoglobin forms crystals in low oxygen situations within the red blood cells and they “sickle”

This leads to haemolysis. This leads to inflammations, coagulation, endothelial damage, vasospamsm and in the end vaso-occlusion

23
Q

How does sickle cell disease present?

A

Stroke- screen with cranial Doppler
Pulmonary infarcts
Cardiomegaly
Bone marrow hyperplasia (very common, present with crisis)
Renal impairment
Increased risk of gallstones
Sickling in spleen- auto infarction of the spleen.
Aplastic crisis- infection with erythrovirus causing no formation of RBC, leads to severe anaemia and requires transfusions

24
Q

What is a sickle cell crisis?

A

Severe bone pain requiring opiods to treat. Keep hydrated and oxygenated

Children present in peripheries
Old people present in back, hips, axial bones

Triggered by infection, stress on the body

25
Q

How do you manage sickle cell disease

A

Vaccination
Penicillin
Folic acid

Chronic blood transfusion blood transfusion or bone marrow for particular difficult disease

Disease modifying drug- hydroxycarbimide, prevents haemoglobin from sickling

26
Q

What is thalassaemia?

A

Reduced or absent chain production.

Can be alpha thalassaemia- reduced alpha chain causes anemia, no alpha chains aren’t compatable with life

Beta thalassaemia- is always compatible with life, causes anaemia and haemolysis. Severe disease leads to transfusion dependent anaemia

27
Q

What is thalassaemia minor?

A

Reduced red cell size as they’re a carrier of thalassaemia. Doesn’t effect life.

28
Q

What occurs in beta thalassaemia major

A 
Severe anaemia at 3-6 moths of age
Expansion of ineffective bone marrow (hair on end appearance)
Bony deformities
Splenomegaly
Growth retardation
29
Q

How do you treat beta thalassaemia major?

A

Chronic transfusion support
Normal growth and development
Iron overloading- death in 2nd or 3rd decades to to heart/ liver/ endocrine disorders. Treated with iron chelation.

30
Q

What is iron chelation?

A 
Giving drugs desfererrioxamine infusions (desferal)
Oral deferasirox (exjade)

Good adherence to chelation makes life expectancy near normal for those who suffers with beta thalassaemia. They must have regular ferritin monitoring and MRI scans

31
Q

What are the rare gene defect in haem synthesis?

A

ALA synthesise mutations
Hereditary
Acquired

Year 3 Immunology (26 decks)

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