Brainscape's Knowledge GenomeTM

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


See full index

Year 1 POM > Blood Cell Abnormalities > Flashcards

Blood Cell Abnormalities Flashcards

1
Q

What is anaemia?

A

•Reduction in the amount of haemoglobin in a given volume of blood below what would be expected in comparison with a healthy subject of the same age and gender

  1. By definition, the haemoglobin concentration (Hb) is reduced
  2. The RBC and the Hct/PCV are usually also reduced
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the mechanism of anaemia?

A
  • Reduced production of red cells/haemoglobin in the bone marrow
  • Loss of blood from the body
  • Reduced survival of red cells in the circulation
  • Pooling of red cells in a very large spleen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is an example of a cause and a mechanism?

A

Mechanism: might be reduced synthesis of haemoglobin in bone marrow
Cause: either a condition caused reduced synthesis of haem or one causing reducing synthesis of globin

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

Why use cell size?

A

-Sometimes neither mech or cause obvious so classification is on basis of cells size can help to suggest specific cause
•Microcytic – usually also hypochromic
•Normocytic – usually also normochromic
•Macrocytic – usually also normochromic

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

Describe microcytic anaemia

A

•A microcytic anaemia is one in which average cell size is decreased

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

What are the causes of iron deficiency with increased loss?

A
  • Commonest cause in adults
  • Hookworm commonest cause worldwide
  • Menstrual (menorrhagia)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the causes of iron deficiency with insufficient intake?

A
  • Dietary
  • Vegetarians
  • Malabsorption
  • Coeliac disease (gluten-induced enteropathy)
  • H. pylori gastritis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the causes of iron deficiency with increased requirements?

A
  • Physiological
  • Pregnancy
  • Infancy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the three types of anemia?

A
  1. Microcytic
  2. Normocytic
  3. Macrocytic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the four mechanisms for anemia?

A
  1. Reduced production by the bone marrow
  2. Loss of blood from body
  3. Reduced survival of red cells in circulation
  4. Pooling of red cells in a very large spleen
    - Cells may be normal, large or small
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the different types of polycythaemia?

A
  1. Pseudo (reduced plasma volume can be acute e.g. suddenly water loss or dehydration or chronic e.g. prescribed drug to pass lots of urine or other chronic condition unexplained)
  2. True with an increase in total volume of red cells in circulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are some of the true reasons you might have polychthaemia?

A
  1. Blood doping or over transfusion e.g. blood doping
  2. Appropriately increased erythropoietin e.g. hypoxia
  3. Inappropriate erythropoietin synthesis or use e.g. blood doping or cancer which leads to synthesis of erythropoietin e.g. rumour of kidney which inappropriately secretes erythropoietin
  4. Independent of erythropoietin e.g. intrinsic bone marrow disorder called polychythaemia vera
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why do people get anemia?

A
  • Anaemia is usually due to a reduction of the absolute amount of haemoglobin in the blood stream
  • Occasionally a low Hb results from an increase in plasma volume
  • In a healthy person, anaemia resulting from an increase in plasma volume cannot persist because the excess fluid in the circulation is excreted
  • For practical purposes, anaemia can therefore be regarded as a resulting from a decrease in the absolute amount of haemoglobin in the circulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the common causes of microcytic anaemia?

A
  • Defect in haem synthesis
    •Iron deficiency
    •Anaemia of chronic disease*
  • Defect in globin synthesis (thalassaemia)
    •Defect in α chain synthesis (α thalassaemia)
    •Defect in β chain synthesis (β thalassaemia)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are different types of cells?

A

Small cells: microcytosis (low MCV)
Pale cells: Hypochromia (low MCHC)
Occasional target cells
‘Pencil cells’ (elliptocytes)

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

What is macrocytic anaemia?

A

•A macrocytic anaemia is one in which average cell size is increased

17
Q

Where do microcytic anaemias result from?

A
  1. Macrocytic anaemias usually result from abnormal haemopoiesis so that the red cell precursors continue to synthesize haemoglobin and other cellular proteins but fail to divide normally
    - As a result, the red cells end up larger than normal
  2. Megaloblastic erthpoeisos
18
Q

What is Megaloblastic erthpoeisos?

A
  1. One cause of macrocytic anaemia is megaloblastic erythropoiesis
    - This refers specifically to a delay in maturation of the nucleus while the cytoplasm continues to mature and the cell continues to grow
    - Megaloblasts are generally seen in the bone marrow, not the blood film
19
Q

What is a megaloblast?

A
  • A megaloblast is an abnormal bone marrow erythroblast

* It is larger than normal and shows nucleocytoplasmic dissociation

20
Q

What is megaloblastic anaemia caused by?

A
  • Megaloblastic anaemia is caused by a deficiency of vitamin B12 or folate
  • It is possible to suspect megaloblastic anaemia from the peripheral blood features but to be sure requires bone marrow examination
21
Q

What are common causes of microcytic anemia?

A
  • Lack of vitamin B12 or folic acid (megaloblastic anaemia)
  • Use of drugs interfering with DNA synthesis
  • Liver disease and ethanol toxicity
  • Recent major blood loss with adequate iron stores (reticulocytes increased)
  • Haemolytic anaemia* (reticulocytes increased)
22
Q

What is important to remember about young red cells?

A

Young red cells are about 20% larger than mature red cells so if there is an increased proportion of young red cells (polychromasia/reticulocytes) in the circulation, the average cell size (MCV) will be increased

23
Q

What is the mechanisms of normocytic anaemia?

A

-Recent blood loss: e.g. of causes gasointesitinal haemorrhage, trauma
-Failure of production of red cells e.g. of causes Early stages of iron deficiency
Bone marrow failure or suppression (e.g. chemotherapy)
Bone marrow infiltration (e.g. leukaemia)
-Pooling of red cell in the spleen e.g. of causes Hypersplenism, e.g. liver cirrhosis
Splenic sequestration in sickle cell anaemia

24
Q

What is polycythsemia?

A
  • Polycythaemia literally means ‘many cells’ but it refers specifically to too many red cells in the circulation
  • The Hb, RBC and Hct are all increased compared with normal subjects of the same age and gender
25
Q

What is pseudopolycythsemia?

A

Reduced plasma volume

26
Q

What is truepolycythsemia?

A
  • Increase in total volume of red cells in the circulation
    1. Blood doping or overtransfusion (excessive transfusion and response to hypoxia)
    2. Appropriately increased erythropoietin
    3. Inappropriate erythropoietin synthesis or use
    4. Indepdnet of erythropoietin
27
Q

What can polycythaemia result from?

A
  • Polycythaemia can result from inappropriately increased erythropoiesis that is independent, or largely independent, of erythropoietin
  • This condition is an intrinsic bone marrow disorder called polycythaemia vera
  • It is classified as a myeloproliferative neoplasm
  • Polycythaemia can lead to ‘thick blood’– more technically known as hyperviscosity, which can lead to vascular obstruction
  • Blood can be removed (venesection) to reduce the viscosity
  • Drugs can be given to reduce bone marrow production of red cells
28
Q

What is leukaemia?

A
  • Leukaemia (‘white blood’) is cancer of the blood
  • 5% of all cancers are cancers of the blood
  • In the UK approximately 60 people every day are diagnosed with a cancer of the blood
29
Q

When are blood cancers in common?

A
  • Blood cancers are the most common cancers in men and women aged 15‒24
  • They are the main cause of cancer death in people aged 1‒34 years
  • One in 45 of the UK population will die of leukaemia, lymphoma or myeloma
30
Q

What can Leukaemia result from?

A
  • Leukaemia is actually a bone marrow disease and not all patients have abnormal cells in the blood
  • Leukaemia results from a series of mutations in a single lymphoid or myeloid stem cell
  • These mutations lead the progeny of that cell to show abnormalities in proliferation, differentiation or cell survival leading to steady expansion of the leukaemic clone
31
Q

Why is leukaemia different form other cancer?

A

•Leukaemia is different from other cancer because haemopoietic and lymphoid cells behave differently from other body cells

Year 1 POM (39 decks)

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