Blood

Question 1

Haemolysis

Answer 1

Breaking down of RBCs
Occurs due to incompatibility of blood type
RBCs block vessels and cause tissues to become hypoxic
In extreme cases, we get lysis of RBC and haemoglobin released into the blood
The iron in haemoglobin is extremely toxic to kidney cells
Other symptoms include: hypotension, kidney failure, DIC (bleeding)

Question 2

Haemolytic syndrome in foetus/new born

Answer 2

1st pregnancy - Protected by the placenta-blood barrier, the mother is not exposed to Rh agglutinogens until the time of childbirth due to placental tearing
2nd pregnancy:
Antibodies cross placental barrier
Born with severe anaemia
Treatment: use anti-Rh γ globulin to mask Rh agglutinogens

Question 3

4 diseases of blood plasma

Answer 3

Bleeding
Thrombosis
Hereditary angioedema
Complement deficiency

Question 4

7 diseases of blood cells

Answer 4

Haematological malignancies
Sickle cell anaemia
Thalassaemia
Haemoglobinopathies
Leukopenia - decreased number of leukocytes 
Thrombocytopenia - low platelet count
Infectious mononucleosis

Question 5

Anaemia

Answer 5

Decreased number of RBCs

Question 6

Leukopenia

Answer 6

Decreased number of WBCs

Question 7

Thrombocytopenia

Answer 7

Decreased number of platelets

Question 8

Erythrocytosis

Answer 8

Increased number of RBCs

Question 9

Leukocytosis

Answer 9

Increased number of RBCs

Question 10

Thrombocytosis

Answer 10

Increased number of platelets

Question 11

Causes of bleeding

Answer 11

Injury (acute)
Disease (chronic) - bleeding internally
Low platelet counts (thrombocytopenia - mild)
Coagulation deficiencies (haemophilia - severe)
Vitamin K deficiency
Drugs
Liver disease (although may also cause thrombosis)
Infection/sepsis: disseminated intravascular coagulation
Aneurysm rupture

Question 12

Causes of thrombosis

Answer 12

Atheroscelerosis - deposition of lipids in areas of the arterial wall
Cancer
Immobilisation
Surgery
Hypercoagulability
Thrombocythaemia (high platelets level) - pooling of blood in lower extremities

Question 13

Leukaemia

Answer 13

Accumulation of white blood cells in the bone marrow and blood
Bone marrow failure
Decreased RBCs and platelets
Increased WBCs in blood or in advanced disease, decreased white cells (due to BM failure)
Blood hyper viscosity due to increased WBCs causing respiratory or neurological symptoms
Infection if decreased WBC
Tiredness/anaemia
Bleeding

Question 14

Lymphoma

Answer 14

Affects lymph nodes
T or B lymphocyte neoplasia
Non-Hodgkin or Hodgkin
Hodgkin Lymphoma characterised by Reed-Sternberg cells
Reed-Sternberg cells generally originate from B lymphocytes, which become enlarged and are multinucleate or have a bilobed nucleus

Question 15

Microcytic anaemia

Answer 15

Pale and small RBCs due to reduced haemoglobin production

Question 16

Cause of sickle cell disease

Answer 16

Mutation in the Hb b globin gene Glu 6→Val
Polymerisation of Hb, distorting RBC
Widespread in Africa (Carribean), Middle East, India and Med
Sickle caused because proteins folds incorrectly

Question 17

Effect of sickle cell disease

Answer 17

“Sickling” of RBC (particularly in homozygous disease)
Sickle cell crisis due to blockage of microvasculature
Heterozygosity confers protection against malaria
Homozygous anaemia is extremely dehabilitating

Question 18

How do we react to vascular trauma?

Answer 18

Vasoconstriction, reduction of blood flow to the area
Platelet activation and adhesion to collagen
Platelet shape change
Granule release - increased local concentrations of:
Platelet activators
Coagulation factors
Vasoconstrictors
Acts to amplify the haemostatic pressure
Primary plug formed and blood loss stopped

Question 19

Explain secondary haemostasis - consolidation of the haemostatic plug

4 steps

Answer 19

1. FVII from the blood binds to TF expressed on the membrane of cells surrounding the blood vessel
2. Activated FVII next proteolytically cleaves and activates FX
3. FXa then converts prothrombin to thrombin
4. thrombin converts fibrinogen to fibrin

Question 20

6 triggers for induced bleeding

Answer 20

Trauma
Surgery
Sepsis
Aneurysm rupture 
Drugs (anticoagulants, aspirin)
Vitamin K deficiency (mild to severe)

Question 21

Vitamin K deficiency

Answer 21

Malnutrition
Fat malabsorption
Liver disease (alcoholic cirrhosis)
May occur in newborns (vitamin K injection/tablets for newborns)
Due to Vitamin K Antagonists (VKA: warfarin, acenocoumarol) over-dosage
Associated with (severe) bleeding - Can be reversed by vitamin K administration

Question 22

Immune thrombocytopenic purpura (ITP)

Answer 22

produces antibodies against their platelets so theres never a high enough platelet count

Question 23

2 inherited defects in platelet-vessel wall interaction

Answer 23

Von Willebrand syndrome.

Bernard–Soulier syndrome.

Question 24

2 inherited in platelet - platelet interaction

Answer 24

Glanzmann thrombasthenia.
Congenital afibrinogenemia.
Platelets don’t stick together so no plug

Question 25

Wiskott-Aldrich syndrome

Answer 25

Defects in platelet granules, secretion and signal transduction

Question 26

Haemophillia A

Answer 26

F VIII

Question 27

Haemophilia B

Answer 27

F IV

Question 28

Thrombosis

Answer 28

Involves the formation of a clot inside the vessel, blocking blood circulation
This causes ischaemia (tissue death), malfunction, pain or swelling in the organ or tissue affected.

Question 29

Hypercoagulability

Answer 29

Increased tendency to have thrombosis

Question 30

Stasis

Answer 30

Lack of movement of the blood causing pooling

Question 31

Trigger for arterial thrombosis

Answer 31

Rupture of the atherosclerotic plaque

Question 32

Two types of arterial thrombi

Answer 32

1. Mural thrombi

2. Occlusive thrombi

Question 33

DVT and PE

Answer 33

A blood clot that forms in a vein deep in the body usually in the legs
If a part of the blood clot breaks free (called an embolism) it can become lodged in the blood vessels of the lung, causing pulmonary embolism