Week 1 Flashcards
1
Q
What is the name for the production of blood cells?
A
Haemopoiesis
2
Q
Where are the sites of haemotpoiesis for an embryo?
A
Yolk sac
between 12wks - 28wks
spleen
3
Q
Where are the sites of heamtopoiesis in an adult?
A
axial skeleton i.e
skull
ribs
sternums
pelvis
proximal limbs
4
Q
What is the name for the making of red blood cells?
A
Erythropoiesis
5
Q
What are the cells at each stage of erythropoiesis called?
A
Pronormoblast
Early normoblast
Intermediate Normoblast
Late normoblast
Reticulocyte
Erythrocyte
6
Q
What are the three types of granulocytes?
A
Eosinophils
Basophils
Neutrophils
7
Q
What do neutrophils do?
A
- Short life
- Phagocytose invaders
- Up regulate inflamation
8
Q
What do neutrophils look like?
A
Polymorph segmented nucleus
Neutral staining granules
9
Q
What do eosinophils do?
A
Bi lobed nucleus with orange/red granules
10
Q
What do Eosinophils do?
A
Fight parasites
hypersensitivity
11
Q
what are monocytes?
A
Monocytes live for weeks in the blood and migrate into the tissues to become macrophages
12
Q
Where are bone marrow samples usually taken from?
A
posterior iliiac crest
13
Q
What options are there for taking bone marrow samples?
A
Vaccum aspiration
Core biopsy
14
Q
What are the properites of mature red blood cells?
A
Packe with haemoglobin
No nucleus, mitochondria
Life span = 120days
energy from glycolosis
15
Q
What happens to old red blood cells?
A
Broken down by the spleen
Haem group becomes bilirubin
Iron binds to transferrin and is recycled
Proteins become amino acids and are recycled
16
Q
What hormone regulates erythrocyte production?
A
erythropoietin
17
Q
What stimulates the relase of erythropoietin?
A
Reduced oxygen carrying capacity
18
Q
What are the ratios of plasma, white blood cells , platelets and RBC in blood?
A
55% plasma
54% Erythrocytes
1% white blood cells and platelets
19
Q
What do red blood cells need energy for?
A
maintaining ion balance and cell volume with Na+/K+ ATPase pump
20
Q
What other benefit does making NADH have for red blood cells ( other than the energy)
A
it helps keep iron in its Fe 2+ state
21
Q
What is used by the body to combat oxidative stress?
A
Glutathione
22
Q
Where does glutathione come from?
A
Comes from the hexose monophosphate shunt
an alternative way of metabolising glucose
23
Q
Wha makes up glutothione?
A
Glutamate
Cysteine
glycine
24
Q
What are the three ways CO2 is carried to the lungs?
A
- Dissolved in soloution - 10%
- Bound to Hb - 30%
- As bicarbonate ion HCO3- 60%
25
What enzyme helps CO2 to become the bicarbonate ion?
Carbonic anhydrase
26
What is the structure of the adult haemoglobin?
4 globin protein sub-units each containing a single haem molecule
27
What is the fuction of the haem group?
Each haem group contains on Fe 2+ ion and can bind to one O2 molecule
28
What are the normal haemoglobin conentrations in adults?
130-180 g/L in males
115-165 g/L i females
29
Why can oxygen be transferred from the mothers blood to the foetal blood?
Foetal haemoglobin has a higher affinety for O2 than adults
30
Why can oxygen be transferred from your blood to your muscles?
Myoglobin has a greater affinity for oxygen than CO2
31
Why is it so important that red blood cells have a working ion pump?
As they are stuffed with Hb they have a high osmotic pressure.
They need the pump to stop them bursting
32
What enables red blood cells to have such a weird shape?
The membrane is protein rich so that it is stretchy and cool
33
What pathway regenerates glutathione?
Hexose monophosphate shunt
34
what does anaemia mean?
Reduced total red cell mass
35
What is haematocrit?
Percentages of whole blood that is made up of red bloods cels
36
How is Hb measured?
burst the cells and shine a light through them to see how red they are
37
In what situations are Hb/Hct not very useful for measuring aneamia?
38
What is the bodies response to anaemia?
Increased red cell production
Reticulocytosis
39
What are reticulocytes?
Red cells that have just left the bone marrow
they are big and still have some RNA
40
How long does it take for the up regulation of reticulocyte production in response to aneamia to have an affect?
a few days
41
What is MCV?
Mean cell volume
42
What does low MCV suggest?
Problem with haemoglobinisation
43
What does high MCV suggest?
Problem with maturation
44
What causes microcytic aneamia?
Failed heamaglobin synthesis
45
What is required to make Hb?
Globins
Haem - porphyrin ring and iron
46
What do microcytic aneamic red blood cells look like?
Real small
hypochromic
47
How much iron is absorbed per day?
1mg/day
48
What is important to remember about iron in the body?
Its a closed system
most of the iron is recycled
49
in what forms is iron transferred and stored?
circulating iron is bound to transferrin
iron is stored as ferritin in the liver
50
What is transferrin?
Protein with two binding sites for iron
51
What does transferrin do?
Transports iron from donor tissuses ( intestinal cells) to erythroid marrow
52
What does percentage saturation of transferrin give you information about?
Iron supply
53
What is the most common cause of iron deficency?
Dietry
54
What hand sign indicateds low iron levels
Koilnonychia
55
What is marcocytic anaemia?
Anaemia in which the red cells have a larger than normal volume
56
What does macrocytosis mean?
Large cells and lots of them
57
What is the normal mean corpuscular volume of red blood cells?
80-100 femtolitres
58
What is a megaloblast?
An abnormally large nucleated red cell precursos with an immature nucleus
59
What are the over arching causes of megaloblastic anaemias?
Defects in DNA synthesis and Nuclear maturation
60
What can cause megaloblastic anaemia?
B12 deficiency
Folate deficiency
Rare genetic shit
drugs
61
Why does lack of B12 or Folate cause megaloblastic anaemia?
They are esential for nuclear maturation.
Need them for DNA synthesis
62
What is pernicious anaemia?
Autoimmune condition destorying gastric parietal cells.
Intrinsic factor deficiency an B12 malabsorption
63
Where is folate absorbed ?
In the jejunum
64
How long do your body stores of
Folate
B12
last?
Folate - 4 months
B12- 2-4 yrs
65
Where is B12 absorbed
Ileum
66
What are the excess utilisation causes of folate deficiency?
Haemolysis
Exfoliating dermatitis
Pregnancy
Malignancy
anti convulsant medication
67
What does B12 deficency cause?
Aneamia type symptoms
plus
Neurlogical problems
68
What neurological problems does B12 deficiency cause?
Posterior/dorsal column abnormalities
69
what does pancytopenia?
Low levels of all cells
70
What can you use to measure B12 and Folate?
assay B12 and folate levels in serum
71
How do you treat pernicious anaemia?
life long vitamin B12 injections
72
What are the causes of non-megaloblastic macrocytosis?
Alcohol
Liver disease
Hypothyroidisim
Marrow failure
73
What is spurious macrocytosis?
Size of mature red cell is normal but the MCV is measured as being high
74
What causes spurious macrocytosis?
Increase in reticulocytes
(reticulocytes are bigger)
if blood cells cool and clump together
75
What are haemoglobinopathies?
Hereditary conditions affecting globin chain synthesis
76
Whats the difference between
HbA
HbA2
HbF
HbA - 2 alpha 2 beta
HbA2- 2 alpha 2 delta
HbF- 2 alpha 2 gamma
77
What percentage of each type of heamglobin is found in adults?
HbA - 97%
HbA2 - 2.5%
HbF - 0.5%
78
What is alpha thalassaemia trait?
One faulty alpha chain
Microcytic, hypochromic red cells with mild anaemia
79
What does structural haemoglobin variants mean?
Normal production rate of structurally abnormal globin chains
80
What results from thalassaemia?
Microcytic hypochromic aneamia
81
What chromosome are alpha chains coded on?
Coded on chromosome 16
82
What is barts hydrops fetalis?
No functional alpha genes
83
What is HbH disease?
Severe form of apha thalassaemia
84
What happens in HbH disease?
Only one alpha gene per cell
aneamia with very low MCV and MCH
Also get haemglobins wit 4 beta chains that for tetramers
85
How does HbH disease present?
Moderate aneamia
Splenomegaly
Jaundice
86
Where is HbH disease most common?
S.E asia
Middle east
Mediterranean
87
What are the three classes of beta thalassaemia?
Beta thalassaemia trait
Beta thalassaemia intermedia
Beta thalassaemia major
88
How does beta thalassaemia major persent?
At 6 months of age
Pallor, failure to thrive
Hepatosplenomegaly
Skeletal changes
Organ damage
89
How do you trat beta thalassaemia major?
Regular transfusion program to maintain Hb
This suppresses erythropoiesis of the bad stuff
90
What must you be vary of in people who get regular blood transfussions?
Iron overload
91
How do you treat iron overload?
Iron chelating drugs allow you to pee or poo it out
Desferrioxamine
92
What are the consequences of iron overload?
Endocrcine- growth, diabetes, Osteoporosis
**Cardiac disease**- cardiacmyopathy, arrhythmias
Liver diseasep- cirrhosis, hepatocellular cancer
93
What is sickle trait?
One normal beta gene
one abnormal beta gene
94
What causes sickle cell aneamia?
Two abnormal copies of beta genes
95
What is a sickle crisis?
Episodes of tisse infarction due to vascular occlusion
96
What are the common symptoms of sickle cell anaemia?
Sickle crisis
Chronic haemolysis
Hyposplenism
97
What can precipitate a sickle crisis?
Hypoxia
Dehydration
infection
Cold exposure
Stress/fatigue
98
How do you treat sickle crisis?
Opiate analgease
Hydration
Red cell exchange
99
How do you treat sickle cell aneamia in the long term
Prophylactic pencillin
Folic acid
Hydroxycarbamide
100
What is haemolysis?
Premature red cell destruction
101
What are red cells so suspetable to damage?
Biconconave shape required for ciculation
limited metabolic reserve
cant generate new proteins
102
What is compensated haemolysis?
Increased red cell destruction compensated by increased red cell production
103
What are the physiological consequences of haemolysis?
Erythroif hyperplasia
Excess red cell breakdown products
104
Whats the difference between extravascular and intravascular heamolysis?
Extravascular - reticuloendothelium system (liver/spleen)
Intravascular- red cells destroyed within circulation
105
What are the consequences of intravascular red cell destruction?
Haemoglobinaemia
Methaemalbuminaemia
Haemoglobinuria - pink urine, black on standing
Haemosideriunuria
106
What do spherocytes of blood film suggest
Membrane damage
107
What do red cell fragments on blood film suggest?
Mechanical damage
108
What do heinz bodies on blood films suggest?
Oxidative damage
109
What are the classifications of haemolyisis by site of red cell defect?
Premature destruction - immune or mechanical
Abnormal cell membrane
Abnormal red cell metabolisim
Abnormal haemoglobin
110
What antibiodies cause Autoimmune Haemolysis?
IgG
IgM
111
What can cause red cell membrane defects resulting in haemolysis?
Liver diesease
and
Vitamin E deficiency
112
What is Zieve's Syndrome?
Haeloytic aneamia with alcoholic liver disease
and
Polychromatic macrocytes
113
What are the components that make up haem?
Porphyrin ring + Fe 3+ = Haem
114
What transporters absord iron into the dudodenal enterocyte?
DMT-1
Divalent Metal transporter 1
transports iron into the dudodenal enterocytes
115
What facilitates iron export from the enterocyte to transferrin?
Ferroportin
116
What down regulates ferroportin?
Hepcidin
117
Where is Hepcidin produced and why?
Produced in the liver in response to high iron levels
118
Whats the difference between holotransferrin and apotransferrin?
Holotransferrin is transferrin with iron attatched
apotransferrin is transferrin without iron attatched
119
What are the three compartments looked at in the assesment of iron status?
Functional iron - haemoglobin concentration
Transport iron - Transferrin saturation
Storage iron - serum ferritin
120
What are globin deficiencies called?
Thalassaemias
121
What causes haemochromatosis?
Mutations of the HFE gene
122
How do you treat haemochromatosis?
Weekly venesection
123
Whats the risk of haemchromatosis in first degree relatives
1 in 4
124
What is important to remember about haemochromatosis?
It can be asympotmatic untill ireversible organ damage has occoured
125
