Brainscape's Knowledge GenomeTM

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


See full index

MEH > Session 5 > Flashcards

Session 5 Flashcards

1
Q

Where are RBCs, platelets and most WBCs produced in the body?

A

Bone marrow

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

Describe the arrangement of bone marrow in the skeleton of infants and adults

A

Extensive throughout the skeleton in infants

Active marrow more centrally located and less extensive in adults

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

Give three examples of more centrally located areas of marrow in adults

A 
Pelvis 
Sternum 
Skull 
Ribs 
Vertebrae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Name two methods of testing bone marrow

A

Trephine biopsy

Bone marrow aspirate

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

How is a trephine biopsy carried out?

A

Bone marrow is removed from the posterior left iliac crest

Marrow fixed and stained to see if there is enough of all cell lines/architecture

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

In a trephine biopsy bone marrow is removed from..

A

The posterior left iliac crest

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

How does a bone marrow aspirate vary from a trephine biopsy? (2)

A

Gives more detailed views of specific blood cells

More liquid bone marrow is taken

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

The development of different blood cells from haemocytoblasts is controlled by…

A

Hormones/cytokines

Different concentrations of growth factors favours different development of haemocytoblast

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

Control and removal of senescent blood cells is via the ___________________ system

A

Reticuloendothelial system

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

What is the reticuloendothelial system?

A

A network in tissues/blood containing phagocytic cells

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

Name 4 phagocytes found in the reticuloendothelial system

A

Monocytes
Macrophages
Microglial cells
Kupffer cells

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

What are the main organs of the reticuloendothelial system?

A

Spleen

Liver

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

What happens to damaged/old blood cells (particularly RBCs) in the RES?

A

Blood passes through the spleen and RE cells dispose of senescent blood cells

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

What is the typical haemoglobin count for…

I) adult males
II) adult females

A

130-180 g/L

115-165 g/L

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

What is the typical mean cell volume?

A

80-100 fL

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

What is the typical platelet count?

A

150-400 x10^9/L

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

What is the diameter of a RBC?

A

8 micrometers

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

Changes in the components of the ________ _____________ of RBCs will change their shape

A

Cell membrane

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

Describe the structure of haemoglobin

A

Tetramer of 2 pairs of globin chains (2x alpha, 2x beta) each with its own haem group

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

Haemoglobin exists in which 2 configurations…

A

Deoxyhaemoglobin (T state)

Oxyhaemoglobin (R state)

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

Which gene codes for the synthesis of haemoglobin? Where are they found

A

Globin gene clusters

Chromosome 11 and 16

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

Are the individual globin chains synthesised independently or together?

A

Independently and the combined

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

At what age does the switch from foetal to adult haemoglobin take place?

A

3-6 months

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

What shape is the oxygen dissociation curve?

A

Sigmoid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Name three things that shift the oxygen dissociation curve to the right

A

2,3-BPG
H+ ions
Carbon dioxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Haemoglobin is broken down into…

A

Globin

Haem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What happens to the iron/amino acids and globin produced in the catabolism of haemoglobin?

A

It’s recycled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What happens to the haem produced in Hb catabolism?

A

Excreted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Give an example of a condition in which there is excess of red blood cell destruction

A

Haemolytic anaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Excess of red blood cell destruction (e.g. Haemolytic anaemia) causes an excess of

A

An excess of bilirubin formation

Leading to jaundice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Excess ________________ formation leads to jaundice

A

Bilirubin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Bilirubin is the breakdown product of…

A

Heme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What two things happen to bilirubin in the liver

A

Sent to the kidneys - excreted as urobilinogen in the urine

Transported in the biles to the intestines where it will be excreted in the faeces as stercobilin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

In which form is bilirubin excreted in the urine?

A

Urobilinogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

In which form is bilirubin excreted in the faeces?

A

Stercobilin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Which cells in the kidney detect reduced oxygen levels?

A

Interstitial peritubular cells of the kidney

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Reduced oxygen levels detected by the kidney result in an increased production of…

A

Erythropoietin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Which hormone causes an increased rate of erythropoiesis?

A

Erythropoietin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Erythropoietin stimulates the release of…

A

Red cells from the bone marrow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

By which two pathways does metabolism take place in red blood cells?

What does each pathway supply the red cells with?

A

Glycolysis
ATP generated

Pentose phosphate pathway
NADPH generated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Which molecule is metabolised in the pentose phosphate pathway?

A

Glucose-6-phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Apart from transporting/storing oxygen what is another function of iron in the body?

A

Integral part of many enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

How is iron excreted?

A

We have NO mechanism for excreting iron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

How much iron is lost each day from the body? From where in the body?

How are these losses made up?

A

Small amounts - 1-2 mg/day
Skin/Gut Cells

In the diet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Iron is available in the body in which 2 main forms?

A

Available (Functional) Form

Stored Form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Give 4 examples of function forms of iron?

A

Haemoglobin
Myoglobin
Tissue iron
Transported serum iron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Give two examples of stored forms of iron

A

Ferritin

Haemosiderin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Describe the solubility of ferritin and haemosiderin

A

Ferritin - soluble

Haemosiderin - insoluble

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

When in life might you see higher iron requirements?

A

During pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Where does most active iron come from?

A

From recycling in the body in the breakdown of RBCs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

In which form is iron predominantly stored in the liver?

A

Ferritin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Apart from as ferritin, iron in the liver is stored as…

A

Haemosiderin mainly in Kupffer cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Haemosiderin in the liver is predominantly stored in…

A

Kupffer cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Haem iron is mainly found in which foods?

Non-haem iron is mainly found in which foods?

A

Meats

Beans/pulses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Which is a better source of iron in humans - haem or non-haem iron?

A

Haem iron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Why is haem iron a better source of iron than non-haem?

A

Haem iron is already present in the ferrous form. Whereas non-haem iron is present in the ferric form and requires reduction by acid in the stomach.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

The iron in haem iron is present in which form?

A

Ferrous form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

The iron in non-haem iron is present in which form?

A

Ferric form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

How much iron do we require from the diet each day?

A

10-15 mg/day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What happens to iron in the ferrous form that we receive from the diet?

A

Binds to transferrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What converts iron from the ferric form into the ferrous form when it is taken in, in the diet?

A

Stomach acid - reduces ferric iron to ferrous iron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

In which part of the intestine is ferrous iron taken up?

By which cells?

A

Apical surface of the duodenum/upper jejunum

Enterocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

How is ferrous iron taken up at the apical surface of enterocytes in the duodenum/upper jejunum?

A

Transferrin-iron complex binds to transferrin receptors on the enterocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Ferrous iron is converted to which form inside the enterocytes?

A

Ferric iron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What two things can happen with the ferric iron in enterocytes?

A

Stored as ferritin

Travels in the blood in its ferrous form bound to transferrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

How is ferrous iron transported out of the enterocytes if it is to travel in the blood bound to transferrin?

A

By ferroportin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What is the action of ferroportin in enterocytes?

A

Exports ferrous iron out of the enterocyte

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What two things can happen to the ferrous iron exported from enterocytes?

A

Can be stored in the liver

Used in Hb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

How do fetal enterocytes differ from adult enterocytes?

A

Fetal enterocytes have receptors for milk iron (lactoferrin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Which type of cells contain the highest number of transferrin receptors?

A

Erythroid cells (cells that develop into RBCs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

Absorption of non-haem iron is better in which sorts of conditions?

A

Acidic conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Orange juice contains which acid?

A

Ascorbic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

How does precipitation/chelation of iron affect its absorption?

Which foods cause the precipitation/chelation of iron?

A

Inhibit its absorption

Tea, chapatis, antacids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

Name three factors that affect the regulation of iron absorption

A

Dietary factors
Body iron stores
Erythropoiesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

Dietary iron levels are sensed by…

A

The villi of enterocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

Name three control mechanisms that affect the regulation of iron absorption

A

Regulation of transports
Expression of receptors
Chemicals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

What is hepcidin?

A

Negative regulator of iron absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

Where is hepcidin secreted?

A

Liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

Where is hepcidin excreted?

A

Kidneys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

When is synthesis of hepcidin…

I) increased
II) decreased

A

In iron overload

When there is high erythropoietic activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

How does hepcidin work to reduce iron absorption?

A

Stops the action of ferroportin —> less iron absorption from the gut/less iron release from macrophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

Hepcidin leads to a build-up of non-functional iron in… (2)

A

Enterocytes/Macrophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

Is iron deficiency a symptom or a diagnosis?

A

Symptom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

Iron deficiency results from either… (2)

A

Insufficient intake/poor absorption

Increased use

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

What is pallor?

A

An unhealthy pale appearance

86
Q

Name 5 symptoms of anaemia

A 
Tiredness 
Pallor 
Reduced exercise tolerance 
Angina 
Palpitations
87
Q

What causes the pallor/reduced exercise tolerance seen in anaemia?

A

The reduced oxygen carrying capability of RBCs

88
Q

Name two cardiac symptoms of anaemia

A

Angina

Palpitations

89
Q

Name 5 signs on examination you may see with an anaemic patient

A

Pallor
Tachycardia
Increased respiratory rate
Epithelial changes - glossy tongue, spooning of nails

90
Q

Give two examples of epithelial changes you may see in someone with anaemia

A

Glossy tongue

Spooning of nails

91
Q

Name three blood film features seen in iron deficiency

A

Hypochromic RBCs
Microcytic RBCs
Anisopoikilocytosis

92
Q

What are hypochromic RBCs? How do they appear under a microscope?

A

RBCs with a low Hb count

They appear pale

93
Q

What are microcytic RBCs? What causes microcytic RBCs to be produced in iron deficiency?

A

Small RBCs

RBCs divide until they have a sufficient iron concentration

94
Q

What is anisopoikilocytosis of RBCs?

A

Change in size and shape of RBCs

95
Q

What is the most commonly used measure of iron status?

A

Ferritin

96
Q

What do reduced levels of ferritin in an individual indicate?

A

Iron deficiency

97
Q

Why might normal/increased levels of ferritin not exclude iron deficiency?

A

Ferritin is an acute phase protein and is seen in increased levels in inflammation/malignancy

98
Q

What other test can be used to test for iron deficiency other than ferritin?

A

CHR

99
Q

What does CHR test for? What is the problem with this test?

A

Tests for functional iron deficiency (amount getting to erythroid cells)

Levels stay low with thalassaemia

100
Q

Name 5 treatments for iron deficiency

A 
Dietary advice
Oral iron supplements 
Intramuscular iron injections 
IV iron 
Blood transfusion
101
Q

IV iron is usually avoided as a treatment for iron deficiency in the case of…

A

Anaphylactic shock

102
Q

When is transfusion given as a treatment for iron deficiency?

A

In severe anaemia with imminent cardiac compromise

103
Q

What increase in Hb levels should you expect to see when iron deficiency is treated?

A

20 g/L in 3 weeks

104
Q

Name two consequences of iron excess

A

Fe2+ can produce highly reactive hydroxyl and lipid radicals —»> damage to membranes, nucleic acids and proteins

Excess iron deposited in tissues - haemochromatosis

105
Q

What is haemochromatosis?

A

Disorder of iron excess resulting in end organ damage due to iron deposition

106
Q

Name 6 consequences of haemochromatosis

A 
Liver cirrhosis 
Diabetes mellitus
Hypogonadism 
Cardiomyopathy 
Arthropathy 
Skin pigmentation
107
Q

What are two types of haemochromatosis?

A

Hereditary haemochromatosis

Transfusion associated haemosiderosis

108
Q

In which way is hereditary haemochromatosis inherited?

A

Autosomal recessive

109
Q

Which mutation leads to hereditary haemochromatosis?

A

Mutation of HFE gene on chromosome 6 (p arm)

110
Q

What is the normal function of the HFE protein?

How will hereditary haemochromatosis affect this?

A

Competes with transferrin for binding to the transferrin receptor

Mutated HFE protein —> Can’t bind/compete —> Too much iron enters cells

111
Q

What is the treatment hereditary haemochromatosis?

A

Venesection

112
Q

What is venesection?

A

Removal of blood by IV

113
Q

A normal bag of blood contains ~400ml. How much iron will be present in this?

A

200mg of iron

114
Q

What happens in transfusion associated haemosiderosis?

A

Blood transfusion results in a gradual accumulation of iron and iron overload

115
Q

In what conditions may transfusion associated haemosiderosis be seen?

A

In transfusion dependent anaemias

116
Q

What is the treatment for transfusion associated haemochromatosis? (2)

A

Limiting transfusion

Iron chelating agents

117
Q

What is anaemia?

A

Inability of RBCs to deliver enough oxygen to the tissues

118
Q

Anaemia can be as a result of not enough… (2)

A

RBCs

Hb in RBCs

119
Q

What is the function of the RES?

A

Recycles and removes dead/damaged blood cells

120
Q

What is the main organ of the RES?

A

Spleen

121
Q

Name two important cells of the RES

A

Macrophages

Kupffer cells

122
Q

Name two causes of loss of red cells that can result in anaemia

A

Reduced erythropoiesis

Dyserythropoiesis

123
Q

What are three causes of reduced erythropoiesis?

A

Chronic kidney disease
Empty bone marrow due to chemotherapy/toxic insult
Bone marrow infiltrated by cancer cells/fibrous tissue

124
Q

How does chronic kidney disease result in reduced erythropoiesis?

What is the treatment for someone with chronic kidney disease causing anaemia?

A

Stops making erythropoietin —> anaemia

Give erythropoietin

125
Q

Name two things that can cause ‘empty bone marrow’ and as a result reduced erythropoiesis and anaemia

A

Chemotherapy

Toxic insult - e.g. Parvovirus

126
Q

Why can ‘empty’ bone marrow result in reduced erythropoiesis?

A

Bone marrow is unable to respond to erythropoietin

127
Q

Name two diseases that can result in dyserythropoiesis

A

Anaemia of Chronic Disease

Myelodysplastic Syndromes

128
Q

In what sort of conditions is anaemia of chronic disease seen? (2)

A

Inflammatory conditions

Chronic Infections

129
Q

Name three features of anaemia of chronic disease

A

Iron stored in macrophages is not released for use in bone marrow
Circulating red cells have a reduced lifespan
Bone marrow shows a lack of response to erythropoietin

130
Q

Is Anaemia of Chronic Disease due to iron deficiency?

A

No

131
Q

The anaemia seen in Anaemia of Chronic Disease is of which type?

A

Can be microcytic, normocytic or macrocytic

132
Q

What is the treatment for Anaemia of Chronic Disease?

A

No specific treatment - treat the underlying cause

133
Q

How will CRP and ferritin levels be affected in Anaemia of Chronic Disease?

A

Often raised

134
Q

In which people is myelodysplastic syndrome seen?

A

Elderly

135
Q

What happens in myelodysplastic syndrome?

A

Production of abnormal clones of marrow stem cells

136
Q

How is diagnosis of myelodysplastic syndrome made?

A

Microscopy of blood/bone marrow cells - RBCs will be defective and large (macrocytic)

137
Q

What type of anaemia will be seen in myelodysplastic syndromes?

A

Macrocytic anaemia that gets progressively worse

138
Q

Why is progressive anaemia seen in myelodysplastic syndromes?

A

Cells are prematurely destroyed by the RES

139
Q

What is the treatment for anaemia as a result of myelodysplastic syndromes? (2)

A

Chronic transfusions of red cells

Stem cell transplant

140
Q

Define megaloblastic anaemia

A

Anaemia due to deficiency in building blockers for DNA synthesis as a result of vitamin B12 and/or folate deficiency

141
Q

What is B12 and folate essential for?

A

Nuclear divisions and nuclear maturation (DNA synthesis)

142
Q

A deficiency in B12/Folate will result in…

A

Nuclear maturation/cell divisions that lag behind cytoplasmic development

143
Q

How will the RBCs in megaloblastic anaemia appear?

A

Large (macrocytic) with large nuclei and open chromatin

144
Q

Vitamin B12 is synthesised by…

A

Microorganisms

145
Q

B12 can be stored in the body for how long?

A

Years

146
Q

How is vitamin B12 acquired in the diet?

A

By eating foods of animal origin

147
Q

How is vitamin B12 absorbed and transported to the bone marrow?

A

Combined with intrinsic factor (glycoprotein)
IF-B12 complex bind to cells in the ileum
B12 absorbed, IF destroyed
B12 binds to transcobalamin in the portal blood

148
Q

Which cells of the body produce intrinsic factor?

A

Parietal cells of the stomach

149
Q

Where is vitamin B12 absorbed in the gut?

A

Ileum (bound to IF - IF destroyed, B12 absorbed)

150
Q

Which plasma protein does B12 bind to in the portal blood?

A

Transcobalamin

151
Q

Name 4 causes of B12 deficiency

A

Dietary deficiency
Pernicious anaemia
Disease of the terminal ileum
Congenital deficiency of transcobalamin

152
Q

What is pernicious anaemia?

A

Where autoimmune disease affects parietal cells of the stomach causing a lack of intrinsic factor —> B12 deficiency —> anaemia

153
Q

Apart from an autoimmune disease, in which other cases may pernicious anaemia be seen?

A

In case of gastrectomy

154
Q

Name a disease of the terminal ileum that can cause B12 deficiency

A

Crohn’s disease

155
Q

In which foods is folate present?

A

Most foods - particularly yeast, liver and leafy greens

156
Q

Folate is particularly present in which foods? (3)

A

Liver
Leafy greens
Yeast

157
Q

Where does absorption of folate in the gut take place?

A

In the duodenum and jejunum

158
Q

What happens to dietary folate that is consumed?

A

It is all converted to methylTHF —> circulates in the plasma

159
Q

Folate is essential for…

A

DNA synthesis

160
Q

What is dietary folate converted to in the body?

A

MethylTHF

161
Q

Name 5 causes of folate deficiency

A 
Dietary deficiency 
Increased use 
Proximal small bowel disease
MethylTHF drugs 
Alcoholism
162
Q

When may increased use of folate be seen (possibly resulting in a deficiency)?

A

During pregnancy

163
Q

Give an example of a proximal small bowel disease

A

Crohn’s disease

164
Q

How will the blood film in vitamin B12/folate deficiency appear?

A

Macrocytic red cells

Hyper-segmented neutrophils

165
Q

How do RBCs appear in B12/folate deficiency?

How do neutrophils appear in B12/folate deficiency?

A

Macrocytic

Hyper-segmented

166
Q

As B12/Folate deficiency progresses what may be seen?

A

Pancytopenia

167
Q

What is vitamin B12 deficiency associated with (other than anaemia)?

A

Neurological disease
Depression
Dementia

168
Q

In sickle cell disease, which gene is mutated?

A

The gene coding for the B-globin chain

169
Q

What mutation is seen in sickle cell disease? In which position?

A

Valine —> Glutamate

6th amino acid

170
Q

What happens to HbS in RBCs?

A

It polymerises, causing an inflexible sickled shape

171
Q

What happens if someone is a HbS carrier and has sickle cell trait?

A

They will have mild, asymptomatic anaemia and be protected against malaria

172
Q

How does HbS give up its oxygen compared to HbA?

A

HbS gives it up readily

173
Q

What clinical problems can result from sickle cell disease? (3)

A

Blocking of small blood vessels
Pain
Problems affecting chest/spleen

174
Q

Beta-thalassaemia is most common in which part of the world?

A

South Asia

Mediterranean

175
Q

Alpha-thalassaemia is most common in which part of the world?

A

Far East

176
Q

How will red blood cells appear in someone with thalassaemia? Why?

A

Hypochromic (Pale)
Microcytic

Due to low intracellular levels of Hb

177
Q

There is increased destruction of red cells in the _________ due to their incorrect globin chain make-up

A

Spleen/Bone Marrow

178
Q

Name three compensatory mechanisms/consequences of thalassaemia

A

Extramedullary haemopoiesis
Stimulation of erythropoietin
Iron overload

179
Q

What is extramedullary haemopoiesis? What can it result in?

A

Where there is an attempt to produce more blood cells out of the bone marrow into the bone cortex

Impaired growth/skeletal abnormalities

180
Q

Why might iron overload be seen in someone with thalassaemia?

A

They receive transfusions and may have excessive absorption of dietary iron as well

181
Q

Name 4 treatments for thalassaemia

A

Transfusions
Iron chelation
Folic acid
Stem cell transplantation

182
Q

When is onset of beta-thalassaemia? Why at this time?

A

6-9 months after birth

There is a switch from HbF to HbA

183
Q

Is onset of a-thalassaemia before or after birth?

A

Before birth

184
Q

What condition can result from abnormalities of the proteins making up the red cell membrane?

A

Anaemia

185
Q

Name two inherited abnormalities of the structure of RBCs (as a result of their membrane proteins)

A

Hereditary spherocytosis

Hereditary elliptocytosis

186
Q

What happens to the shape of RBCs in hereditary elliptocytosis?

What happens to the shape of RBCs in hereditary spherocytosis?

A

Elliptical shaped

Sphere shaped

187
Q

Name three things that cause structural abnormalities to RBCs (acquired abnormalities)

A

Mechanical damage to red cells
Burns
Drowning

188
Q

Why do abnormalities in the structure of RBCs cause anaemia?

A

Leads to RBCs being removed by the RES at a higher rate than normal —> Anaemia

189
Q

Give an example of an enzyme that if deficient in RBCs can result in anaemia

A

Glucose-6-phosphate dehydrogenase

190
Q

How can acute blood loss (trauma/haemorrhage) cause anaemia?

A

Hypovolaemic shock —> Anaemia

191
Q

Name two causes of chronic blood loss that can result in anaemia

A

Excessive menstruation

Gastric ulceration

192
Q

Anaemia due to blood loss can present as which type of anaemia? Why?

A

Microcytic

Iron deficient state in the body due to bleeding

193
Q

Haemolytic anaemia is caused by…

What are two types of haemolytic anaemia?

A

The destruction of red blood cells

Intravascular
Extravascular

194
Q

What is intravascular haemolytic anaemia?

What is extravascular haemolytic anaemia?

A

Occurs within blood vessels

Occurs outside blood vessels and in the RES by macrophages

195
Q

What happens in autoimmune haemolytic anaemia?

A

Autoantibodies (IgG) bind to red cell membrane protein cause their destruction

196
Q

What three things will be seen in someone with autoimmune haemolytic anaemia?

A

Increased reticulocytes
Raised bilirubin (jaundice)
Increased LDH

197
Q

What are reticulocytes?

A

Immature RBCs

198
Q

How is anaemia classified (3 ways)?

A

By mechanism
By size
By presence or absence of reticulocytosis

199
Q

What value do microcytic RBCs take?

What value do macrocytic RBCs take?

A

< 80fl

> 100fl

200
Q

Patients with overproduction of blood cells due to myeloproliferative disorders often have a mutation in a copy of which gene? On which chromosome?

A

JAK2 Gene

Chromosome 9

201
Q

How are levels of blood cells affected in Polycythaemia Vera?

A

There are too many red cells

202
Q

What is polycythaemia? What investigation can indicate polycythaemia?

A

A group of varied disorders with an increase in circulating red cells

Measurement of the haematocrit

203
Q

How will the haematocrit is someone with Polycythaemia Vera be affected?

A

Will be persistently raised

204
Q

What is haematocrit?

A

The ratio of the volume of RBCs against the total blood volume

205
Q

How does Polycythaemia Vera affect the consistency of blood?

A

Thick, concentrated blood

206
Q

What haematocrit value will indicate Polycythaemia Vera?

A

Raised

> 0.52 - MEN
0.48 - WOMEN

207
Q

As well as a high haematocrit how else can Polycythaemia Vera be diagnosed?

A

By a raised cell mass (>25%)

208
Q

What is relative polycythaemia?

A

Where there is normal red cell mass but lower plasma volume

209
Q

What is absolute polycythaemia?

A

Where there is increased cell mass

210
Q

Name 4 clinical features of polycythaemia

A

Arterial thrombosis
Venous thrombosis
Haemorrhage into skin/GI tract
Gout

211
Q

Name two treatments for Polycythaemia Vera

A

Venesection

Aspirin (75 mg)

212
Q

Why is venesection carried out in the management of Polycythaemia Vera?

Why is aspirin carried out in the management of Polycythaemia Vera?

A

Maintains correct haematocrit

Thins blood

MEH (9 decks)

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