Anemia

Question 1

red blood cells

Answer 1

membraneous discs containing a Hb solution
lifespan - 120 days

Question 2

RBC production

Answer 2

manufactured in bone marrow
(marrow - stem cells to proerythroblas to normoblasts)

Normoblast loses nucleus and some organelles to form reticulocyte
(blood - reticulocytes loses remianing organelles to form erythrocyte)

stimulated by erythropoeitin and requires iron, vit B12 and folate

Question 3

normoblasts

Answer 3

manufacture Hb

Question 4

erythropoiesis

Answer 4

RBC production and maturation

Question 5

RBC formation

Answer 5

1. kidneys detect reduced O2 carrying capacity of blood
2. kidneys respond by secreting erythropoietin into blood
3. erythropoietin stimulates erythropoiesis by bone marrow
4. addition of circulating erythrocytes increases O2 carrying capacity of blood
5. increase O2 carrying capacity of blood relieves initial stimulus that triggered EPO secretion by kidneys

Question 6

functional definition of anemia

Answer 6

circulating red cell mass insufficient to meet oxygen requirements of tissues

Question 7

clinical definition of anemia

Answer 7

reduction of Hb concentration to below normal levels

<13g/dL (men) <12g/dL (women)

Question 8

acute clinical manifestations of anemia

Answer 8

depends on severity of Hb losses, shock

Question 9

chronic clinical manifestations of anemia

Answer 9

headache, light headedness, fatigue, nail/hair cheilitis, tinnitus, vertigo, palpitations, menstrual irregularities, exertional dyspnoea, oedema, angina/claudication, cardiac failure, fever, GI discomfort

Question 10

classification of anaemia

Answer 10

reduced RBC production
increased destruction
loss of RBC from circulation

Question 11

causes of reduced production of RBC

Answer 11

defective precursors - iron deficiency, anemia of chronic disease, reduced EPO of renal disease, bone marrow failure, drugs, leukemia, cancer

defective maturation - B12, folate deficiency, thalassaemia/sickle cell, infections

Question 12

causes of increased breakdown

Answer 12

genetic membrane/enzyme/Hb disorders, autoimmune, mechanical (heart valves), infection, drugs (penicillin)

Question 13

cause of loss of RBC from circulation

Answer 13

bleeding

Question 14

investigation of anaemia

Answer 14

Clinical history and symptoms:
1. bleeding (menstrual, GI, post menopausal, urinary tract)
2, nutrition (deficiencies)
3, drug and alcohol use
4. other medical problems

examination: paleness, underlying conditions
other: FBC and MCV

Question 15

hematocrit (Hct)

Answer 15

% of RBC mass to original blood volume

Question 16

mean cell volume

Answer 16

(Hct / RBC) *10

Question 16

normocytic

Answer 16

normal MCV 80-100 fL

Question 17

macrocytic

Answer 17

high MCV >100

due to pregnancy, B12/folate deficiency, liver disease, hypothyroidism, haemolysis

Question 18

microcytic

Answer 18

low MCV <80

due to iron deficiency, thalassemia

Question 19

iron deficiency anaemia causes

Answer 19

common in women and young children

chronic blood loss (menstruation), poor diet, malabsorption (coeliac, IBD), increased requirement (Pregnancy) and hookwork (decrease availability, malabsorption)

Question 20

management of iron deficiency anaemia

Answer 20

oral or parenteral iron therapy, treat underlying cause

Question 21

alcohol impact on anaemia

Answer 21

causes bone marrow suppression, associated with nutritional deficiencies (displaces), predisposition to GI blood loss (ulcers) and can cause haemolysis

Question 22

megaloblastic anaemia

Answer 22

folate/B12 deficiency

Question 23

folate deficiency causes

Answer 23

poor diet (alcoholics), malabsorption (coeliac), excess requirement (pregnancy, haemolytic anaemia), chronic inflammation, malignancy, drugs

Question 24

B12 deficiency causes

Answer 24

poor diet, pernicious anaemia, gastric surgery, Crohn's disease

Question 25

vitamin B12 absorption

Answer 25

requires intrinsic factor and functioning bowel

Question 26

haemoglobinopathies

Answer 26

haemoglobin + pathology genetic defects in Hb chain synthesis (a/B thalassemia, sickle cell anaemia)

Question 27

sickle cell anaemia

Answer 27

inherited beta-chain disorder where valine instead of glutamic A

Question 28

heterozygous sickle cel anaemia

Answer 28

no clinical significance, carrier

Question 29

homozygous sickle cell anaemia

Answer 29

in conditions of low oxygen, cells sickle and haemolyse, which can cause thrombosis can cause joint problems, chronic lung disease, acute abdominal pain and stroke

Question 30

acute chest syndrome

Answer 30

sickle cells clump and block blood vessels to lungs symptoms include sudden chest pain, cough, fever and trouble breathing common admission, cause death

Question 31

veno-occlusive crises

Answer 31

sickle cells clump and block blood vessels to body major symptom is intense pain all over