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Flashcards in BLOOD Deck (51)
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1

what is haematocrit?

the ratio of volume of RBC to total volume

2

what is haematopoiesis?

the formation of new blood cells and platelets

3

what is anaemia?

reduced haemoglobin or numbers of RBCs
often due to iron deficiency

male < 130 g/L
female < 110 g/L

4

what is haemostasis?

the arrest of bleeding
this involves the physiological processes of coagulation and contraction of damaged blood vessels

5

what is haemophilia?

the inability to make new blood clots due to factor VIII deficiency (haemophilia A) or factor IX (haemophilia B)

6

what are the components of blood?

fluid = 55%
cellular = 45%

7

where are precursor cells found in adults?

in axial bone marrow

8

where are precursor cells found in children?

in bone marrow of all bones

9

where are precursor cells found in embryos?

yolk sac
liver
spleen
bone marrow

10

what are stem cells?

they are pluripotent and can differentiate into any blood cell (RBC, WBC or platelets)

11

what is the process of red blood cell production?

erythropoiesis

12

what is the hormonal stimulating factor for erythrocyte production? Where is it made?

erythropoietin (EPO)
made in kidneys

13

what is the process of white blood cells production?

myelopoiesis

14

what is the hormonal stimulating factor for white blood cell production? what does it stimulate?

granulocyte-macrophage colony stimulating factor (GMCSF)
stimulates production of myeloblastic WBCs and not lymphoid cells

15

what is the process of platelet production?

thrombopoiesis

16

what is the hormonal factor for platelet production? What is it's effect?

thrombopoietin (TPO)
leads to increased megakaryocytes which platelets bud off from

17

what is the lifespan of erythrocytes?

120 days

18

what is the structure of erythrocytes?

- no nucleus and no mitochondria
- biconcave
- contain haemoglobin

19

how are red blood cells removed?

by spleen, liver and bone marrow and through blood loss

20

what is the role of haemoglobin?

carries O2 from lungs to tissues

21

what is the structure of haemoglobin?

tetrametric protein with 4 globin chains
each has a haem group - capable of oxygen binding

22

what is the difference between adult and foetal haemoglobin?

adult = 2 x alpha and 2 x beta haemoglobin chains

foetal = 2 x alpha and 2 x gamma haemoglobin chains

23

what is thalassaemia?

mutations / absence of alpha or beta chains in adult haemoglobin

24

what are the symptoms of anaemia?

pallor
tachycardia
hyperventilation on exertion
malaise
angina

25

what are the causes of anaemia?

- acute blood loss
- production mismatches
- increased removal of RBCs
- deficiencies of iron, folate or vitamin B12

26

what is hypoplastic anaemia?

doesn't produce enough blood cells

27

what is dyshaemotpoeitic anaemia?

ineffective production of blood cells

28

what is haemolytic anaemia?

increased removal of RBC

29

what is macrocytic anaemia?

deficiency in folate

30

what is pernicious anaemia?

deficiency in vitamin B12