physiology blood

Question 1

where does haematopoesis largely occur and from what cells

Answer 1

pluripotent stem cells in bone

Question 2

precursor of red blood cells

Answer 2

reticulocyte

Question 3

precursor platelet

Answer 3

megakaryocyte

Question 4

structure + function eosinophil

Answer 4

bilobed, red granules // fight parasites + hypersensitivity

Question 5

structure + function basophil

Answer 5

very rare, deep purple, unsudre function

Question 6

structure + function neutrophil

Answer 6

multilobed // first defence cell // infection, trauma, infection

Question 7

types of agranulocytes

Answer 7

monocyte (macrophage) + lymphocyte

Question 8

where is bone marrow extracted

Answer 8

posterior iliac crest (trabecular bone)

Question 9

Hb structure

Answer 9

2 alhpa and 2 betas subunit // iron binds with O2 at centre of haem group

Question 10

what type of iron does o2 bind too

Answer 10

Fe2 not Fe3

Question 11

how is erythropoesis stimulated

Answer 11

kidney senses hypoxia –> EPO –> Bone marrow

Question 12

where are RBCs broken down

Answer 12

spleen (and liver)

Question 13

what is blood broken down too

Answer 13

bilirubin + iron (bili excreted in bile)

Question 14

what transports CO2

Answer 14

10% undissolved // 30% bound to Hb or carbamino Hb // 60% HCO3

Question 15

how many molecules of O2 can 1 Hb carry

Answer 15

4

Question 16

subunits foetal Hb

Answer 16

2 alpha 2 gamma

Question 17

function foetal Hb

Answer 17

saturates O2 at similar O2 (can take blood from maternal circulation)

Question 18

what does a curve shift to the right shift

Answer 18

more O2 released // high [H+] // high DPG // high temp // high CO2

Question 19

what does a curve shift to the left shift

Answer 19

less O2 released // low [H] // low DPG // low temp // HbF, methaglobin, carboxyhaemoglobin

Question 20

how is Hb synthesised

Answer 20

mitochondrion: make porphin ring + Fe2+ –> cytoplasm: they bind to make haem + join with subunits –> Hb

Question 21

what is primary haemostasis

Answer 21

platelet plug

Question 22

what is secondary haemostasis

Answer 22

fibrin clot

Question 23

how long do platelets live

Answer 23

7-10 days

Question 24

what is exposed + released when endothelium is damaged (ie bleeding) that causes platelets to bind to site of injuery

Answer 24

collagen –> von willibrand factor (+ other proteins)

Question 25

once platelets have bound to endothelium, what do they release to aggregate more platelets

Answer 25

thromboxin A2 // ADP // glocoprotein II + III

Question 26

what can cause failure of platelet plug (broadly)

Answer 26

vascular weakness + lacking collagen eg old age // rediced platelets eg thrombocytopenia // VWF deficient

Question 27

what tests indicate failure or platelet plug formation

Answer 27

platelet count

Question 28

what do platelets release to attract clotting factors

Answer 28

phospholipids

Question 29

what is the initiation phase/ extrinsic pathway of fibrin clot

Answer 29

TF is released from epithelium which activates VII

Question 30

what is the propagation phase/ intrinsic pathway of fibrin clot

Answer 30

TF/ VII activate --> factor V + X which convert: prothrombin (IIa) --> thrombin (II)

Question 31

what blood marker shows intrinsic pathway function

Answer 31

prothrombin time (PT)

Question 32

what blood marker shows extrinsic pathway function

Answer 32

APTT

Question 33

what is the amplification phase of fibrin clot

Answer 33

thrombin coverts: fibrinogen --> fibrin // thrombin also activates VIII + IX // VIII + IX then also activate more V + X

Question 34

what breaks down the fibrin clot

Answer 34

plasmin

Question 35

how is plasmin activated

Answer 35

tPA converts plasminogen --> plasmin

Question 36

what is the breakdown product of fibrin clots

Answer 36

D-Dimer

Question 37

what causes failure of fibrin clot (broadly)

Answer 37

haemophillia // DIC

Question 38

how do serine protease inhibitors act as natural anticoags

Answer 38

produce antithrombin (AT III) which inhibits thrombin // inihibts fibringinogen --> fibrin // inhibits VIII + IX --> X + V

Question 39

how do protein C+S anticoag

Answer 39

released by thrombin at end of bleeding --> reduce clotting factors

Question 40

where are clotting factors made

Answer 40

liver (except VIII)

Question 41

function of Vit K in fibrin clot

Answer 41

carboxylates factor II (prothrombin), VII, IX, X, (and protein C)

Question 42

how is vit K absorbed

Answer 42

bile salts

Question 43

what are myloid cells

Answer 43

precursors of all RBCs, platelets, and myloblasts (basophil, neutrophil, eisonhil, monocyte (-->macrophage)

Question 44

what are lymphoid cells

Answer 44

precurors of NKs, T lymphoctes, B lymphoctes

Question 45

what are prescursors of plasma cells

Answer 45

B lymphoctes

Question 46

what organs are involved in the secondary lymphoid system

Answer 46

spleen and lymph

Question 47

what does the TIBC look at

Answer 47

transferrin levels

Question 48

when is TIBC raised

Answer 48

iron deficiency + pregnancy

Question 49

how is transferrin saturation calculated

Answer 49

serum iron / TIBC

Question 50

when is ferritin raised or lowered

Answer 50

(iron stores) raised in inflammation disorders eg RA // low in iron deficiency

Question 51

bloods, TIBC, ferritin in anaemia chronic disease

Answer 51

normo or hypochromic, normocytic anaemia // reduced TIBC // normal ferritin

Question 52

what is ferritin

Answer 52

protein that binds to iron and stores it

Question 53

causes raised ferritin without iron overload

Answer 53

inflammation // alcohol // liver disease // CKD // malignancy

Question 54

causes raised ferritin with iron overload

Answer 54

primary iron overload (haemochromatosis) // secondary iron overload (repeat transfusions)

Question 55

what test determines if iron overload is present

Answer 55

transferrin saturation (>45% females and >50% males)

Question 56

cause reduced ferritin

Answer 56

iron deficiency