anatomy and physiology

Question 1

what is haematopoeisis?

Answer 1

formation of blood cellular components

Question 2

what is primitive haematopoeisis?

Answer 2

production of erythrocytes and macrophages - essential during embryonic development

Question 3

what is the most primitive haematopoietic cell?

Answer 3

haematopoietic stem cell

Question 4

what is definitive haematopoiesis?

Answer 4

occurs later in developement - produces: erythroid myeloid-progenitors, allows all blood lineages in adults by haematopoietic stem cells (multipotent)

Question 5

where does embryonic haematopoiesis occur during 14-19 days post fertilisation?

Answer 5

yolk sac

Question 6

where is haematopoiesis during 2nd trimester?

Answer 6

liver

Question 7

where does adult haematopoiesis occur?

Answer 7

bone marrow in long bones and thymus - they contain red and yellow marrow
others contain yellow marrow

Question 8

in infants and young children which bones allow haematopoiesis?

Answer 8

most of them - contains red marrow

Question 9

what does yellow marrow do?

Answer 9

provide structural support

Question 10

if their is insufficient haematopoiesis within an adult what happens?

Answer 10

red marrow may expand to liver and spleen - extra medullary haematopoiesis

Question 11

what % of blood is haemocrit?

Answer 11

45% - erythrocytes - dense

Question 12

what % is plasma within the blood?

Answer 12

55% - water (mainly) but has protein (albumin, Ig, fibrinogen) and others (vitamins, lipids, hormones)

Question 13

what % is the buffy coat within blood?

Answer 13

<1% - leukocytes and platelets

Question 14

describe the structure of erythrocytes

Answer 14

• non nucleated cells
• 7 microns in diameter
• Biconcave disc with central area of pallor
• Contains red cell membrane, metabolic machinery and haemoglobin

Question 15

how many days does a RBC remain in circulation for?

Answer 15

120 days

Question 16

describe haemoglobin structure

Answer 16

• 4 polypeptide globin chains each containing a haem group
• Adult haemoglobin (HbA) contains 2 alpha and 2 beta chains
• Haem group: ferrous atom, polyphyrin ring (allows reversible binding)

Question 17

where does erythropoiesis occur?

Answer 17

bone marrow

Question 18

what is EPO?

Answer 18

growth factor that facilitates erythrocyte production

Question 19

how does the body maintain RBC haemostasis?

Answer 19

constantly destroying old/ damages RBC (haemolysis) and replacing new

Question 20

where does extravascular haemolysis occur?

Answer 20

outside the blood vessels eg spleen - macrophage RBC destruction

Question 21

what do kuppler cells do within RBC lysis?

Answer 21

kuppler are located within liver
they phagocytose haemoglobin

Question 22

what happens to the iron after haemolysis?

Answer 22

gets released back into circulation after a few days or stored in liver as ferritin

Question 23

what is polyphorin ring converted to?

Answer 23

bilirubin

Question 24

what happens to globin aspect during RBC breakdown?

Answer 24

digested by peptidases to produce amino acids - can be metbaolised or recycled

Question 25

what is haem broken down into?

Answer 25

iron and bilirbin

Question 26

how does the body prevent iron oxidation following RBC breakdown?

Answer 26

released iron must be bound to a protein to prevent iron being oxidised into ferric state (Fe2+)

Question 27

where does intravascular haemolysis occur?

Answer 27

within blood vessels

Question 28

name some granulocytes

Answer 28

neutrophils basophils and eosinophils

Question 29

what does neutrophils target?

Answer 29

bacteria fungi and foreign debris

Question 30

what do monocytes target or develop into?

Answer 30

target - clean up damaged cells as they develop into macrophages

Question 31

what do eosinophils target?

Answer 31

kill parasites, cancer involved in allergic response

Question 32

what do lymphocytes target?

Answer 32

viruses and produce antibodies

Question 33

what are basophils involved with?

Answer 33

allergic response

Question 34

where do monocytes become macrophages?

Answer 34

within tissues

Question 35

what is the role of platelets?

Answer 35

clump together in platelet aggregation and plug gaps where blood clots form

Question 36

what is the daily intake of iron?

Answer 36

15mg

Question 37

how much iron is absorbed daily?

Answer 37

1mg

Question 38

what conditions is iron best absorpbed in?

Answer 38

acidic - best to take supplements between meals

Question 39

where does iron absorbption occur?

Answer 39

stomach and duodenum - enterocytes

Question 40

why do coeliac sometimes have anaemia?

Answer 40

villious atrophy in duodenum and jejunum

Question 41

what state is Fe2+?

Answer 41

ferrous state

Question 42

what state is Fe3+?

Answer 42

ferric state - free iron

Question 43

which iron state can be absorbed?

Answer 43

- Free iron in ferric state requires reduction to ferrous state for absorption – acidic conditions of stomach acid. Ascorbic acid = vit C reduces. Duodenal cytochrome b ferric reductase – found on brush border of duodenal enterocytes

Question 44

what is haem?

Answer 44

polyphrin ring containing iron in ferrous state

Question 45

how does Hb enter enterocytes?

Answer 45

- Hame – endocytosed by enterocytes where it is subsequently digested by haemoxidases to release ferric iron. Ferrous iron binds to DMT -1 to cross brush border

Question 46

how does haemoglobin get stored within enterocytes?

Answer 46

- Inside enterocytes: can bind to apoferritn to form ferritin – stored within enterocyte (needs to be ferric state)

Question 47

how does Hb leave enterocyte and re-enter blood stream?

Answer 47

- Ferrous ions are transported out of enterocyte and are oxidised to ferric state by hepaestin for further transfer exported out by ferroportin 1

Question 48

what does transferrin do?

Answer 48

transports ferritin ions - to tissues that require iron

Question 49

what is TIBC?

Answer 49

total iron binding capacity - transferrin unbound to iron

Question 50

what is haemosiderin?

Answer 50

insoluble form of iron, mainly found on macrophages

Question 51

what is the urine test for multiple myeloma?

Answer 51

bence-jones urine test