Haemopoiesis

Question 1

What is haemopoiesis?

Answer 1

the formation of blood cells

Question 2

what is proliferation?

Answer 2

the expansion of a cell line

Question 3

what is differentiation?

Answer 3

the variation of a cell line

Question 4

what does a pluripotent stem cell differentiate into?

Answer 4

myeloid lineage or lymphoid lineage

Question 5

what are the myeloid cells?

Answer 5

erythrocytes, granulocytes, monocytes and platelets

Question 6

what are the lymphoid cells?

Answer 6

t and b lymphocytes

Question 7

can progenitor cells be microscopically visualized?

Answer 7

no, only when grown in culture

Question 8

what are progenitor cells also known as?

Answer 8

colony forming units

Question 9

where are pluripotent and progenitor cells found?

Answer 9

bone marrow

Question 10

where does foetal haemopoiesis occur?

Answer 10

bone marrow, liver, lymph nodes and spleen

Question 11

where does embryonic haemopoiesis occur?

Answer 11

in the yolk sac

Question 12

what is the area vasculosa?

Answer 12

part of the yolk sac where blood vessels are found

Question 13

what is intramedullary haemopoiesis?

Answer 13

haemopoiesis occurring in the bone marrow

Question 14

what is extramedullary haemopoiesis?

Answer 14

haemopoiesis occurring outside of the bone marrow

Question 15

what are the phases of haemopoiesis?

Answer 15

1. mesoblastic/embryonic
2. hepatosplenic
3. myeloid/bone marrow

Question 16

when does the mesoblastic phase of haemopoiesis occur?

Answer 16

first few weeks to two months of gestation

Question 17

what are the types of primitive haemoglobin?

Answer 17

Gower and Portland

Question 18

what type of cells are produced by primitive haemopoiesis?

Answer 18

mainly erythrocytes

Question 19

where does the hepatosplenic phase of haemopoiesis occur?

Answer 19

mainlyin liver but also in spleen

Question 20

when does hepatosplenic haemopoiesis occur?

Answer 20

2-7 months, max 4

Question 21

what is the main type of Hb produced in the hepatosplenic phase?

Answer 21

Hb F

Question 22

when does the myeloid phase occur?

Answer 22

5-9 months and continues throughout life

Question 23

what does Hb A consist of?

Answer 23

4 haem molecules attached to 4 globin chains (2a and 2B)

Question 24

where does adult haemopoiesis take place?

Answer 24

red marrow of the bone marrow

- femur, cranium, hips, pelvis, spine, ribs, sternum

Question 25

what does yellow marrow act as?

Answer 25

a fat store

Question 26

what regulates blood cell production?

Answer 26

growth factor hormones
environmental factors
oxygen levels
cytokines