Lecture 1 - Blood & Bone Marrow

Question 1

Haematopoesis?

Answer 1

process by which mature blood cells are formed from stem cells of the bone marrow, short lived so needs to be precise and constant and adjustable (bleeding, infection)

Question 2

Haematopoetic Tissues?

Answer 2

bone marrow (sternum, ribs, scarum, vertebrae, long bones (children)) and spleen

Question 3

Embryology of haemopoetic tissues?

Answer 3

primitive stem cells from mesoderm in blood islands of yolk sac & definitive stem cells of AGM region -> fetal liver -> bone marrow

Question 4

Scarring of marrow?

Answer 4

myelofibrosis (w splenomegaly)

Question 5

Cellularity?

Answer 5

presence of haemotopoetic cells in marrow, 30-70%, decreases with age and replaced with fat cells

Question 6

Haematopoetic stem cell niches?

Answer 6

endosteal: osteoblast, supports HSC in self renewal and differentiation, endothelial

Question 7

Life spans?

Answer 7

RBC 120 days, platelets 5-6 days, neutrophil 5-6 hrs

Question 8

Progenitor cells?q

Answer 8

intermediate stage from stem cells, lymphoid progenitor (B and T cells) or myeloid progenitor (RBC, leukocytes and platelets)

Question 9

HCGs?

Answer 9

1 in 10,000-100,000 of blood cell populaiton, self renew or generate all different cell types, express antigen CD34 for identification

Question 10

Sources of HCGs?

Answer 10

bone marrow, umbilical cord, peripheral blood

Question 11

Stimulating RBC production?

Answer 11

eythropoetin

Question 12

stimulating platelet production?

Answer 12

thrombopoietin

Question 13

stimulating neutrophil production?

Answer 13

granulocyte colony stimulating factor (G-CSF)