Hematopoiesis

Question 1

what are the two general lineages of differentiation in hematopoiesis?

Answer 1

lymphoid and myeloid

Question 2

can progenitor cells create identical daughter cells?

Answer 2

no

Question 3

granulocyte G-CSF

Answer 3

secreted by macrophage/endothelium/fibroblasts. stimulate formation of granulocytes and increases granulocyte metabolism (also stimulates leukemic cells)

Question 4

granulocyte and macrophage GM-CSF

Answer 4

secreted by t-cells, endothelium, fibroblasts. stimulate formation of granulocytes and macrophages

Question 5

macrophage M-CSF

Answer 5

secreted by macrophages, endothelium, fibroblasts. stimulates formation of macrophages and increases macrophagic anti tumor activity

Question 6

interleukin 3

Answer 6

t-cells. stimulates formation of all myeloid cells

Question 7

erythropoietin

Answer 7

renal interstitial cells. RBC formation

Question 8

growth factors have the largest effect on which stage in cell development?

Answer 8

blast cells and progenitors

Question 9

at what stage do cells begin to show typical morphology?

Answer 9

late blast cells

Question 10

describe how the location of hematopoiesis changes over time

Answer 10

1-2 weeks- yolk sac fetus- liver and spleen after birth- long bones, vertebrae, ribs, and pelvis 15-20- long bone activity fades

Question 11

describe cellularity

Answer 11

cellularity describes the percentage of bone marrow occupied by hematopoietic cells. cellularity should decrease with age as fat cells increase

Question 12

extramedullary hematopoiesis

Answer 12

when the liver and spleen reassume hematopoietic function in times of crisis

Question 13

aspirates

Answer 13

sample of bone marrow for study

Question 14

difference between red and yellow marrow

Answer 14

red- young, high cellularity. yellow- older, low cellularity, high fat

Question 15

vascular vs hematopoietic compartments

Answer 15

vascular- sinuses; hematopoietic- develping cells and reticular CT)

Question 16

how does the distribution of developing RBCs vs granuloytes differ in bone marrows?

Answer 16

RBCs- close to sinus surrounding macrophage. granulocytes- farther away

Question 17

how long does erythropoiesis take?

Answer 17

7 days

Question 18

what is the earliest erythrocytic precursor? how can you tell it apart?

Answer 18

reticulocyte. presence of nuclei

Question 19

how long does granulopoiesis take?

Answer 19

14 days

Question 20

describe where to find megakaryocytes in bone marrow

Answer 20

next to venus sinuses. they use dynein motors to extend their processes out