Hematopoiesis

Question 1

What is hematopoiesis?

Answer 1

Formation of blood cells. Occur in the bone marrow

Question 2

What are the major types of blood cells?

Answer 2

erythrocytes, thrombocytes, leukocytes

Question 3

What do pluripotent hematopoietic stem cells develop into?

Answer 3

erythroblasts, myelobasts, monoblasts, lymphoblasts, megakaryoblasts

Question 4

What is growth factor?

Answer 4

A protein capable of stimulating cellular proliferation and cellular differentiation. Examples: cytokines and hormones

Question 5

What is the regulator involved in every hematopoetic pathway except lymphocytes?

Answer 5

GM-CSF

Question 6

What are the major regulators of cells?

Answer 6

TPO, EPO, GM-CSF, G-CSF

Question 7

What is thrombopoietin?

Answer 7

regulates myeloid progenitor cells to differentiate to megakaryocytes (thrombocyte-forming cells)

Question 8

What is erythropoietin?

Answer 8

Regulates maturation from a myeloid progenitor cell (erythroid precursor) to become an erythrocyte. Produced in the kidneys (Renal Medulla)

Question 9

Why is EPO regulated by the kidneys?

Answer 9

Operates at low-oxygen tension and participate in the blood filtration.

Question 10

What is G-CSF (Granulocyte Colony-Stimulating Factor, GCSF, or CSF-3)?

Answer 10

Involved in proliferation and maturation of granulocytes, neutrophils and stems cells.

Question 11

what is GM-CSF (Granulocyte-macrophage colony-stimulating factor)?

Answer 11

Cytokine that functions as a white blood cell growth factor. We have medication to stimulate the production of white blood cells following chemotherapy.

Question 12

What is GM-CSF involvement in the immune/inflammatory cascade?

Answer 12

GM-CSF stimulates stem cells to produce granulocytes and monocytes. Monocytes mature into macrophages. Activation of macrophages can increase in their numbers, crucial for fighting infection.

Question 13

What are the two components of blood?

Answer 13

Formed elements: Red blood cells, white blood cells and platelets. Plasma: aqueous medium, containing proteins, small molecules, and ions

Question 14

Describe characteristics of erythrocytes.

Answer 14

Small cells. Diameters: 6.5-8 um. 4-6 million cells/uL. No nucleous, No mitochondria, no ribosomes

Question 15

Describe characteristics of leukocytes.

Answer 15

Classified based on nuclear shape and granule shapes (and types). Larger. Diameters: 12-15 um
Less abundant: 4000-10,000 cells/uL

Question 16

Describe characteristics of neutrophils (PMNs).

Answer 16

Nuclei with 2-5 lobes and fine chromatin threads. Small primary granules and secondary granules. Immature ones are called bands

Question 17

Describe characteristics of eosinophils

Answer 17

Bi-lobed nuclei and numerous large granules (bright red orange)

Question 18

Describe characteristics of basophils

Answer 18

Irregular multi-bobulated nuclei and numerous blue granules. Contain histamine and heparin

Question 19

Describe characteristics of monocytes

Answer 19

(Precursor of macrophage): Large 12-20 um. Kidney shaped nucleus. no granules

Question 20

Describe characteristics of lymphocytes

Answer 20

Smaller (similar to erythrocytes). Spherical nucleus-stains darkly, thin cytoplasm. no granules

Question 21

Describe characteristics of platelets

Answer 21

Small (2-4um). 150,000-450,000 cells/uL. Anucleate cell fragments. Membrane enclosed sacs of cytoplasm.