Hematopoiesis

False

(True/False) A blood cell with an immature nucleus would have smaller size as seen in Vitamin B12 deficiency anemia.

False

(True/False) Adults have more red marrow than yellow marrow.

True

(True/False) Babies and children have more red marrow activity.

True

(True/False) Blood cells with immature cytoplasm are associated with impaired hemoglobin production as in iron-deficiency anemia.

True

(True/False) Decline in primitive hematopoiesis in the yolk sac is indicated by the presence of developing erythroblasts.

True

(True/False) Hematopoiesis in the AGM region and yolk sac disappear during the hepatic phase.

False

(True/False) In children, the sites of red bone marrow are the flat bones only.

True

(True/False) Inhibition of apoptosis allows uncontrolled proliferation of cells.

False

(True/False) KIT Ligand expression increases in differentiation.

False

(True/False) Mesoblastic phase occurs extravascularly while hepatic phase occurs intravascularly.

False

(True/False) Primitive erythroblasts are the direct precursors of mature RBCs.

True

(True/False) Primitive erythroblasts are transient and do not undergo maturation.

False

(True/False) RBCs are present in the lymph.

True

(True/False) Synchronous hematopoiesis produces normal cells.

False

(True/False) The mesoblastic phase is a definitive hematopoiesis.

True

(True/False) The product produced during hepatic phase is not embryonic hemoglobin.

False

(True/False) When cells do not receive the appropriate cytokines necessary to prevent cell death, necrosis is initiated.

True

(True/False) Yellow marrow can be replaced by red marrow when needed.

True

(True/False) Yolk sac hematopoiesis occurs within developing blood vessels.

Medullary phase

Cells at various maturation stages can be seen in this phase.

Erythroblasts

Cells found surrounding iron-laden macrophages.

Colony-forming units

Cells that are capable of giving rise to multiple lineages of blood cells.

Stromal Cells

Cells that originate from mesenchymal cells that migrate into the cavity of the bone and includes endothelial cells, fat cells, macrophages, lymphocytes, osteoblasts, osteoclasts, and fibroblasts.

Angioblasts

Cells that surround the cavity of the yolk sac and eventually form blood vessels.

Primitive erythroblast

Considered as the first primitive cell to be produced originated from the mesoderm.

KIT

A receptor-type tyrosine-protein kinase that is expressed on HSCs and is down regulated with differentiation.

Monophyletic Theory

A theory on blood formation which suggests that all blood cells are derived from a single progenitor stem cell called the pluripotent hematopoietic stem cell.

Polyphyletic Theory

A theory on blood formation which suggests that each of the blood cell lineages is derived from its own unique stem cell.

Asynchronous

A type of hematopoiesis where the nucleus and cytoplasm do not develop together.

CD33 and CD38

Acquisition of these surface markers are seen on committed myeloid progenitors

Hematopoiesis

Continuous regulated process of blood cell production.

Extravascular cords

Cords located in spaces between the vascular sinuses and are supported by trabeculae of spongy bone.

B cell

The developing kidneys and spleen are associated with the production of what cell?

IL-10

The primary cell source of this growth factor are the CD4+, Th2 T Cells, CD8+ T cells and macrophages and they function to inhibit cytokine production and inhibit macrophages.

Extravascular cords

The red marrow is composed of hematopoietic cells and macrophages arranged in?

Erythroblasts

These cells develop in small clusters, and the more mature forms are located adjacent to the outer surfaces of the vascular sinuses.

Erythropoietin

Hormone that stimulates RBC production

Niche

Also known as "hematopoietic inductive microenvironment"

Cytokines

Also known as hematopoietic growth factors.

CD38 and HLA-DR

Are associated with the loss of "stemness".

Hepatic Phase

Begins at 5-7 gestational weeks and is characterized by recognizable clusters of developing erythroblasts, granulocytes, and monocytes colonizing the fetal liver, thymus, spleen, placenta and ultimately the bone marrow.

KIT Ligand

Binding of this growth factor triggers cell proliferation and stimulates growth viability and adhesion.

Periosteal arteries

Blood vessel that provides nutrients for the osseous bone and the marrow.

Nutrient artery

Blood vessel that supplies blood only to the marrow

Endothelial cells

Broad flat cells that form a single continuous layer along the inner surface of blood vessels.

GM-CSF

CSF that targets the granulocytic-monocytic cell line.

Hypersplenism

Enlargement of the spleen resulting in some degree of pancytopenia despite the presence of a hyperactive bone marrow.

Splenomegaly

Enlargement of the spleen that may be caused by chronic leukemias, inherited membrane or enzyme defects in RBCs and more.

CD10 and CD38

Expression of these surface markers are found on committed lymphoid progenitors.

Thymus

First fully developed organ in the fetus associated with T cell production

Mesoderm

Germ layer that gives rise to specialized tissue types.

EPO

Growth factor produced in the kidney that stimulates proliferation of erythroid progenitor

Interferon alpha

Growth factor that has an antiviral biological function and enhances MHC expression

IL-3

Growth factor that regulates blood cell production by controlling the production, differentiation, and function of granulocytes and macrophages.

Red marrow

Hematopoietically active marrow containing blood cells and their progenitors.

Yellow marrow

Hematopoietically inactive marrow consisting of adipocytes with undifferentiated mesenchymal cells and macrophages.

Medullary Phase

In this phase, measurable levels of erythropoietin, G-CSF, GM-CSF, and Hemoglobins A and F are detected.

Stem Cell Factor

KIT Ligand is also known as?

Adipocytes

Large cells with a single fat vacuole

GPA, CD71

Lineage specific markers of erythroid progenitors.

CD61, CD41

Lineage specific markers of megakaryocyte progenitors.

Bone marrow

Main site of medullary phase.

yolk sac

Major site of adult blood formation in the embryo.

Liver

Major site of blood cell production during the second trimester of fetal development

Liver

Major site of hematopoiesis during the second trimester of fetal life.

Yolk Sac Phase

Mesoblastic phase is also known as the?

Hemoglobin F

Most predominant type of hemoglobin during hepatic phase.

FLT3 Ligand

Multilineage growth factor that stimulates primitive progenitor cells and works with SCF.

3:1

Myeloid:Erythroid ratio in the bone marrow.

19th

On what day of embryonic development after fertilization does hematopoiesis begin?

Kidney

Organ responsible for production of erythropoietin.

Thymus

Organ whose function is to serve as a "waiting zone" and is densely populated with progenitor T Cells.

Hepatic phase

Phase where production of megakaryocytes begin.

granulocytic cell line

Primary target of G-CSF

Common myeloid progenitor

Progenitor cell that proliferates and differentiates into individual granulocytic, erythrocytic, monocytic, and megakaryocytic lineages.

Common lymphoid progenitor

Progenitor cells which proliferate and differentiate into T, B, and natural killer lymphocyte and dendritic lineages.

1:1000

Ratio of HSC to nucleated blood cells in the bone marrow.

yolk sac

Site of mesoblastic stage

Cytokines

Specific glycoproteins that regulate the proliferation, differentiation, and maturation of hematopoietic precursor cells.

White pulp

Splenic tissue that consists of scattered follicles with germinal centers containing lymphocytes, macrophages, and dendritic cells.

Nutrient and periosteal arteries

Supplies nutrient and oxygen requirements of the marrow.

CD7

Surface marker expressed on T-lymphoid progenitor cells and natural killer cells

CD19

Surface marker seen on B-lymphoid progenitors.

Till and McCulloch

They proposed that hematopoiesis is a random process whereby HSC randomly commits to self-renewal or differentiation.

GM-CSF

This CSF also works synergistically with IL-3 to enhance megakaryocyte colony formation.

Hematopoietic Stem Cell

This cell is capable of self-renewal and directed differentiation into all required cell lines.

Retrogression

This happens at 5-7 years of age when the red marrow is replaced by yellow marrow.

Medullary phase

This hematopoietic phase begins at 5th month of gestation where bones start to develop.

Hematopoiesis

This process includes cell renewal, proliferation, differentiation and maturation.

Self renewal, Differentiation, Apoptosis

Three possible fates of HSCs.

Bone marrow

Tissue located within the cavities of the cortical bones.

Primitive lymphoid cells

Type of cells that initially populate the thymus.

Medullary

Type of hematopoiesis where blood cell production occurs in the inner cavity of the bone marrow.

Extramedullary

Type of hematopoiesis where blood cell production occurs in the liver, spleen, or thymus.

Synchronous

Type of hematopoiesis where the nucleus and cytoplasm grow together at the same rate.

Aorta-gonad-mesonephros region

Where the cells of mesodermal origin migrate to give rise to HSCs for definitive hematopoiesis.