Hemopoiesis and Organs

Hematopoiesis/hemopoiesis is the production and development of the ______ of the blood.

cellular components

A pluripotent stem cell (PSC/HSC) is capable of ______.

renewal

A pluripotent stem cell (PSC/HSC) gives rise to ______ cells.

Hematopoietic Progenitor Cells (HPCs)

A hematopoietic progenitor cell is derived from one ______ stem cell.

pluripotential

What are the two types of hematopoietic progenitor cells?

Undifferentiated/noncommitted and multipotential/committed

Undifferentiated/noncommitted hematopoietic progenitor cells are also known as ______.

hematopoietic stem cells (HSC)

Multipotential/committed hematopoietic progenitor cells are committed to becoming a ______ cell.

blood

Precursor stem cells are ______ specific. What are the two specificities?

lineage

lymphoid or myeloid

What are the three stages of fetal hematopoiesis?

Mesoblastic --> hepatic --> medullary (myeloid)

The mesoblastic phase of fetal hematopoiesis occurs ______.

extra-embryonically

The mesoblastic phase of fetal hematopoiesis starts about ______ days after fertilization.

19

During this phase, mesodermal cells can migrate to the ______ or the ______ region.

yolk sac, aorta-gonad mesonephros (AGM)

During the mesoblastic phase of fetal hematopoiesis, some cells become ______ in the central cavity of the yolk sac.

erythrocytes (produce hemoglobin)

During the mesoblastic phase of fetal hematopoiesis, some cells become ______ that surround the yolk sac cavity to become blood vessels.

angioblasts

During the mesoblastic phase of hematopoiesis occurs ______.

intravascularly

AGM-region mesodermal cells give rise to ______ that become the permanent source of adult hematopoiesis.

HSC

The hepatic phase of hematopoiesis starts at ______ gestational weeks.

5-7

The hepatic phase consists of recognizable clusters of developing ______, ______,, and ______.

erythroblasts, granulocytes, monocytes

These are found where?

Liver, thymus, spleen, placenta, bone marrow

The hepatic phase is the start of ______ hematopoiesis.

difinitive

The hepatic phase of hematopoiesis occurs extra vascularly, mostly in the ______.

liver

During the hepatic phase, ______ cells start to appear.

lymphoid

The thymus is the major site of ______ cell production, while the kidney/spleen are the major sites of ______ cell production.

T, B

During the hepatic hematopoiesis phase, ______ production starts.

megakaryocyte

What is the major type of hemoglobin present in the hepatic phase?

Fetal hemoglobin (Hgb F)

Where does the medullary/myeloid phase of hematopoiesis take place?

Medulla (inner part of the bone)

During this phase, mesenchymal cells and HSCs in the bone give rise to ______ elements for support and ______ cells.

structural, hematopoietic blood

What is the adult myeloid : erythroid ratio?

3 : 1

The medullary/myeloid phase of hematopoiesis starts at week ______.

24

At this time, ______ begins to take over as the primary organ of hematopoiesis.

bone marrow (BM)

What other elements are present during the medullary/myeloid phase?

Erythropoietin, granulocyte-CSF, GM-CSF, hemoglobin F and A

Cells during the medullary/myeloid phase are in all stages of ______ of all ______.

maturation, lineages

Where does hematopoiesis occur in the mesoblastic fetus?

Yolk sac

Where does hematopoiesis occur in the hepatic fetus?

Liver and spleen

Where does hematopoiesis occur in the medullary/myeloid fetus?

Bone marrow

Where does hematopoiesis occur after birth?

Tibia, femur, lymph nodes, vertebra, sternum, rib

What locations of hematopoiesis die out at adulthood?

Tibi and femur

What are the two types of bone marrow?

Red and yello

Red bone marrow is ______ active.

Hematopoietically

Yellow bone marrow is haematopoietically ______.

inactive

Yellow marrow contains ______.

adipocytes (fat cells)

Between 5-7 years of age, ______ marrow replaces ______ marrow (retrogression).

yellow, red

Yellow marrow can ______ to ______ if needed.

revert back, red marrow

When might this be needed?

Excessive blood loss

What are the stromal cells present in developing bone marrow?

Endothelial cells, adipocytes, macrophages, lymphocytes, osteoblasts, osteoclasts, fibroblasts

Endothelial cells regulate ______ of things entering/leaving the bone marrow.

flow

Adipocytes regulate ______ of marrow in which active hematopoiesis occurs.

volume

Adipocytes secrete ______ to stimulate what?

cytokines, HSC

Macrophages are ______.

phagocytic

Lymphocytes are ______.

white blood cells

Osteoblasts are bone ______ cells.

forming

Osteoclasts are bone ______ cells.

resorbing

Reticular adventitial cells form a ______ lattice for developing cells.

supporting

Extracellular matrix consists of what?

Fibronectin, collagen, laminin, etc.

The fetal liver is involved in ______ development.

hematopoietic

The adult liver synthesizes and stores essential ______.

vitamins/minerals

The adult liver synthesizes essential ______ proteins.

transport

The adult liver allows for the conjugation of ______ to ______ for excretion.

hemoglobin, bilirubin

The adult liver is highly vascularized to gather, transfer, and eliminate substances via the ______.

bile duct

The liver contains ______ cells.

kupffer

In adults, the spleen ______ blood.

filters

What are the substances of the spleen?

White and red pulp, separated by the marginal zone.

The spleen's white pulp contains ______ and free ______.

lymphocytes, macrophages

The spleen's red pulp contains ______ separated by ______.

vascular sinusoids, cords of Billroth

Red pulp has specialized ______.

macrophages

Red pulp has a sponge-like matrix that acts as a ______.

filter

The main function of the adult spleen is the removal of ______.

abnormal/senescent RBCs

This is accomplished through the ______ by the cords of Billroth

culling and pitting

Culling is the _______ of cell parts and pitting is the ______ of inclusions or damaged surface membranes.

phagocytosis, removal

What are some other spleen functions?

Extravascular hemolysis of senescent erythrocytes, storage of platelets

What two functions do the lymph nodes serve?

B- and T-cell activation/proliferation

B-cell activation and proliferation occurs in the ______ of the cortical nodules of the lymph nodes.

germinal center

T-cell activation and proliferation occurs in the ______ of the cortical nodules of the lymph nodes.

paracortex

The lymph nodes serve in initiation of ______.

specific immune response

The lymph nodes also ______ the particulate matter, debris, and bacteria entering via lymph.

filter

The thymus cortex is the ______ for lymphocytes coming from the bone marrow.

"waiting zone"

This means there are no T cell ______.

surface markers

Entry into the thymus medulla depends on the presence of ______.

surface markers (maturation)

The KIT ligand (SCF) is a late acting cytokine in ______ and ______ reproduction.

eosinophil, basophil

The FLT3 ligand promotes proliferation and differentiation of early ______.

HSC

Early-acting interleukins

IL-1/3/6

IL-1/3/6 act on ______ and ______.

HSCs, myeloid progenitors

Erythropoietin (EPO) acts on ______, ______, and ______ to trigger erythropoiesis.

Burst Forming Units (BFU-E), Colony Forming Units (CFU-E), precursors

EPO has ______ progenitors and precursors.

erythroid

EPO is ______ acting.

early and late

EPO synthesis is ______.

renal tubule epithelia

Thrombopoietin (TPO) acts on ______ and ______ precursors to initiate platelet production (megakaryopoiesis).

CFU-Meg, MK

GM-CSF (Colony Stimulating Factor-Granulocytes Monocytes) act on all ______ lineages. This means that it acts on ______.

myeloid (CFU-GEMM)

What are the three fates of HSCs?

Self-renewal, differentiation, apoptosis

What are the cellular markers of an HSC?

CD7/ 10/ 19/ 33/ 34/ 38-HLA-DR

Increased expression of CD38 and HLA-DR = loss of ______.

"stemness"

CD33+ CD38+ = committed ______ progenitors.

myeloid

CD10+ CD38+ = committed ______ progenitors.

lymphoid

CD7+ = ______ progenitors.

T-lymphoid

CD19+ = ______ progenitors.

B-lymphoid

What cell types can develop from the CFU-GEMM hematopoietic progenitor cell?

Granulocytes, erythrocytes, macrophage-monocytes, megakaryocytes

What cell types can develop from the CFU-GM hematopoietic progenitor cell?

Granulocytes, macrophage-monocytes

What cell types can develop from the CFU-Eo hematopoietic progenitor cell?

Eosinophils

What cell types can develop from the CFU-Bas hematopoietic progenitor cell?

Basophils

What cell types can develop from the CFU-Meg hematopoietic progenitor cell?

Megakaryocytes