HEMA LEC HEMATOPOIESIS PRELIM OH MY GOD THIS IS BAD TO STUDY GOOD LUCK TO WHOEVER USES THIS I WISH YOU THE BEST OF LUCK

Cells

Structural units that constitute living organisms containing specialized functions and the components necessary to perform and perpetuate these functions.

Three Basic Parts of Most Cells

The structural organization of most cells consisting of unit membranes, cytoplasm, and a nucleus.

Cell Membrane

A semipermeable outer boundary separating the cellular components from their surrounding environments.

Cell Membrane Functions

Restricting/facilitating substance interchange, detecting hormonal signals for cell recognition, and hosting surface identity markers.

Fluid Mosaic Model

The resilient and elastic membrane structure described as globular proteins floating in a lipid bilayer.

Nucleus Components

The three key parts composing the cell control center: chromatin, nuclear envelope, and nucleoli.

Nucleus

The largest organelle and control center of the cell, composed largely of DNA; serves as the site of DNA replication and transcription.

Cytosol

The homogenous, continuous, aqueous solution in which cellular organelles join and function.

G1 Checkpoint

The cell cycle checkpoint that monitors cell size, nutrients, growth factors, and DNA damage before allowing progression to the S phase.

G2 Checkpoint

The cell cycle checkpoint that verifies cell size and DNA replication before allowing mitotic progression.

Spindle Assembly Checkpoint

The mitotic checkpoint that checks for chromosome attachment to the spindle during metaphase.

Apoptosis

Orderly, programmed cell death characterized by cell shrinkage, membrane blebbing, nuclear breakdown, and macrophage clearance without inflammation.

Necrosis

Accidental cell death where the cell membrane ruptures, releasing non-functional organelles and content, causing tissue inflammation.

Hematopoiesis

A continuous, regulated process of blood cell production that includes cell renewal, proliferation, differentiation, and maturation.

Primitive Hematopoiesis

The stage of blood cell production occurring during the fetal embryonic yolk sac (mesoblastic) stage.

Definitive Hematopoiesis

The continuous stage of blood cell production beginning with the fetal liver stage and continuing through adult life.

Fetal Hematopoietic Phases

The three developmentally regulated, overlapping phases of fetal blood cell production: mesoblastic, hepatic, and medullary.

Mesoblastic Phase

Fetal yolk sac phase of hematopoiesis beginning around the 19th day after fertilization.

AGM Region

The aorta-gonad-mesonephros region where early fetal progenitor cells arise before migrating to embryonic yolk sac blood islands.

Primitive Erythroblasts

The developing cells in the embryonic yolk sac blood islands that produce primitive embryonic hemoglobins.

Portland Hemoglobin

Embryonic primitive hemoglobin structurally designated as ζ2γ2 (zeta2 gamma2).

Gower I Hemoglobin

Embryonic primitive hemoglobin structurally designated as ζ2ε2 (zeta2 epsilon2).

Gower II Hemoglobin

Embryonic primitive hemoglobin structurally designated as α2ε2 (alpha2 epsilon2).

Hepatic Phase

Fetal hematopoiesis phase starting around 4 to 5 gestational weeks, representing the start of definitive hematopoiesis.

Liver

The major anatomical site of active fetal blood cell production during the hepatic phase.

Thymus

serves as the primary lymphoid organ for T-lymphocyte maturation during fetal development.

spleen and kidney

act as anatomical sites of B-lymphocyte formation during the hepatic phase.

Hb F, Hb A, and Hb A2.

The hemoglobins produced during fetal hepatic development

Medullary Phase

Fetal myeloid phase starting around the 5th month of gestation where blood production transitions to the bone marrow cavity.

Medullary Phase Regulatory Cytokines

The key humoral factors regulating bone marrow hematopoiesis in the fetus: EPO, G-CSF, and GM-CSF.

Hb F, Hb A2 , and Adult Hb

The hemoglobins characteristic of medullary development:

Adult Hematopoietic Organs

The specialized tissues where blood cells proliferate and mature: bone marrow, thymus, lymph nodes, spleen, GALT, and liver.

Primary Lymphoid Tissue

Anatomical compartments where lymphocytes undergo antigen-independent maturation: the bone marrow and thymus.

Secondary Lymphoid Tissue

Anatomical compartments where lymphocytes undergo antigen-dependent activation: lymph nodes, spleen, and GALT.

Bone Marrow

The specialized tissue located within the cavities of cortical bones.

Red Marrow

The hematopoietically active portion of the bone marrow.

Yellow Marrow

The hematopoietically inactive bone marrow tissue consisting primarily of adipocytes (fat cells).

Infant Marrow State

A developmental state where bone marrow cavities consist almost entirely of active red marrow.

Retrogression

The process between ages 5 and 7 where adipose tissue gradually replaces red active marrow in long bone cavities.

Spleen

The largest lymphoid organ in the body; acts as an indiscriminate filter of the circulating blood.

Splenic Tissue Types

The structural compartments dividing the splenic parenchyma: white pulp, red pulp, and the marginal zone.

Culling

The splenic filtration function involving the destruction and removal of senescent, aged red blood cells.

Pitting

The splenic filtration function where macrophage enzymes pluck intracellular inclusions from circulating RBCs without cell destruction.

Lymph

The fluid portion of blood escaping into connective tissue characterized by low protein and the complete absence of RBCs.

Lymph Nodes

Bean-shaped organs arranged in chains along lymphatic vessels that filter lymph and process immunoglobulins.

Cortex of Lymph Node

The outer lymph node region containing follicles and germinal centers dedicated to B cell proliferation.

Medulla of Lymph Node

The inner lymph node region consisting of B cells and plasma cells.

Paracortex of Lymph Node

The intermediate lymph node region between the cortex and medulla populated by T cells and macrophages.

Lymph Node Functions

The three primary purposes of lymph nodes: lymphocyte formation, immunoglobulin processing, and debris/bacterial filtration.

Thymus Structure

A bilobed lymphoid organ in the upper anterior mediastinum divided into a cortex and medulla, populated by lymphocytes, mesenchymal, and reticular cells.

Liver Disease Role

Organ that resumes extramedullary hematopoiesis during severe hemolytic anemias, bone marrow shutdown, or metabolic storage diseases.

Till and McCulloch

The scientists whose landmark transplantation studies established the foundation for modern Stem Cell Theory.

Undifferentiated Stem Cells

Morphologically unrecognizable hematopoietic cells capable of self-renewal and multilineage differentiation.

Monophyletic Theory

The theory suggesting that all blood cell lineages originate from a single progenitor cell called a pluripotential stem cell.

Polyphyletic Theory

The theory suggesting that each of the distinct blood cell lineages derives from its own unique, dedicated stem cell.

Stem Cell

A cell characterized by self-renewal capacity, the ability to give rise to differentiated progeny, and reconstitute a lethally irradiated host.

HSC Fates

The three potential outcomes directed at an undifferentiated stem cell: self-renewal, differentiation, or apoptosis.

Maturation Size Trends

The general developmental pattern of blood precursors showing an overall decrease in cell size and decrease in the nuclear-to-cytoplasmic (N:C) ratio.

Nuclear Maturation Changes

The morphological transformations of a developing nucleus: loss of nucleoli, chromatin condensation, nuclear size reduction, and eventual loss.

Cytoplasmic Maturation Changes

The morphological transformations of a developing cytoplasm: decrease in basophilia, increase in relative cytoplasmic proportion, and appearance of specialized granules.

approximately 3 billion cells.

The average daily production of red blood cells in healthy adult bone marrow:

: approximately 2.5 billion cells.

The average daily production of platelets in healthy adult bone marrow

approximately 1.5 billion cells.

The average daily production of granulocytic white blood cells

1 stem cell per 1,000 nucleated bone marrow cells.

The baseline physiological frequency of stem cells: approximately

G0 Phase

The resting phase of the cell cycle where stimulated stem cells go to rest or direct toward terminal differentiation after division.

Earliest Identifiable Human HSC

The specific immunophenotypic profile characterized as CD34+, CD38-, HLA-DRlow, Thy1low, Lin-.

Loss of Stemness Marker

The specific surface marker gain of CD38 and HLA-DR that denotes cell commitment and loss of pluripotency.

Committed Myeloid Progenitor Markers

The co-expression of CD33 and CD38 surface proteins.

Committed Lymphoid Progenitor Markers

The co-expression of CD10 and CD38 surface proteins.

T Lymphoid Progenitor & NK Cell Marker

The surface expression of CD7.

B Lymphoid Progenitor Marker

The surface expression of CD19.

In Vitro Assays

Assays utilizing semisolid media (like methylcellulose) to enumerate colonies like CFU-GEMM, CFU-GM, or BFU-E.

In Vivo Assays

Functional assays requiring the transplantation of hematopoietic cells into syngeneic, lethally irradiated animal recipients.

Cytokines and Growth Factors

Soluble glycoproteins that regulate the cell division, differentiation, maturation, trafficking, and survival of hematopoietic cells.

Positive Cytokines

A regulatory group of factors promoting stem cell division, including IL-1, IL-3, IL-6, IL-9, IL-11, GM-CSF, and Kit ligand.

Negative Cytokines

A regulatory group of factors inhibiting hematopoiesis, including TGF-β, TNF-α, and interferons.

Growth Factor Division Stimulus

The mechanism of division where growth factors decrease precursor transit time from the G0 to G1 phase of the cell cycle.

Kit Ligand (SCF)

An early-acting multilineage cytokine whose receptor on the cell surface is the product of the c-kit gene.

Flt3 (c-fms-like tyrosine kinase)

An early-acting cytokine working earlier than SCF; works synergistically with IL-3, G-CSF, and GM-CSF to promote HSC proliferation.

Interleukins

Soluble proteins first discovered as products of macrophages and T cells that show synergistic interactions and function at low concentrations.

Thrombopoietin (TPO)

The lineage-specific glycoprotein regulator responsible for megakaryopoiesis and platelet production.