hematopoiesis

mayo MLS heme I

Chromatin

DNA and proteins in the nucleus, condenses to form chromosomes during cell division

Euchromatin

Loosely packed chromatin, active in transcription

Heterochromatin

Tightly packed chromatin, inactive in transcription

Endoplasmic reticulum

Organelle for protein modification and folding

Golgi apparatus

Organelle for protein modification and packaging for export

Lysosome

Organelle for intracellular digestion

Microfilaments

Actin filaments for cell structure and muscle contractions

Microtubules

Tubular structures for cell shape and intracellular movement

Mitochondria

Organelles for ATP production through oxidative phosphorylation

Nuclear envelope

Double membrane separating the nucleus from the cytoplasm

Nucleolus

Site in the nucleus for ribosome subunit production

Plasma membrane

Cell membrane composed of a lipid bilayer with embedded proteins

Hematopoiesis

Process of blood cell production and maturation

Differentiation

Process of cell specialization for specific functions

Commitment

Stage where a cell must differentiate into a specific lineage

Maturation

Cell development to acquire all characteristics

Hematopoietic stem cells

Cells capable of forming all blood cell types

Progenitor cell

Intermediate cell between stem and precursor cells

Pluripotent hematopoietic stem cells

Cells able to differentiate into any blood cell type

Cytokines/growth factors

Signaling molecules regulating cell activities and proliferation

Apoptosis

Programmed cell death

Erythropoiesis

Process of red blood cell formation GF= erythropoietin

Granulopoiesis

Formation of granulocytes like neutrophils, eosinophils, and basophils GF=IL-3

Monopoiesis

Formation of monocytes GF= IL-3

Megakaryopoiesis

Process of platelet formation GF= thrombopoietin

Lymphopoiesis

Formation of lymphocytes, many GFs

Erythropoietin, IL-3, Thrombopoietin

Growth factors essential for specific blood cell maturation

Hematopoietic microenvironment

Cellular and extracellular components supporting blood cell development

List where cytokines are produced.

1. bone marrow or hematopoietic microenvironment by stromal cells

2. erythropoietin in kidneys, transported to marrow

stromal cells

1. adipose tissue, endothelial cells, fibroblasts, T cells, macrophages

2. produce growth factors and components of ECM

extracellular matrix

1. made of collagen, glycoproteins, and glycosaminoglycans

2. provides structural support, plays a role in progenitor cells to stroma binding, helps cell-cell interactions, binds and localizes cytokines

RBC differentiation

myeloid stem cell → pronormoblast → basophilic normoblast → polychromatophilic normoblast → orthochromic normoblast → polychromatic erythrocyte → erythrocyte

basophil differentiation

myeloid → myeloblast → promyelocyte → immature basophil → basophil

eosinophil differentiation

myeloid → myeloblast → promyelocyte → immature eosinophil → eosinophil

neutrophil differentiation

myeloid → myeloblast → promyelocyte → myelocyte → metamyelocyte → band neutrophil → segmented neutrophil

monocyte differentiation

myeloid → immature monocyte → monocyte → macrophage

granulocyte differentiation

1. derived from CFU-GEMM and CFU-GM

2. G-CSF promotes granulocyte differentiation

monocyte differentiation

1. derived from CFU-GEMM and CFU-GM

2. M-CSF promotes monocyte differentiation

platelet differentiation

1. CFU-GEMM → CFU-Mk (megakaryocyte proliferator)

   myeloid → megakaryocyte → platelets

B cell differentiation

1. lymphoid → pre-B → b lymphoblast → b cell → plasma cell

T cell differentiation

lymphoid → pre T → t lymphoblast → T cell

prophase

nucleus disappears, chromosomes visible

metaphase

chromosomes aligned along cell center, microtubules reach chromosomes

anaphase

microtubules separate sister chromatids to opposite poles

telophase

nuclear membranes assemble around daughter nulcei, spindle disappears