hemopoiesis and blood - histology on the flyhistologyonthefly.com/pdfs/blood08.pdf · o...

Hemopoiesis and

Blood

Blood

• Cellso Erythrocyteso Leukocyteso Thrombocytes

• Functiono Transport nutrients and wastes throughout the bloodstream, fight foreign

antigens and blood coagulation.

• Locationo Located in blood vessels throughout the body.

• Structureo Erythrocytes

4.2-6.2 million per cubic mm Biconcave shape Anucleated

o Leukocytes 5-10,000 per cubic mm Granulocytic

• Specific granuleso Provide function of specific white blood cell

• Azurophilic granuleso Lysosomal properties

• Neutrophilso 60%-70% of populationo Destroy bacteriao Multilobed nucleus

• Eosinophilso < 4% of populationo Phagocytose antigen-antibody complexes and kill

parasitic invaderso Bilobed nucleuso Large, red specific granules

• Basophilso < 1% of the populationo Two or more irregular lobed nucleus

Obscured by large specific granules Agranulocytic

• Lymphocyteso 20%-25% of the populationo Spherical nucleuso Few granules in cytoplasm

• Monocyteso 3%-8% of the populationo Kidney shaped nucleus, acentrico Few granules in cytoplasm

o Thrombocytes Anucleated Dislike cell fragments Hyalomere

• Peripheral clear region Granulomere

• Central darker region

• Video recordingo Blood

• Microscope imageso See above

Red Bone Marrow

• Functiono Vascular connective tissue responsible for the production of formed

elements.

• Locationo Located in the medullary cavity of long bones and within trabeculae of

spongy bone.

• Maturation Lineage of Formed Elementso Erythropoiesis

Myeloid Stem Cell Proerythroblast

• Large cell• “Lacy” chromatin• Nucleoli• Basophilic cytoplasm

o Due to synthesis of hemoglobin Basophilic erythroblast

• More basophilic• Condensed nucleus

Polychromatophilic erythroblast• Regions of basophilia and acidophilia

Orthochromatophilic erythroblast• Uniform acidophilic cytoplasm

Reticulocyte• Ejection of nucleus• 1% of circulating blood cells

Erythrocyte• Matured reticulocytes• See previous study guide topic

o Leukopoiesis Granulocytes

• Myeloblasto Finely dispersed chromatino Faint nucleoli

• Promyelocyteo Basophilic cytoplasmo Azurophilic granules

• Myelocyteo Differentiation startso Increase in granules

• Metamyeloctye

o Further differentiation o Condensation of nucleus

• Stab/Band cell o Elongated nucleus

• Neutrophil, eosinophil, basophil, monocyte o See next study guide topic

Lymphoid Stem Cell • Lymphoblast • Prolymphocyte • Lymphocyte

o See previous study guide topic

o Thrombopoiesis

Myeloid Stem Cell Megakaryoblast

• Large, rare • Basophilic cytoplasm

Megakaryocyte • Larger • Cytoplasm is less basophilic • Diassociate into thrombocytes

Thromobocytes • See previous study guide topic

• Structure of Bone Marrow

o Endosteum o Sinusoids

Lined with endothelial cells o Islands of hemopoietic cells

Blood cells in various stages of maturation o Macrophages

Acute Granulocytic Leukemia (Acute Myeloblastic Leukemia)

• Etiology o Cancer of the bone marrow or blood o Most adult cancer o Abnormal rapid growth of immature (acute) white blood cells

Myeloid stem cell

• Pathological Features o Increased amount (~10x) immature white blood cells in a peripheral smear

Immature white bloods cells should not be found in the blood Mostly promyelocytes

• Hypergranular • Multiple nucleoli • Fine nuclear chromatin • Scant to moderate amount of cytoplasm

o Auer rods Red-staining rod like structures Clumps of azurophilic granules

o Decreased amounts of other cells (i.e. thrombocytes) Bone marrow is occupied with making myelocytic cells

• Microscopic images

o 40x

Chronic Lymphocytic Leukemia

• Etiology o Cancer of the bone marrow or blood o Abnormal rapid growth of mature lymphocytes

Most common are B-Lymphocytes

• Pathological features o Increased amounts (~10x) of mature lymphocytic cells o Irregular nuclei with clumped chromatin o Smudge cells

Crushed nuclei of lymphocytes due to fragility during preparation o Rieder cells

Lymphocytic cells with nuclear clefts, indentations, and deep grooves

• Microscopic images o 10x o 40x

Sickle Cell Anemia

• Etiology o Autosomal recessive disorder o Abnormal hemoglobin molecules within the beta chain

Substitution of glutamic acid with valine Causes a structural disorder within the red blood cell

• Loss of flexibility • Dysfunction at capillary beds

• Pathological features

o Increased destruction of sickled red blood cells Anemia

o Anisocytosis Unequal sizes of blood cells

o Poikilocytosis Abnormally shaped blood cells

• Microscopic images

o 40x

erythrocytes

neutrophil

eosinophil

basophil

lymphocytes

monocyte

thrombocytes

proerythroblast

orthochromatrophic erythroblast

promyelocyte

myelocyte

stab band cell

megakaryocyte

40x acute granulocytic leukemia

10x chronic lymphocytic leukemia

40x chronic lymphocytic leukemia

40x sickle cell anemia