Peripheral blood and hematopoiesis Flashcards by Nathan Plaskett

What is the main difference between stem cells and progenitor cells?

Stem cells are capable of replication AND DIFFERENTIATION at the same time (i.e. making another of its self, and a specialized cell).

Progenitor cells do NOT engage in self-replication, i.e. both the progeny of progenitor cells are DIFFERENTIATING CELLS.

How well did you know this?

Not at all

Perfectly

Describe the chronology and location of hematopoietic tissue

) Early embryo (0-3 months): YOLK SAC
) Second trimester (3-6 months): Liver & spleen
) Third trimester (6-9 months/birth): Bone marrow

How well did you know this?

Not at all

Perfectly

Why is it difficult to to distinguish stem and progenitor cells?

Because they are not morphologically distinct and resemble LYMPHOCYTES.

How well did you know this?

Not at all

Perfectly

Progenitor cells for blood cells are often called _______, and fall into four main categories. Name and describe them.

Progenitor cells, aka COLONY FORMING UNITS (CFUs):

) Erythroid lineage (CFU-E):
) Thrombocytic lineage (CFU-Meg):
) Granulocyte-monocyte lineage (CFU-GM):
) Lymphoid lineage (CFU-L):

How well did you know this?

Not at all

Perfectly

List the general progression of hematopoietic differentiation

Stem cell (not distinguishable) –> Progenitor cell (not distinguishable) –> Precursor cell/blast (distinguishable) –> Mature cell

How well did you know this?

Not at all

Perfectly

Hematopoiesis depends on the _______ or ________, which is largely created by what?

Microenvironment or Niche, which is largely created by endocrine factors, and factors released by local cells and ECM of the hematopoietic organs.

How well did you know this?

Not at all

Perfectly

Hematopoietic growth factors are often called what?

Colony stimulating factors (CSF)

How well did you know this?

Not at all

Perfectly

What are the main contents of bone marrow?

) Reticular connective tissue stroma (bed)
) Hemopoietic cords or islands of cells
) Sinusoidal capillaries

How well did you know this?

Not at all

Perfectly

Describe the stroma of bone marrow

A meshwork of specialized fibroblastic cells called stromal cells (aka reticular cells or adventitial cells). Also contains a web of reticular fibers supporting the hemopoietic cells and macrophages.

How well did you know this?

Not at all

Perfectly

What does the hematopoietic niche of bone marrow include (3)?

Stroma, osteoblasts, and megakaryocytes (precursors to platelets).

How well did you know this?

Not at all

Perfectly

What are the internal cellular changes that are undergone during erythropoiesis?5.

) Cell and nuclear volumes decrease.
) NUCLEOLI diminish in size and disappear.
) Chromatin continually condenses and nucleus shrinks and then eventually disappears.
) Decrease in polyribosomes (basophilia = less blue).
) Increase in hemoglobin (highly eosinophilic = red).
) Mitochondria and other organelles gradually disappear.

How well did you know this?

Not at all

Perfectly

What are the six stages of cellular development in erythropoiesis?

1.) Proerythroblast –> 2.) Basophilic erythroblast –> 3.) Polychromatophilic erythroblast –> 4.) Orthochromatophilic eryhtroblast (normoblast) –> 5.) Reticulocyte (lacks nuclei, but has RNA) –> 6.) Erythrocyte

How well did you know this?

Not at all

Perfectly

What does increased reticulocyte count in a blood test indicate?

Destruction or decrease in number of erythrocytes. Indicates hemorrhage, blood loss, or anemia.

How well did you know this?

Not at all

Perfectly

Give the generalized steps for a cell undergoing Granulocytopoiesis (Granular leukocyte formation)

Myeloblast –> Promyelocyte –[neutrophilic, eosinophilic, or basophilic]–> myelocyte –> metamyelocyte –> stab cell –> Mature: a.) neutrophil b.) eosinophil c.) basophil

How well did you know this?

Not at all

Perfectly

List the cell stages of thrombopoiesis (platelet formation)

Megakaryoblast –> Promegakaryocyte –> Megakaryocyte –> Platelets

How well did you know this?

Not at all

Perfectly

How does the blast cell in thrombopoiesis resemble that of the other blast cells?

Non-condensed chromatin and nucleoli.

How well did you know this?

Not at all

Perfectly

What is the percent composition of plasma (3 things)

) 92% Water
) 7% Protein
) 1% Other solutes

How well did you know this?

Not at all

Perfectly

What are the “formed elements” circulating in plasma

Erythrocytes, leukocytes, and platelets.

How well did you know this?

Not at all

Perfectly

What percent of plasma is protein? What are the proteins contained within (4)?

7% protein:

) Albumins 58%
) Globulins 37%
) Fibrinogen 4%
) Regulatory proteins 1%

Define serum. What are the major differences between serum and plasma?

Serum is the yellow fluid remaining after blood has clotted. It is similar to plasma, BUT LACKS FIBRINOGEN AND CLOTTING FACTORS.

What do Romanovsky stains contain? What are they used for?

Methylene blue, azure dyes, and eosin. They are used to identify blood cells.

What is the volume of blood an average adult has in circulation?

5 liters

What is a smear preparation?

FIND OUT!

What is the most abundant formed element in blood? What is their form/function? What is the point of their shape/form?

Erythrocytes (RBC’s): Specialized to transport oxygen. They are anucleate (no nucleus), biconcave cells with an average lifespan of 120 days. Their BICONCAVE SHAPE helps to maximize surface-to-volume ratio in order to facilitate OXYGEN EXCHANGE.

What helps to maintain the biconcave shape of erythrocytes?

The inner-surface membrane proteins, including SPECTRIN. Dimers of which form a lattice bound to underlying actin filaments and ANKYRIN, which anchors the lattice to glycophorins and band 3 (?) proteins.

What is the metabolic process of RBC's? Why?

Anaerobic glycolysis because they lack MITOCHONDRIA.

What can RBC's do about defective proteins? Why?

Nothing. They cannot replace defective proteins because they lack a NUCLEUS.

Name and describe the two main subdivisions of leukocytes and their respective subdivisions? What is/are their main morphologic difference(s)? Concentrate on appearance of GRANULES and NUCLEUS!!!

1. ) Agranulocytes: NON-SEGMENTED NUCLEI. a. ) Lymphocytes: *DARK ROUND NUCLEUS* with very little cytoplasm. b. ) Monocytes: *INDENTED NUCLEUS* with more cytoplasm. 2. ) Granulocytes: SEGEMENTED NUCLEI. a. ) Neutrophils: Salmon pink/lilac granules that are small and difficult to see. *NUCLEUS has 3-5 lobes* b. ) Eosinophils: Intensely red/orange. *BILOBED NUCLEUS* c. ) Basophils: Blue granules which *OBSCURE THE NUCLEUS*

What are the two classes granules possessed by granulocytes?

1. ) Azurophilic (primary) granules | 2. ) Specific (secondary) granules: Specific to a PARTICULAR TYPE of granulocyte.

What type of granule(s) do neutrophils possess and what is their function?

1. ) Faint pink-lilac SPECIFIC granules: Contain antibacterial compounds for EXOCYTOSIS at sites of bacterial infection. 2. ) Azurophilic (purple) granules: Correspond to LYSOSOMES specialized for killing ingested bacteria.

What are the characteristics and purpose of the granules contained within eosinophils?

They contain eosinophilic granules with a BASIC PROTEIN that has a toxic effect against WORMS AND PARASITES.

Describe the the granules within BASOPHILS: What they contain and what they do.

Basophilic granules that contain HISTAMINE (increases vascular permeability) and HEPARIN (inhibits blood coagulation).

1. ) What are the most abundant agranulocyte? 2. ) What is their purpose? 3. ) What are the major classes? 4. ) What are general morphologic characteristics?

1. ) Lymphocytes 2. ) Central role in immunity 3. ) B Lymphocytes, T Lymphocytes, Natural killer cells. 4. ) Spheroid or slightly indented nucleus with relatively small amount of cytoplasm.

1. ) What class of cells are MONOCYTES? 2. ) What are they precursors to? 3. ) What are general morphologic characteristics of monocytes?

1. ) Agranulocytes 2. ) Macrophages, osteoclasts, microglia, and other cells of the MONONUCLEAR PHAGOCYTE SYSTEM. 3. ) Larger, more deeply indented nucleus, and more cytoplasm than a lymphocyte.

1. ) Describe the structure and function of platelets. | 2. ) What do they release?

Non-nucleated, membrane enclosed fragments of cytoplasm derived from MEGAKARYOCYTES in bone marrow. They are DISC-LIKE and often CLUMPED in blood smears. Major function is to promote blood coagulation by releasing contents of ALPHA and DELTA GRANULES.

Describe the two main regions of platelets

1. ) Hyalomere region: Peripherally situated LIGHT BLUE region of ACTIN FILAMENTS and MICROTUBULES for maintaining shape. Open canalicular system (???) for rapid degranulation. 2. ) Granulomere region: Centrally located PURPLE region of dense alpha and delta granules which contain substances that promote COAGULATION.

Mnemonic for WBC's?

Never Let Monkeys Eat Bananas --> Neutrophils Lymphocytes Monocytes Eosinophils Basophils

What cells resemble coffee beans on electron microscopy?

Eosinophils

Where will and won't you find mast cells and basophils.

You won't see a mast cell inside the blood vessel, and you won't see a basophil outside the blood vessel?

List the chronologic lineage for granulocytes (7)

1.) MYELOID STEM CELL --> 2.) Progenitor cell --> 3.) Myeloblast --> 4.) Promyelocyte --> 5.) Eosin, Baso, Neut MYELOCYTE --> 6.) Eos, Baso, Neut, Metamyelocyte --> 7.) Eosiniphil, Basophil, Neutrophil. p.252

List the chronologic lineage of platelets (Thrombopoiesis) - (6)

1. ) MYELOID STEM CELL --> 2.) Progenitor cell --> 3.) Megakaryoblast --> 4.) Promegakaryocyte [thrombopoietin] --> 5.) Megakaryocyte [thrombopoietin] --> 6.) Platelets p. 252

List the chronologic lineage for erythropoiesis (8)

1.) MYELOID STEM CELL --> 2.) Progenitor cell --> 3.) Proerythroblast --> 4.) Early or basophilic erythroblast --> 5.) Polychromatophilic erythroblast --> 6.) Orthochromatic erythroblast --NUCLEUS EJECTED--> 7.) Reticulocyte --> 8.) Erythrocyte

During which stage of erythropoiesis is the nucleus ejected?

Orthochromatophilic erythropoiesis

What nucleotides do reticulocytes contain?

RNA, but no DNA

At which stage in granulocyte formation do the nonspecific granulocytes appear? Specific?

``` Nonspecific = promyelocyte Specific = Baso, eosin, neutro MYELOCYTE ```

1. ) During what stage of granulopoiesis do azurophilic granules (blue) appear? 2. ) Specific granules?

p. 257 1. ) Promyelocyte 2. ) Myelocyte