Hdb Wee 1 Flashcards (Hematopoesis, Cbc, Hemostasis)

Front 1

What does a Coulter Counter measure?

Back 1

Measures just the number of RBCs (# of events) and the Mean Corpuscular Volume (MCV) (average waveform size). All other RBC lab values are calculated (except Hgb, which is measured with a different instrument).

Front 2

What is hematocrit and how is it measured?

Back 2

HCT, or packed cell volume, is the part of the blood volume composed solely of RBCs.

It is calculated by MCV x RBC(#) and is expressed as a percentage of total blood volume.

Front 3

What is mean corpuscular hemoglobin (MCH) and how is it calculated?

Back 3

MCH is average hemoglobin per RBC.

It is calculated by HGB / RBC.

Front 4

What is mean corpuscular hemoglobin concentration (MCHC)?

Back 4

Measured by the Hgb / Hct, MCHC is the average concentration of hemoglobin per RBC. It relates Hgb to the volume of red cells rather than to the whole blood.

Front 5

What is the corrected reticulocyte count? What are reticulocytes?

Back 5

Reticulocytes are immature RBCs. The count is given as a percentage of total RBCs and is normally about 1%. Corrected reticulocyte count takes into account the pt's HCT. It is calculated by retic count (%) x HCT(pt)/HCT(nrml)

Front 6

Describe Cold Agglutinin Disease.

Back 6

Condition of autoantibodies of the IgM class that are large and bind RBCs, tending to aggultinate. The HCT will be artificially low to do a much lower RBC count than is true. The disease can cause chronic hemolytic anemia

Front 7

What is a myeloblast?

Back 7

Earliest direct neutrophil precursor. Not often seen in normal marrow, often only visualized in leukemias.

characterized by a round nucleus that occupies most of the cell, delicate, uncondensed nuclear chromatin, and one or more easily visible nucleoli

Front 8

What is a promyelocyte?

Back 8

The promyelocyte is the earliest neutrophil precursor that is easily visible in the bone marrow. It is a large round cell with a large, round or oval nucleus that occupies most of the cell. The nuclear chromatin is fine and open, maybe a bit coarser than that of a myeloblast, and nucleoli may be present. The nuclear detail may be obscured by abundant coarse, dark red-purple (primary) granules that overlie the nucleus.

Front 9

What is a myelocyte?

Back 9

It is still a large round cell with a round to oval nucleus, but more of the cell is now taken up by cytoplasm. The cytoplasm is paler than that of the promyelocyte and the primary granules begin to disappear. Note the nucleus has moved to one side of the cell and, on the inside surface of the nucleus, is a clear area where a golgi has formed to synthesize new, neutrophilic granules.

Front 10

What is a metamyelocyte?

Back 10

metamyelocyte is an advanced stage of myeloid maturation. It is a bit smaller than a myelocyte and its nucleochromatin is coarse. The nucleus is kidney bean shaped, a prelude to the ultimate segmentation of the nucleus. No nucleoli can be seen. There is more cytoplasm:nucleus and neutrophilic granules are appearing.

Front 11

What is a band (neutrophil development)?

Back 11

The band is an almost-fully-matured neutrophil. It has a horseshoe shaped nucleus that has not begun to pinch off segments. Its nuclear chromatin is very coarse and mature. The cytoplasm is mature and contains neutrophilic granules. It may be seen in the peripheral blood in infection or inflammation.

Front 12

What is a neutrophil and where does it get its name from?

Back 12

Most abundant WBC in blood (40-70%). It's nucleus normally has 3-4 lobes. It is a granulocyte that functions as part of the innate immune system.

It's namesake is it's granules poor staining with H/E, thus neutral stain = neutrophil.

Front 13

Contrast eosinophils and basophils

Back 13

The eosinophil is a granulocyte with a nucleus that us usually segmented into two lobes, sometimes three. It has beautiful pinkish red granules that have an alkaline pH and thus bind the acidic dye eosin.
The basophil is a granulocyte whose granules are acidic in pH and take up the basic dyes hematoxylin or methylene blue. Its nucleus is typically segmented into 2-3 broad, flat appearing lobes but is usually obscurred by the spectacular bluish-black granules.
Eosinophils usually account for 0-8% of white cells, basophils for 0-2%.

Front 14

what is toxic granulation?

Back 14

Toxic granulation refers to the presence of abundant dark, primary granules in the cytoplasm of the neutrophil. This occurs in severe bacterial infection and may represent disordered cytoplasmic maturation in the face of heightened demand for neutrophils in the peripheral blood.

Front 15

What is toxic valuolization?

Back 15

Toxic vacuolization occurs when a neutrophil, in killing engulfed bacteria with its granular enzymes, accidentally begins to dissolve itself with the same enzymes, forming so-called autophagic vacuoles. This may be seen in severe bacterial infection.

Front 16

What are Dohle Bodies?

Back 16

Döhle bodies are pale blue, irregularly shaped cytoplasmic inclusions that consist of aggregated ribosomes and/or rough endoplasmic reticulum. They may be seen in severe bacterial infection, inflammation or the inherited May-Heggelin anomoly in which case they are aggregates of nonmuscle myosin heavy chain IIA

Front 17

What are Auer Rods?

Back 17

Auer rods can be seen in the leukemic blasts of acute myeloid leukemia (FAB type M2 or M3). They are aggregates of granular material that form elongated needles composed of fused lysosomes.

Front 18

What is a Small Lymphocyte?

Back 18

A small lymphocyte is characterized by a round nucleus with very coarse, condensed chromatin, without visible nucleoli. The nucleus is just about the same size as a normal size red blood cell and can be used as an internal measuring device in assessing red cell size. Cytoplasm is blue and generally scanty, typically visible as a rim on one side of the nucleus.

Front 19

What is an Aytpical (or Reactive) Lymphocyte?

Back 19

Atypical or reactive lymphocytes are larger than small lymphocytes, have abundant pale blue cytoplasm without granules, and a large round to oval nucleus with condensed chromatin. The edge of a reactive lymphocyte is often indented by surrounding red blood cells. Atypical lymphocytes are associated with viral infections.

Front 20

What is a Large Granular Lymphocyte?

Back 20

Large granular lymphocytes (also called “natural killer cells” or NK cells) are a type cytotoxic lymphocyte that somewhat resemble reactive lymphocytes but are distinguished by prominent cytoplasmic granules. They constitute a major component of the innate immune system and play a major role in the rejection of tumors and of cells infected by viruses. They kill cells by releasing the contents of their cytoplasmic granules thereby causing the target cell to undergo apoptosis.

Front 21

What are monocytes?

Back 21

Monocytes mature in the bone marrow and travel to the tissues, where they are called macrophages, via the peripheral blood. They are relatively large cells with an indented or folded nucleus. The chromatin is not as coarse as that of a lymphocyte. No nucleoli are visible. There is abundant gray-blue foamy cytoplasm that may also contain vacuoles and a few granules. Monocytes are part of the innate immune system.

Front 22

What are platelets?

Back 22

Also shown are platelets. These are specialized, anucleate cells that are important in the initiation of hemostasis (when there is a wound) and the maintenance of vascular integrity. They are about ¼ the diameter of a red cell.

Front 23

What is a (basophilic) pronormoblast?

Back 23

The pronormoblast is the earliest red cell precursor identifiable in the bone marrow. It is a large cell with a round nucleus, fine, uncondensed chromatin, visible nucleoli, and a rim of dark blue cytoplasm. Note the perinuclear clearing at the 1 o’clock position. There are no cytoplasmic granules.

The basophilic normoblast is smaller than the pronormoblast and exhibits some condensation and coarsening of nuclear chromatin. The cytoplasm is still blue.

Front 24

What is a polychromatophilic normoblast?

Back 24

polychromatophilic normoblast, so called because the color of its cytoplasm is now more gray than blue. This reflects the combination of the blue-staining cytoplasmic RNA with the red-staining cytoplasmic hemoglobin that is being synthesized. It is smaller than the basophilic normoblast and exhibits even more chromatin condensation in it’s even smaller nucleus.

Front 25

What is an orthochromatophilic normoblast?

Back 25

The orthochromatophilic normoblast is so-called because its cytoplasm now has a distinct pink-gray tinge as cytoplasmic hemoglobin begins to predominate the cell’s color. The nucleus continues to decrease in size and the chromatin is now very condensed. The nucleus will become apoptotic and smaller and will be extruded from the cell.

Front 26

What is a polychromatophil?

Back 26

The polychromatophil is a young red blood cell that has a pinkish-bluish color because there remains some cytoplasmic RNA that stains blue amid the red hemoglobin. These cells are usually sent into the peripheral blood about 1 day before they will morphologically become mature erythrocytes. They are larger than mature red cells.

Front 27

Describe a mature erythrocyte

Back 27

The mature erythrocyte (red blood cell) is pink to red in color, has no nucleus, and, because of its biconcave discoid shape, has a central area of pallor that extends across the inner third of the cell diameter.z

Front 28

What is a hypochromic red cell?

Back 28

Hypochromic red cells, as may be seen in iron deficiency, exhibit a central area of pallor that is greater than the usual one third cell diameter. Some of the cells in this photomicrograph appear to have only a thin rim of hemoglobinized cytoplasm!

Normally, a RBC should have a cental area of pallor that is less than 1/3 the diameter of the cell. The normal size is that of a small lymphocyte nucleus.

Front 29

What is anisocytosis?

Back 29

Variation in RBC size in the same sample.

Front 30

What conditions can cause microcytic or amcrocytic anemias?

Back 30

Microcytic: Iron deficiency or hemoglobinopathies.

Macrocytic: B12 or folic acid deficiency, myelodysplastic syndromes.

Front 31

What is poikilocytosis?

Back 31

Presence of RBCs of different shape in the same sample (not to be confused with anisocytosis, which is RBCs of different SIZE in the same sample)

Front 32

What are spherocytes?

Back 32

Spherocytes are spherical, densely staining red cells that lack central pallor. They are seen in hereditary spherocytosis and immune hemolytic anemia.

Front 33

What are tear drop cells?

Back 33

Teardrop cells (dacrocytes) are red cells that are shaped like tear drops. They are seen in conditions where the bone marrow is invaded by fibrosis, tumor, granuloma or other infiltrative process.

Front 34

What are schistocytes?

Back 34

Schistocytes (keratocytes) are traumatized, fragmented red cells that are associated with thrombotic microangiopathic states or other causes of mechanical red cell trauma. The red cell fragments have sharp edges, may be triangular in shape, or may be shaped like military helmets.

Front 35

What are sickle cells?

Back 35

Irreversibly sickled cells (drepanocytes) are long narrow, curved red cells that taper to a point on at least one end. They are characteristic of the peripheral blood film in sickle cell disease and sickle cell anemia.

Front 36

what are target cells?

Back 36

Target cells (codocytes) are characterized by an area of dense staining at the center of the central pallor. Small (microcytic) target cells are characteristic of thalassemias and other hemoglobinopathies. Macrocytic targets may be seen in liver disease or obstructive jaundice.

Front 37

What is hemoglobin C?

Back 37

Hemoglobin C homozygotes exhibit target cells and the unique finding of rod-shaped crystals of hemoglobin C.

Front 38

What is basophilic stippling?

Back 38

Basophilic stippling refers to the presence of uniformly distributed punctate granules of dark blue throughout the red cell cytoplasm. The granules are darkly staining aggregates of ribosomes. This may occur in lead poisoning, sideroblastic anemia and thalassemia.

Front 39

What are Howell-Jolly bodies ?

Back 39

Howell-Jolly bodies are dark purple, dense, round inclusions with distinct borders. They are remnants of incompletely extruded nucleus, and are seen in the post-splenectomy state. They may also be present in myelodysplastic syndromes.

Front 40

What are Heinz bodies?

Back 40

Heinz bodies are round inclusions that stain dark blue with supravital stains (e.g. crystal violet). They are composed of denatured hemoglobin that binds to the cytoplasmic tail of integral membrane proteins, principally Band 3, in the red blood cell. They are characteristic of patients with glucose-6-phosphate dehydrogenase deficiency or unstable hemoglobins (e.g. Hgb H).

Front 41

What are the 3 key elements to hemostasis and clotting?

Back 41

(1) Vessel walls and endothelium
(2) Platelets - Cellular component
(3) Coagulation Factors - soluble plasma element

Front 42

What are the important intracellular components of endothelial cells?

Back 42

-Prostacyclin - inhibits platelet aggregation and causes vasodilation
-Nitric oxide (NO) inhibits plt activation and promotes vasodilation
-Thrombomodulin - combines with thrombin to activate protein C (inhibitor of coagulation)
-tissue plasminogen activator (tPA) which activates thrombolysis
-Von Willebrand's Factor (vWF)

Front 43

Describe the IMMEDIATE reaction of the vessel wall to an injury.

Back 43

1. Vasoconstriction of injured vessel slowing blood flow to affected area
2. Reduced flow allows contact activation of platelets and clotting factors. Platelets also activated by exposed collagen and vWF (vWF mediates platelet binding to subendothelium). Clotting factors activated by released tissue factor.
3. Platelets release prostaglandins and fibrinopeptides released in activating clotting factors also cause vasoconstriction and fibrin deposition.

FORMS A TIGHT PLUG, this is called PRIMARY HEMOSTASIS and occurs within minutes normally. Provides temporary bleeding relief but is unstable.

Front 44

What are activated platelets?

Back 44

platelets responding to vessel damage which release thromboxane causing platelet aggregation and vasoconstriction. Increased membrane surface area allows for more clotting factors to be activated on the cell surface. Kept in check by neighboring normal endothelial cells secreting prostacyclin and nitric oxide.

Front 45

Where is von Willebrand Factor produced and what does it do?

Back 45

In endothelial cells and megakaryocytes. Stored in ECs in Weibel-Palade bodies.

It binds and stabilizes factor VIII(8). Also binds subendothelium and platelets to form a bridge promoting platelet adhesion.

Front 46

What are the 3 platelet functions?

Back 46

The 3 As!

ADHESION (via vWF)
ACTIVATION/AMPLIFICATION (activated by collagen and thrombin which cause granule release and aggregation)
AGGREGATION - platelet X-linking via GPIIb/IIIa with fibrinogen

Front 47

Where are platelets produced?

Back 47

In the bone marrow from megakaryocytes.

Front 48

Where are clotting factors produced?

Back 48

In liver. with liver disease you will see bleeding symptoms.

Front 49

Which clotting factors require vitamin K for normal activity?

Back 49

II, VII, IX, X. Vit K allows carboxylation of glutamic acid residues, allowing calcium binding? Clotting can be blocked without vit K, as occurs in deficiency and coumarin therapy.

Front 50

What are clotting factors?

Back 50

Serine proteases that are normally inactive in circulation. Coagulation and CF activity stimulated by tissue factor. Form a cascade of protease cleavages leading ultimately to fibrin clotting of wounds.

Front 51

Which factors require vit K for normal activity and what is vit K used for?

When might vit K be low?

Back 51

II, VII, IX, X.

Carboxylates glutamic acid residues on factors allowing them to bind Ca++ and platelets.

Vit K deficiency, Coumarin interferes with normal vit K function.