Test 1 Flashcards
Where are the 2 places to obtain blood for hematology?
- Periferal blood via venipuncture. 2. Bone marrow via bone marrow aspiration.
Bone marrow is aka?
Myeloid, myelogenous or intramedullary tissue.
What is the most common type of hematologic test?
Complete blood count CBC.
In a CBC which cells are biggest and smallest?
Biggest—> smallest; WBC, RBC, HGB, HCT, MCV, MCH, MCHC, RDW, Platelets.
List WBC from largest to smallest?
Neutrophils, Band, Lymphocytes, Monocytes, Eosinophils, Basophils.
What is hematopoiesis?
The formation and development of all types of blood cells from their parental precursors.
Where will a fetus’s hematopoiesis happen at?
Starts with yolk sack then moves to liver and spleen, then axial skeleton.
Where will an adult’s hematopoiesis happen at?
For the first few decades in the distal long bones and axial skeleton, and then later in life mainly the axial skeleton.
What is erythropoiesis?
Production of RBC and it is a type of hematopoiesis.
What will the cytoplasm color be like from beginning to the end of erythropoiesis?
It will start blue and eventually turn to orange.
During erythropoiesis it starts with a stem cell—> progenitor cell —-> ?
Rubriblast.
1 Rubriblast will eventually make how many RBC?
Many.
How long will erythropoiesis take?
5-6 days for bone marrow development.
What is the nucleus like during erythropoiesis?
It is present at the beginning and will disappear after 2-3 days.
What is the name of the first cell during erythropoiesis that will not have a nucleus?
Reticulocyte.
What part of erythropoiesis will cells enter the circulating blood?
Very promptly, even before the last maturational events have occurred as reticulocytes.
How long will a RBC last in circulation and what will happen to it?
120 days, senescence and destruction.
What is the last stage of RBC maturation that occurs after the nucleus is extruded in the bone marrow?
Reticulocyte.
Why are reticulocytes slightly larger than Mature RBC?
Because they are still maturing and contain residual fragments of cytoplasmic RNA and mitochondria.
Why will reticulocytes have a different color than mature RBC’s and what is the color?
Polychromatic from fragments of mitochondria.
When will reticulocytes finish maturing?
1-2 days after entering the peripheral circulation.
What % of circulating Red cells are reticulocytes?
0.5-2.5 %.
What are reticulocytes counts commonly used for?
Diagnosis of various anemia and in monitoring the recovery in factor deficiency anemias.
Will a CBC have a reticulocyte count?
No.
Where will erythropoietin be made at?
Peritubular interstitial cells of the kidenys.
When will erythropoietin be made?
With blood loss the kidneys sense a loss of O2 and make EPO. This can also happen with chronic obstructive pulmonary disease since O2 levels will be low.
What will EPO do?
Increases the number of stem cells that commit to rubriblasts, and speeds up the maturation time by 20-30%. EPO also allows for early release of immature cells into peripheral circulation.
Where is hemoglobin synthesized at?
Within the maturing nucleated red cell within the bone marrow via a series of biochemical enzymatically driven reactions intimately involving the mitochondria.
How is heme produced?
when iron is enzymatically inserted into protoporphyrin.
How is globin produced?
Polyribosomes produce globin chains in pairs (alpha, gamma, beta, delta).
Each globin chain provides what?
a site for insertion of one heme molecule.
What will go into making 1 hemoglobin?
four globin chains (2 pairs) and four heme molecules.
How can different types of hemoglobin be made?
Various combinations of pairings of globin chains produce different types of hemoglobin.
What type of hemoglobin will fetuses make?
F= 2 alpha, 2 gamma globulins.
What type of hemoglobin will infants make?
95-97% is A1- 2 alpha, 2 beta globulins. And 2-3% will be A2- 2 alpha, 2 delta globulins.
What test can be done to determine what types of hemoglobin are present?
Hemoglobin electrophoresis.
How will iron be transported in the body?
By transferrin.
Iron is essential for what?
Erythropoiesis.
What % of dietary iron is absorbed and where?
10% is absorbed via proximal small intestine.
What happens to dietary iron not absorbed?
Excreted in feces, and small amounts in urine.
Where will transferrin take iron once in the plasma, and what will the iron do in these places?
Bone marrow- hemoglobin synthesis. Muscles- myoglobin synthesis. Liver- storage.
Name 4 tests that reflect the status of iron metabolism?
- Serum iron concentration (SI). 2. Total iron binding capacity (TIBC). 3. % saturation of iron (% sat or TSAT). 4. Serum ferritin concentration.
What is the serum iron concentration (SI) test?
the concentration of circulating iron that is bound to transferrin.
Is SI a good test for iron metabloism why or why not?
No there are physiological causes of altered concentrations.
What is total iron binding capacity (TIBC)?
An indirect assay of transferrin concentration performed by measuring the amount of iron (added in vitro) needed to totally saturate the unbound iron-binding sites on the transferrin molecules.
Normally how many of the transferrin binding sites are bound with iron?
only 1/3.
TIBC should not be ordered as what type of test?
An individual test it should be ordered in combination with the SI.
% saturation of iron test?
Calculated value estimating the % of binding sites on transferrin that are bound with iron.
What is needed to measure the % saturation of iron test?
SI and TIBC.
% saturation of iron test is much more sensitive indicator of what?
Iron deficiency or iron overload than is SI.
How is iron stored in the body?
Ferritin is the body’s major iron storage compound.
Where is ferritin found at?
In nearly every cell, but the major sites of storage are hepatocytes, spleen, and bone marrow.
Each ferritin molecule contains how much iron?
as many as 4,000 iron molecules.
Ferritin that is in circulation is in direct proportion to what?
The amount of ferritin stored in the tissues.
OF all the tests what is the gold standard to evaluate iron storage?
Serum ferritin.
What type(s) of test(s) should be done to investigate iron related abnormalities?
SI< TIBC, % sat, and serum ferritin.
Name 3 groups of white blood cells?
Granulocytes, lymphocytes, and monocytes.
What are granulocytes?
Maturation of leukocytes that contain granules so they are Neurtophils, eosinophils and basophils.
Production and maturation of granulocytes is under what influence?
Humoral growth factors.
What is the difference between erythropoisis and granulopoiesis?
With granulopoiesis stem cells commit, differentiate and accumulate into different compartments or pools both within and outside of the bone marrow.
Where will granulocytes pool?
about 50% are available mature granulocytes circulating.
What else besides humoral growth factors can influence leukocyte production?
Chemical mediators (cytokines and chemokines) released during inflammatory and immune reactions.
Granulocytes have how long of a life span and are in circulation how long?
They live for 9-15 days and are in circulation 7-24 hours.
What is a band neutrophil?
An immature form of neutrophil which is observed both within and outside of the bone marrow.
What is a PMN?
a mature neurtophil.
What is shift to the left?
Any increase in numbers of immature neurotphils in peripheral circulation.
Shift to the left is indicative of what?
acute infection or other cause of neutrophila.
What is lymphopoiesis?
Growth and maturation of lymphocytes.
Where will lymphocytes mature at?
within bone marrow and is mediated by a poorly understood control mechanism.
What do lymphocytes do in circulation?
repopulate lymph nodes and lymphatic tissue.
Lymphocytes are conditioned by what?
Thymus- T-lymphocytes. Bone marrow- B lymphocytes.
T-lymphocytes and B-lymphocytes are for what?
T- cellular immunity. B- humoral immunity.
What are atypical lymphocytes?
Abnormal appearing T-lymphocytes usually observed in peripheral blood of an immunologically stimulated patient, most often viral infections.
Atypical lymphocytes are classically seen with what and are aka?
Mononucleosis and may be known as Downey cells or reactive lymphocytes.
What is the name of WBC when they are elevated and decreased?
Elevated; neutrophilia, lymphocytosis, moncytosis, eosinophilia, basophilia. Decreased; neutropenia, lymphocytopenia, moncytopenia, eosinopenia, basopenia.
What can cause neutophilia?
physical or emotional stress, acute suppurative infeciton, myelocytic leukemia, inflammatory disorders.
What can cause lymphocytosis?
Chronic bacterial infections, viral infections, lymphocytic leukemias.
What can cause moncytosis?
Chronic inflammatory disorders, tuberculosis.
What can cause eosinophilia?
Parsitic infections, allergic reactions, hodgkin lymphoma.
What can cause basophilia?
Myeloproliferative diseases.
What can cause neutropenia?
dietary deficiencies (B12 and folate), some overwhelming bacterial infections, viral infections, radiation and chemotherapy.
What can casue lymphocytopenia?
Immunodeficiency diseases, radiation therapy.
What can cause moncytopenia?
Very uncommon.
What can cause eosinopenia?
Very uncommon.
What can cause basopenia?
Very uncommon.
Is platelet count part of the CBC?
Yes.
What is megakaryopoiesis?
Production of thrombocytes (platelets).
Maturation and growth of thrombocytes is influenced by what?
Thrombopoietin TPO, megakaryocyte growth and development factor MGDF, and same cytokines and chemokines as granulocytes.
Name 3 tests to evaluate hematopoeiesis?
CBC, reticulocyte count, bone marrow aspiration and biopsy.
Are there any special times of collection or patient preparation needed for a CBC?
No.
What is a RBC count?
Absolute quantification of RBCs in a unit volume of blood.
What are the units for conventional and international for a red blood count?
Conventional- mm^3. International- L
How often is a Red blood cell count used alone?
Not often not even to determine if a blood transfusion is needed.
What is the most widely used single test used to evaluate a patient for anemia?
Hemoglobin concentration.
What is a hemoglobin concentration test testing?
Direct measurment of the weight of hemoglobin in a unit volume of blood.
What are the conventional and international units used for hemoglobin concentration tests?
Conventional- gm/dL. International- gm/L
What is the hematocrit test testing?
The ratio of the volume of the RBCs after centrifugation to that of whole blood.
Hematocrit is aka?
crit, and packed cell volume PCV.
What are the conventional and international units used for the hematocrit test?
Conv- %. Internat- L/L
How can the PCV aka hematocrit(HCT) aka crit approximate the hemoglobin (HGB)?
Divide the HCT by 3.
What are the RBC, HGB, HCT tests used to determine?
Anemia, erythrocytosis, and polycythemia.
What are the 3 types of polycythemia and what are they?
Polycythemia vera- myeloproliferative disorder. Secondary polycythemia- hypoxia= not getting enough oxygen. Relative polycythemia- dehydration.
Name the RBC indicies?
mean corpuscular volume MCV, Mean corpuscluar hemoglobin MCH, Mean corpuscular hemoglobin concentration MCHC.
What is MCV?
Measure of the intracellular volume of the average circulating RBC. So this is the size of the average circulating RBC.
What are the units used for MCV?
fenta Liter.
Name 3 types of anemias?
microcytic, macrocytic, normocytic.
What will the MCV test be like for the 3 types of anemia?
Microcytic- decreased MCV. Macrocytic- Increased MCV. Normocytic- normal MCV.