110.1

Define anticoagulant

Substance that prevents blood from clotting

List the three layers that can be seen in an anticoagulated tube

Plasma

Buffy coat

RBCs

What portion of the blood do we mainly study in hematology?

RBCs

What are the usual two methods of obtaining a blood specimen for testing?

Venipuncture

Capillary puncture

What is the name of the anticoagulant usually used in hematology?

EDTA (Ethylenediamintetracetic Acid)

What is the color of the stopper of the EDTA tube?

Lavender

How does a tech make sure that she/he obtains a well-rounded drop of blood when performing acapillary puncture?

Kneading/ massaging the area

Stick across the fingerprints

What are several sources of error in performing a capillary puncture?

Hemolysis

Excessively deep puncture

Failure to wipe off first drop of blood

Air bubbles in tube

What is the most accurate test performed by capillary puncture?

Hemocrit

What is the technical name for an RBC?

Erythrocyte

What are 4 reasons EDTA is used as an anticoagulant in hematology?

Preserves size and shape of cells

Usually prevents platelet clumping

Artifacts form slowly

Can be used for up to 24 hours if refrigerated

What test values when performed from capillary collections are lower than venous collection?

Platelets

What test value when collected by capillary collection will be higher than a venous collection?

RBCs

Hemoglobin

Hemocrit

WBCs

Why is the first drop of blood wiped off when performing a capillary puncture?

Tissue fluid contamination

Platelet clumps

Define Erythro-

Red

Define Leuko-

White

Define Thrombo-

Clotting

Define Oligo-

Few or scarcity

Define -penia

Deficiency or decrease

Define -poiesis

Formation

An act or process of creation

Define -a/-an

No

Not

Without

Define Iso-

Equal

Define -cyte

Cell

Define -osis

Abnormal condition

Indicating condition, status, progress

Define -emia

Blood condition

Define Peri-

Around or about

Define -crit

measure

What are the standard Hematology reference ranges for women?

RBCs: 4.2-5.4 x 10^6/uL

Hemoglobin: 12-16 g/dL

Hemocrit: 37-47%

What are the standard Hematology reference ranges for men?

RBCs: 4.7-6.1 x 10^6/uL

Hemoglobin: 14-18 g/dL

Hemocrit: 42-52%

What are the standard Hematology reference ranges for Neonates?

RBCs: 4-6 x 10^6/uL

Hemoglobin: 17-23 g/dL

Hemocrit: 53-65%

In what two ways are the Hematology reference ranges reported?

Conventional & SI units

What fingers and what areas are acceptable puncture sites for capillary puncture?

Middle and ring finger

Sides of heel

What are acceptable puncture sites and area for capillary puncture on an infant?

Sides of heel

How does each of the following anticoagulants prevent clotting: Trisodium Citrate

Binds calcium

How does each of the following anticoagulants prevent clotting: Heparin

Prevents the formation of Thrombin

How does each of the following anticoagulants prevent clotting: EDTA

Chelates calcium

What hormone causes increased erythropoiesis?

Erythropoietin

Where is Erythropoietin produced?

In the kidneys

What is the chemical property of the hormone that controls erythropoiesis?

Glycoprotein hormone

The percentage of the blood that is composed of cells is ________ and the percentage of the fluid in the blood is _______.

45%

55%

What two components make up the hemoglobin molecule?

Heme

Globin

How many of the Heme and Globin components are in a hemoglobin molecule?

4 of each

What are the primary functions of hemoglobin?

Transport respiratory gases

Acid-base balance

What are the three hemoglobins found in the normal adult?

Hemoglobin A (A1)

Hemoglobin A2

Hemoglobin F (Fetal)

How does each of the three Hemoglobins differ structurally?

Hem A1: 2 alpha globins & 2 beta globins

Hem A2: 2 alpha globins & 2 delta globins

Hem F: 2 alpha globins & 2 gamma globins

What percent of each hemoglobin is normally present in the adult?

Hem A1: 97%

Hem A2: ~2%

Hem F: ~1%

Name two abnormal hemoglobins?

Hemoglobin S

Hemoglobin C

Describe the structural abnormality of the abnormal Hemoglobins

Hem S: Valine instead of Glutamic Acid on the Beta globin chain

Hem C: Lysine instead of Glutamic Acid on the Beta globin chain

What percentage of the RBC is occupied by hemoglobin?

33.3%

One_____ of hemoglobin can combine with __________ of oxygen.

1g

1.34 mL

What is the advantage to a newborn to have more hemoglobin F than a child of age one or an adult?

Hem F has a high affinity for oxygen

Fetuses in the womb are in a low oxygen environment

What are the two normal hemoglobin pigments?

Oxyhemoglobin

Deoxyhemoglobin

How do the two normal hemoglobin pigments differ?

Oxyhemoglobin: Hemoglobin with Fe2+ (Ferrous) & O2 - arterial

Deoxyhemoglobin: Hemoglobin with Fe3+ (Ferric) with no O2 - venous

What are the three abnormal hemoglobin derivatives?

Methemoglobin

Sulfhemoglobin

Carboxyhemoglobin

What are the three abnormal hemoglobin derivitives composed of?

Methemoglobin: Hemoglobin with Fe 3+

Sulfhemoglobin: Hemoglobin with Sulfer

Carboxyhemoglobin: Hemoglobin with Fe 2+ and Carbon Monoxide

Can the three abnormal hemoglobin derivatives be reversed?

Methemoglobin: Yes, methylene blue, hyperbaric O2, or transfusions

Sulfhemoglobin: No, they are destroyed at the end of their life span

Carboxyhemoglobin: Yes, by giving pure O2

Hemoglobin is found inside the ______?

Red Blood Cell

What is the test that measures the percentage of RBCs in a given volume of whole blood when it has been spun?

Microhematocrit

What is the reagent used in the Cyanmethemoglobin method?

HiCN (Hemoglobin Cyanide) (Drabkin's)

What is poisonous component found in HiCN?

Cyanide

What is the relationship of the hemoglobin to the hematocrit and vice versa?

Hgb x 3 = Hct +/- 3

Hct / 3 = Hgb +/- 0.5

If a patient's hematocrit was 36.0%, what would you expect the hemoglobin result to be?

11.5-12.5 g/dL

What clinical condition is characterized by a pancythemia (increase in the RBCs, WBCs, and platelets)?

Polycythaemia Vera

Name some conditions that would cause an increase in RBC count, Hgb and Hct.

High altitudes

Dehydration

Polycythemia Vera

Name some conditions that would cause a decrease in RBC count, Hgb and Hct.

Low altitudes

IV fluids

Pregnancy

Leukemia

Anemia

Hemorrhage

Name some sources of error in microhematocrit testing.

Centrifuge too short/slow

Delay in reading results

Trapped plasma

Tubes not sealed

Overly anticoagulated blood

Name some sources of error in Hemoglobin testing.

Cloudiness

High WBC count

Hem S or Hem C (resistant to lysis)

Lipemia or Icteria

What is the average size of an RBC?

6-9 microns in diameter

Define Pallor

The central part of an RBC

How much of a cell with the pallor take up?

1/3rd of the cell

Define MCV

Mean Corpuscular Volume

The average size of an RBC cell

MCV = (Hct x 10)/RBC

80-100 fL

<80 = microcytic

>100 = macrocytic

Define MCH

mean corpuscular hemoglobin

Hgb weight

MCH = (Hgb x 10)/RBC

27.00-31.0 pg

What is the MCHC?

Mean Corpuscular Hgb

average concentration of Hgb

(Hgb x 100)/Hct

Normal: 32-36 g/dL

Hypochromic: <32 g/dL

Hyperchromic: >36 g/dL

Define Anisocytosis

The variation in size of RBCs on a smear

RDW > 14.5%

What are the differences between Normochromatic RBC cells, Hypochromatic RBC cells, and Hyperchromatic RBC cells?

Normochromatic: Normal pallor

Hypochromatic: Larger pallor

Hyperchromatic: Little/no pallor

Define RDW

red cell distribution width

11.5-14.5%

Hemocue principle

Sodium deoxycholate hemolyzes the erythrocytes, liberating hemoglobin that reacts with sodium nitrite to form methemoglobin, which then reacts with sodium azide to form azide methemoglobin. Azide methemoglobin is measured by the photometer