Chapter 19 Flashcards
Clinical Laboratory
Which of the following is considered the preferred source for blood specimens obtained for clinical examination?
1. Venipuncture
2. Finger puncture
3. Arterial puncture
4. Antecubital puncture
For most clinical laboratory tests requiring a blood specimen, venous blood obtained by venipuncture is preferred.
For most clinical laboratory tests requiring a blood specimen, venous blood obtained by venipuncture is preferred.
When performing a finger puncture, the first drop should be wiped away to avoid which of the following conditions?
- Bacterial contamination
- Clotting at the puncture site
- Dilution of the specimen with alcohol
- Dilution of the specimen with tissue fluids
Wipe away the first drop of blood with a sterile 2 x 2 gauze. This prevents contamination of the specimen with excess tissue fluid.
How far above the intended phlebotomy site should the tourniquet be placed?
- Directly above site
- 1-2 inches above the site
- 2-3 inches above the site
- 3-4 inches above the site
Apply tourniquet around the arm approximately 3 to 4 inches above the intended venipuncture site, usually the antecubital fossa.
The correct needle position for venipuncture is (a) what degree angle and (b) with the bevel in what position?
- (a) 15-30 (b) up
- (a) 20-40 (b) down
- (a) 15-30 (b) down
- (a) 20-40 (b) up
Using a smooth continuous motion, introduce the needle, bevel side up, into the vein at about a 15 to 30 degree angle with the skin.
A tourniquet is normally applied before to aid in the process of venipuncture. At what point in the venipuncture procedure should the tourniquet be removed?
- Just before needle insertion
- Just after needle insertion
- Once blood flows freely into tubes
- No longer than two minutes
The tourniquet should be removed as soon as blood flows freely into the tubes. In some difficult draw situations, the tourniquet is sometimes left on until the last tube is filled. Do not leave the tourniquet on for more than one minute.
Which color tube is the best choice for a CBC?
- Red top
- Lavender top
- Gray top
- Yellow top
A lavender-top is often used for complete blood counts (CBCs), and a red-top is often used for blood chemistry.
The part of the microscope on which the prepared specimen is placed for examination is called the ________ .
- Arm
- Base
- Frame
- Mechanical stage
Mechanical (movable) Stage holds the specimen in place and is the means by which the specimen may be moved about on the stage to view the sample.
What objective should be used for a detailed study of stained bacterial smears?
- Low power
- Oil immersion
- High power
- Either 2 or 3 above
The oil-immersion objective (100X) is used for detailed study of stained blood and bacterial smears.
A Complete Blood Count includes which of the following?
- Total RBC count
- Hematocrit
- Differential WBC count
- All of the above
A complete blood count routinely consists of the following tests: • Total red blood cell (RBC) count • Hemoglobin determination (Hgb) • Hematocrit calculation (Hct) • Total white blood cell (WBC) count • White Blood Cell Differential count
Which of the following factors affect the hemoglobin values?
- Age
- Sex
- Altitude
- All of the above
Values are affected by age, sex, disease, and altitude. Different situations affect the function of hemoglobin in different ways. For example, iron deficiency anemia may drop hemoglobin from a normal value to a critically low value.
The normal value for male hemoglobin is?
- 10-16
- 12-18
- 14-18
- 15-20
The normal values for hemoglobin determinations are: Grams per 100 ml blood
Woman …….. 12 to 16
Men …………. 14 to 18
Select the term used to describe an abnormally high WBC count.
- Leukocytosis
- Erythrocytosis
- Leukopenia
- Pancytopenia
When the WBC rises above normal values, the condition is referred to as leukocytosis.
What is the SF-545?
Laboratory Report Display form
What does a red cell count that drops below normal values indicate?
Anemia
What does a red cell count that is above normal values indicate?
dehydration
