Introduction to Hematology

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Questions and Answers

Which type of vacutainer is used specifically for blood glucose determination?

Grey (correct)

Light yellow

Purple

Green

What additive is common in both dark blue and green vacutainers?

EDTA

Thrombin

Lithium Heparin

Sodium Heparin (correct)

Which vacutainer type is primarily used in immunology and requires serum separation?

Orange or Grey/Yellow 'Tiger' Top

Gold or 'Tiger' Red/Black Top (correct)

Light blue

Tan

For which procedure are purple or lavender top vacutainers primarily utilized?

Complete blood counts (CBC) Signup and view all the answers

What is the function of the sodium citrate present in light blue vacutainers?

To act as a reversible anticoagulant Signup and view all the answers

Which vacutainer type is used for rapid serum testing and contains a thrombin additive?

Orange or Grey/Yellow 'Tiger' Top Signup and view all the answers

Tan vacutainers are primarily used for which type of testing?

Lead content determinations Signup and view all the answers

Which of the following color-coded vacutainers contains potassium salt of EDTA?

Purple or lavender Signup and view all the answers

What effect does warming the puncture site have on the capillary blood specimen?

It makes the specimen more similar to arterial blood. Signup and view all the answers

In which population is skin puncture most commonly performed?

Newborns and pediatric patients under 1 year. Signup and view all the answers

Which factor can cause an increase in the packed cell volume (PCV) of a blood sample?

RBC swelling from improper storage. Signup and view all the answers

What should be done with the first drop of blood collected during a capillary puncture?

It should be wiped away. Signup and view all the answers

Which fasting practice is recommended before preserving blood samples?

Allow the blood to warm to room temperature. Signup and view all the answers

When is the reticulocyte count expected to decrease after blood collection?

As early as 6 hours. Signup and view all the answers

What is a proper action to take while performing a capillary puncture?

Wear appropriate personal protective equipment (PPE). Signup and view all the answers

Which site is NOT recommended for capillary blood collection in infants?

Finger. Signup and view all the answers

What is the characteristic thickness of blood measured in comparison to water?

4-5 times thicker than water Signup and view all the answers

Which of the following is NOT a function of blood?

Production of hormones Signup and view all the answers

What percentage of total body weight does blood constitute?

8% Signup and view all the answers

During venipuncture, what is the purpose of applying a tourniquet?

To restrict blood flow and make veins more prominent Signup and view all the answers

Which of the following blood components is most abundant in the blood?

Red blood cells Signup and view all the answers

Which complication may occur if a tourniquet is applied for too long during venipuncture?

Hemoconcentration Signup and view all the answers

What is the ideal pH range of blood?

7.35-7.45 Signup and view all the answers

Which method of blood collection is particularly suited for pediatric patients?

Skin puncture Signup and view all the answers

What is the recommended order for drawing blood samples with additives?

Culture bottles, Red, Blue, Green, Lavender, Gray Signup and view all the answers

Which of the following is a primary component of the buffy coat?

Leukocytes Signup and view all the answers

Study Notes

What is Hematology?

Hematology focuses on the study of blood, specifically its cellular components and functions.

Physical Characteristics of Blood

Blood is more viscous than water and has a flow rate that is slower than water.
Average blood temperature is 100.4°F (38°C) with a pH of 7.4 (ranging from 7.35 to 7.45).
Blood constitutes about 8% of total body weight, averaging 5-6 L in males and 4-5 L in females.
Viscosity measured at 4-5 (water = 1), with osmolarity at 300 mOsm.
Salinity is approximately 0.85%.

Functions of Blood

Distribution:
- Carries oxygen from lungs and nutrients from digestive tract to cells.
- Transports metabolic wastes to lungs and kidneys for elimination.
- Delivers hormones from endocrine glands to target organs.
Regulation:
- Maintains body temperature through heat distribution.
- Regulates normal pH using buffer systems in tissues.
- Ensures adequate fluid volume in circulatory system.
Protection:
- Prevents blood loss by activating plasma proteins and platelets, initiating clot formation.
- Fights infection by synthesizing antibodies, activating complement proteins, and mobilizing white blood cells.

Blood Components

Blood is composed of 55% plasma (contains nutrients, gases, ions, hormones) and 45% cellular elements.
Cellular elements consist of 99% red blood cells (RBCs), 1% white blood cells (WBCs), and platelets.
The buffy coat contains platelets and various types of leukocytes (neutrophils, eosinophils, basophils, monocytes, lymphocytes).

Basic Methods of Hematological Examinations

Common examination includes Full Blood Count (CBC) assessing RBC, Hb, leukocyte differentials, and platelets.
Morphological examination through blood film preparation and staining.

Blood Collection Procedures

Collection methods include venipuncture, arterial puncture for arterial blood gas (ABG), and skin puncture (commonly for pediatric patients).
Proper site cleansing and patient positioning are essential before venipuncture.

Venipuncture Technique

Utilize an evacuation system (VACUTAINER) or needle and syringe system.
Confirm patient details, required specimen type (fasting or non-fasting), and prepare equipment for collection.

Phlebotomy Complications

Possible complications include ecchymosis (bruising), hematoma, excessive bleeding, thrombosis, infection, and fainting (syncope).
Hemoconcentration can occur due to prolonged tourniquet application.

Order of Draw for Blood Samples

Always draw specimens from non-additive tubes first.
Follow a specific order for tubes with additives: Blood culture bottles → Red stopper → Blue stopper → Green stopper → Lavender stopper → Gray stopper.

Commonly Used Evacuated Tubes

Various color-coded tubes serve specific purposes, e.g., gold/tiger tops for chemistry tests, green for plasma determinations, purple/lavender for blood counts, and gray for glucose testing.

Capillary Blood Collection

Capillary blood draws may utilize venous, arterial, and tissue fluids, with WBC counts typically 15-20% higher than venous specimens.
Collection typically performed on infants via heel or finger puncture, ensuring proper technique.

Preservation of Blood Samples

Blood can be preserved at 4°C in a refrigerator. Prior to testing, blood should be warmed to room temperature.
Changes during preservation include swelling of RBCs, decreased reticulocyte counts, and potential changes in osmotic fragility and PT over time.

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Description

Explore the fundamental concepts of hematology, focusing on the study of blood, its physical characteristics, and essential functions. This quiz will cover aspects such as blood composition, distribution of resources in the body, and regulatory mechanisms that maintain homeostasis.