Hematology Blood Exam Quiz

Hematologic Exams

• Hematology is the study of blood and blood-forming tissues, including causes, prognoses, and treatments of blood-related disorders.
• Blood comprises 6-8% of normal adult body weight, approximately 5 liters.
• Blood components include plasma (55%), cellular/formed elements (45%), and the buffy coat (less than 1%).
  • Plasma, the liquid portion, is mostly water (91%), containing dissolved gasses, salts, glucose, proteins (like albumin, antibodies, amino acids, and lipids), vitamins, and electrolytes.
  • Cellular/formed elements include Red Blood Cells (RBCs), White Blood Cells (WBCs), and Platelets.
  • Buffy coat: leukocytes (white blood cells) and platelets, less than 1%.

Hemoglobin Tests

• Hemoglobin, a protein, gives blood its red color. It carries oxygen via oxyhemoglobin and releases it as deoxyhemoglobin.
• Hemoglobin measurements assess the oxygen-carrying capacity of the blood.
• Hemoglobin is an important indicator of blood loss and anemia.
• Methods for measurement include chemical methods (e.g., cyanmethemoglobin), Sahli method, and others.

Hematocrit Determination

• Hematocrit measures the percentage of blood volume occupied by RBCs.
• It's used to diagnose conditions such as anemia (low hematocrit) and polycythemia (high hematocrit).
• Methods include manual Wintrobe method and microhematocrit methods.

Complete Blood Count (CBC)

• CBC examines blood components including RBCs, WBCs, and platelets.
• CBC tests include RBC count, WBC count, hemoglobin, hematocrit, and RBC indices.
• RBC count measures the number of RBCs per unit volume.
• WBC count measures the number of WBCs per unit volume.

Red Blood Cell (RBC) Indices

• Indices like MCV (mean corpuscular volume), MCH (mean corpuscular hemoglobin) and MCHC (mean corpuscular hemoglobin concentration) provide information about the size and hemoglobin content of RBCs.
• These indices are used in the diagnosis and monitoring of anemias.

White Blood Cell (WBC) Count

• WBCs are important components of the immune system.
• WBC counts are used in diagnosing infections and other conditions.
• WBC counts should be within a specific range, with deviations indicating possible issues.

Platelets

• Platelets are essential for blood clotting and hemostasis.
• Their low or high counts can indicate conditions requiring medical attention.

Other Important Information

• Blood donation removes RBC wastes, causing the body to produce new blood cells.
• Blood samples are often diluted prior to counting cells. Specialized fluids are used in diluting the blood to avoid harming the cells.
• Correct methods for counting cells are required to avoid mistakes and errors.