Hematology

Question 1

Blood consists of plasma and formed elements. There are 3 distinct layers found in blood when drawn in a tube with an
anticoagulant present. What are the blood Components and what do they consist of?

Answer 1

Plasma
◦ Makes up 55% of blood
◦ Straw color
◦ Contains cellular elements and dissolved substances

Buffy coat
◦ <1% of whole blood sample
◦ Contains WBCs and platelets

Erythrocytes
◦ Packed RBCs

Question 2

Describe the function and appearance of an RBC

Answer 2

• Anucleated, biconcave, discoid cells filled with
  reddish protein, and hemoglobin

*Transports oxygen and carbon dioxide

*Appearance
◦ Salmon pink
◦ 7-8 μm in diameter
◦ Biconcave zone of pallor
◦ 2/3 of the center
120 days in circulation

Question 3

Describe the function and appearance of an Platelet

Answer 3

*Thrombocytes

*Small fragments of cytoplasm derived from
megakaryocytes

*Blood cells that maintain blood vessel
integrity by initiating vessel wall repairs

*Rapidly adhere to damaged blood vessel and
forms a platelet plug with neighboring
platelets and release small molecules that
trigger thrombosis or clot formation

*Appearance:
◦ 2-4 μm
◦ Round or oval, anucleated
◦ “cell fragments”
◦ Slightly granular