Given below is a diagram of a human blood smear. Study the diagram and answer the questions that follow: Given below is a diagram of a human blood smear. Study the diagram and answer the questions that follow:
Name the components numbered ‘1’ to ‘4’.
Topic: Components of blood
Answer
1 — RED BLOOD CELLS (erythrocytes) 2 — WHITE BLOOD CELLS (leucocytes) 3 — BLOOD PLATELETS (thrombocytes) 4 — PLASMA
Identify them by SIZE and by the presence of a NUCLEUS, which is how they are told apart under a microscope: RED CELLS — most numerous, round biconcave discs with NO nucleus and a pale centre WHITE CELLS — largest, fewest, irregular in shape, each WITH a prominent nucleus PLATELETS — smallest, irregular fragments with no nucleus PLASMA — the pale fluid in which all of them float
The proportion is worth knowing: about 600 red cells to every white one, which is why a smear looks overwhelmingly red.