Stages of Blood Cell Development

Stages of Blood Cell Development

• Blood is composed of water, plasma proteins (albumins, globulins, fibrinogen, regulatory proteins), electrolytes, nutrients, respiratory gases, waste products, erythrocytes, leukocytes, and platelets.
• Erythrocytes (RBCs) are the most abundant blood cells.
  • Shape: Flexible, biconcave discs
  • Size: Diameter 6-9 µm (average 7.5 µm), Thickness: about 2.5 µm at the rim and 0.75 µm in the center.
  • Non-nucleated
  • Appear ac-dophilic with a pale center
  • Life span: 120 days, then they're engulfed by macrophages.
  • Abnormal shapes include sickle-shape and spherocytosis (biconvex).
  • Abnormal sizes include microcytic (diameter < 6 µm) and macrocytic (diameter > 9 µm).
• Leukocytes (WBCs) are a crucial part of the immune system.
  • Types: Neutrophils (60-70% of circulating leukocytes, 12-15 µm in diameter, segmented nucleus, cytoplasmic granules), Basophils (less than 1% of circulating leukocytes, 12-15 µm in diameter, bilobed nucleus, characteristic cytoplasmic granules, life span of 10-15 days), Eosinophils (2-4% of circulating leukocytes, 12-15 µm in diameter, bilobed nucleus, characteristic cytoplasmic granules, life span of 8-12 days), Monocytes (3-8% of circulating leukocytes, largest in blood smear, 15-20 µm in diameter, large indented or kidney-shaped nucleus, basophilic cytoplasm with azurophilic granules, life span of 3 days), Lymphocytes (20-25% of circulating leukocytes, 10-12 µm in diameter, small, spherical, highly condensed nucleus with rim of cytoplasm).
• Platelets (thrombocytes) are cell fragments crucial for blood clotting.
  • Diameter: 2-4 µm
  • Normal count: 150,000 to 400,000/µL of blood
  • Life span: about 10 days
  • Appear in clumps in stained blood smears.

Blood Smear Preparation

• Collect a small blood sample.
• Place a drop of blood on a slide.
• Using a second slide, spread the blood into a thin film.
• Allow to dry and stain.
• View under a microscope to see the different blood components

Hemopoiesis

• Hemopoiesis in the bone marrow results in the formation of blood cells.
• Hematopoietic stem cells are the precursors of all blood cells.
• Myeloid stem cells differentiate into erythrocyte, platelets, and granulocytes (neutrophils, eosinophils, basophils) and monocytes.
• Lymphoid stem cells differentiate into lymphocytes (B cells, T cells, NK cells).

Explore the fascinating stages of blood cell development, focusing on erythrocytes and leukocytes. This quiz covers their structure, types, functions, and abnormalities. Test your knowledge on the cellular components of blood and their roles in the immune system.