Blood Composition and Function Quiz

Blood Composition and Function

• Blood is a specialized body fluid with diverse functions, including transporting oxygen and nutrients, carrying infection-fighting cells, removing waste, and regulating temperature.
• Whole blood is a mixture of approximately 55% plasma and 45% blood cells. A significant portion (7-8%) of a person's total body weight is blood.
• Blood is a highly specialized tissue consisting of over 4000 components.
• The most crucial components are red blood cells, white blood cells, platelets, and plasma.

Red Blood Cells (RBCs)

• Also known as erythrocytes, these are flattened, bi-concave cells.
• RBCs transport oxygen.
• A typical count ranges from 4 to 6 million cells per cubic millimeter of blood.
• RBCs are produced continuously in the bone marrow.
• Each RBC lives approximately 120 days before being destroyed in the liver or spleen.

White Blood Cells (WBCs)

• Also called leukocytes, WBCs are crucial to the immune system.
• Various types of WBCs exist, categorized as granulocytes and agranulocytes.

Platelets

• Also called thrombocytes, platelets are essential for blood clotting.
• They constitute less than 1% of blood volume.

Plasma

• Plasma is the liquid portion of blood, primarily 90% water.
• It contains dissolved materials like proteins, glucose, ions, hormones, and gases.
• Plasma acts as a buffer, maintaining a pH near 7.4

Blood Film Preparation (Experiment)

• The procedure typically involves obtaining a blood sample via finger puncture.
• A thin blood film (smear) is created by spreading a small blood droplet on a glass slide.
• The film is stained using Leishman's stain. This stain has components (eosin and methylene blue) that target certain aspects of the cells and their components, enabling differentiation.
• The stained film is examined under a microscope.

Types of Leukocytes

• Granulocytes (including neutrophils, basophils, and eosinophils) have granules in their cytoplasm.
• Polymorphonuclear cells have multiple lobes in their nuclei.
• Agranulocytes (including monocytes and lymphocytes) lack cytoplasmic granules.
• Monocytes and lymphocytes are mononuclear.
• Neutrophils are the most abundant type of WBC (60-70%).
• Basophils are less than 1% of WBCs.
• Eosinophils account for 2-4% of WBCs.
• Monocytes make up 3-8% of WBCs.
• Lymphocytes contribute 20% of WBCs.