Blood Composition Overview

What percentage of leucocytes do eosinophils represent?

Which type of cells are directly responsible for the production and carriage of histamine and heparin?

Which of the following functions is associated with lymphocytes?

What is the predominant type of granulocyte that is highly phagocytic and represents the largest percentage of leucocytes?

What type of cells are monocytes classified as?

What is the primary function of red blood corpuscles (RBCs)?

Which component makes up the majority of blood volume?

How long do red blood corpuscles (RBCs) typically live?

Which type of white blood cell is most abundant and is primarily involved in defense against infections?

What percent of blood plasma is approximately made up of water?

What is the normal range of white blood corpuscles (WBCs) per cubic millimeter in healthy individuals?

Which of the following is NOT a component of blood plasma?

Where are red blood corpuscles (RBCs) primarily produced?

Blood Composition

Blood is a fluid tissue, suspended in watery plasma, constantly circulating through blood vessels by heart action.
Blood comprises 45% cells and 55% plasma.

Blood Cells

Red Blood Cells (RBCs) / Erythrocytes:
- 45% of blood volume
- Biconcave discs, non-nucleated.
- 5.4 million/mm³
- Carry oxygen (O2) and carbon dioxide (CO2).
- Produced in bone marrow.
- Live ~120 days, then destroyed in the liver and spleen.
White Blood Cells (WBCs) / Leukocytes:
- ~4000-11000/mm³
- Various types with different functions.
- Crucial for defense against bacteria.
- Formed in bone marrow.
Platelets / Thrombocytes:
- ½ - ½ million/mm³
- Involved in blood clotting.
- Formed in bone marrow.

Blood Plasma

55% of blood volume
Straw-colored liquid
Composition:
- Water (92%)
- Proteins (6-8%): Albumin, globulins, fibrinogen
- Organic substances (2%): e.g., urea, glucose, hormones, enzymes
- Inorganic substances (1%): e.g., cations (Ca, Mg, Na, K), anions (Cl, HCO3)

Blood Cell Types (Elaboration)

Granulocytes:
- Neutrophils (most abundant, 50-70%): highly phagocytic, important for fighting infection.
- Eosinophils (2-4%): involved in allergic reactions and parasitic infections.
- Basophils (0.5-1%): involved in allergic reactions, release histamine and heparin.
Non-Granulocytes:
- Lymphocytes (20-40%): vital for immunity, antibody production.
  - B-cells: Produce antibodies
  - T-cells: Cell-mediated immunity
  - NK cells: Kill infected cells
- Monocytes (3-8%): migrate into tissues, turn into macrophages that engulf bacteria.

Additional Notes

Normal red blood cell count: 5.4 million/mm³ (males), 4.8 million/mm³ (females).
Bone marrow is the site of blood cell production (RBCs, WBCs, platelets)

This quiz covers the essential components of blood, including its cellular and plasma elements. Learn about the roles of red blood cells, white blood cells, platelets, and the composition of blood plasma. Understand how these elements contribute to overall health and bodily function.