Blood Components and Their Functions

Main Components of Blood

• Red Blood Cells (RBCs):

  • Make up nearly half of the blood by volume.
  • Known as RBCs.
  • Function: Carry oxygen from the lungs to body tissues for cellular respiration.
  • Contain hemoglobin, which binds with oxygen to become oxyhemoglobin.
  • Oxygen is released into tissues as oxyhemoglobin splits back into hemoglobin and oxygen.
  • Unique Adaptations:
    • No nucleus, allowing more space for hemoglobin and oxygen.
    • Biconcave disc shape provides a large surface area for oxygen absorption.

• White Blood Cells (WBCs):

  • Comprise less than 1% of blood.
  • Crucial part of the immune system, defending against infections.
  • Types and Functions:
    • Phagocytosis: Engulf and consume microorganisms.
    • Antibody Production: Bind to pathogens and help destroy them.
    • Antitoxin Production: Neutralize toxins produced by pathogens.
  • Unique Feature: Have a nucleus.

• Platelets:

  • Small cell fragments, not actual cells, and lack a nucleus.
  • Role: Clot blood to prevent blood loss and entry of pathogens when cuts occur.

• Plasma:

  • Makes up just over half of the blood’s volume.
  • Appears as a pale straw-colored liquid.
  • Functions:
    • Carries RBCs, WBCs, and platelets.
    • Transports nutrients (glucose, amino acids), waste products (carbon dioxide, urea), hormones, proteins, antibodies, and antitoxins.

Blood Replacement

• Artificial Blood:

  • Comprised mainly of salt water.
  • Benefits: Increases blood volume, maintains circulation and heart function.
  • Limitation: Lacks RBCs, hence does not enhance oxygen transport.
  • Usability: Can replace only up to 1/3 of blood.

• Blood Transfusion:

  • Involves receiving donated blood containing real RBCs.
  • Essential for surviving major blood loss as it restores oxygen-carrying capacity.

Additional Information

• Adults typically have about five liters of blood.
• Blood loss from injury or surgery may necessitate blood replacement to ensure oxygen delivery to tissues.

Conclusion

Understanding the components of blood and their functions is crucial, especially in medical scenarios where blood loss needs to be managed through artificial blood or transfusions.