Biology Blood Components

Blood Components

• Blood consists of plasma (a watery liquid) and various cells, including red blood cells, white blood cells, and platelets.
• Plasma carries nutrients, carbon dioxide, urea, and waste products but does not transport oxygen.
• Red blood cells (about 5 billion per cubic cm) are biconcave, enhancing flexibility and surface area for efficient oxygen uptake in lungs.
• White blood cells are crucial for immune response, defending against infectious diseases.
• Platelets facilitate blood clotting by forming a mesh that traps red blood cells at injury sites.

Functions of Blood Components

• Red Blood Cells: Specialized for carrying oxygen to body cells, aided by hemoglobin.
• White Blood Cells: Protect the body by targeting and destroying pathogens.
• Platelets: Essential for initiating the clotting process to prevent excessive bleeding.
• Plasma: Transports digested food, hormones, and serves as a medium for other substances to travel in the blood.

Red Blood Cell Structure

• The biconcave shape allows red blood cells to squeeze through capillaries and increases surface area for gas exchange.
• The top side (outer surface) is adapted for optimal cell interaction with oxygen, while the bottom side (inner surface) holds hemoglobin for oxygen binding.

Oxygen and Nutrient Transport

• Oxygen moves from lungs to body cells during respiration.
• Carbon dioxide exits body cells, entering the blood, and then moves to the lungs for exhalation.
• Nutrients from digested food are taken from the small intestine to body cells via plasma, while urea is carried from the liver to kidneys for excretion.

Blood Testing

• Blood tests can diagnose various diseases and conditions.
• Sickle cell anemia results from faulty hemoglobin, causing red blood cells to become C-shaped and block blood flow, leading to pain and tissue damage.
• Malaria-causing protozoa live in red blood cells, feeding on hemoglobin and obstructing blood flow when they reproduce.
• Sleeping sickness protozoa also circulate in blood, causing multiple symptoms before affecting the brain.

Ideal Conditions for Microbial Growth

• Blood provides an abundant nutrient source, including glucose, fostering rapid microbial growth.
• The warm environment of the human body is conducive to the fast division of microorganisms present in the bloodstream.

Summary Tables

• Blood Component Functions:

  • Red blood cell: Oxygen transport.
  • White blood cell: Infection defense.
  • Platelet: Clotting facilitation.
  • Plasma: Nutrient and waste transport.

• Substance Transport:

  • Oxygen: Lungs to body cells.
  • Carbon dioxide: Body cells to lungs.
  • Digested food: Small intestine to body cells.
  • Urea: Liver to kidneys.