Cardiovascular System Organs: Heart, Vessels, and Blood

Components

• Heart: Four-chambered muscular pump (right/left atria, right/left ventricles)
• Blood vessels:
  • Arteries: carry oxygenated blood away (except pulmonary artery)
  • Capillaries: exchange sites
  • Veins: return deoxygenated blood (except pulmonary veins)
• Blood:
  • Plasma (~55%): water, proteins, electrolytes, hormones
  • Red blood cells (erythrocytes): O₂ transport via hemoglobin
  • White blood cells (leukocytes): immunity
  • Platelets (thrombocytes): hemostasis

Functional Integration

Heart pumps → arteries distribute → capillaries exchange → veins return → heart receives. Pulmonary and systemic circuits run in series. Blood carries O₂, nutrients, waste, hormones, immune cells, clotting factors.