Circulatory System Overview

Introduction

• Understanding the circulatory system and its functions.
• Focus on the heart as part of this organ system.

Components of the Circulatory System

• Organs involved:
  • Heart
  • Blood vessels
  • Blood
• Functions:
  • Transport substances (oxygen, nutrients, waste products).
  • Blood vessels direct blood flow.
  • Heart pumps to maintain blood flow.

Double Circulatory System

• Pulmonary Circuit:
  • Blood flows from heart to lungs and back.
  • Purpose: Oxygenate blood.
• Systemic Circuit:
  • Blood flows from heart to body tissues and back.
  • Purpose: Distribute oxygenated blood to the body.

Structure of the Heart

• Chambers:
  • 4 chambers: 2 Atria (top), 2 Ventricles (bottom).
  • Atria: Right atrium, Left atrium.
  • Ventricles: Right ventricle, Left ventricle.
• Valves:
  • Atrioventricular valves ensure one-way blood flow from atria to ventricles.
  • Right and Left atrioventricular valves control flow between respective atria and ventricles.
• Muscle Wall:
  • Left ventricle has a thicker wall to pump blood throughout the body.

Blood Vessels of the Heart

• Vena Cava:
  • Largest vein; carries deoxygenated blood to the heart.
• Pulmonary Artery:
  • Carries deoxygenated blood from heart to lungs.
• Pulmonary Vein:
  • Carries oxygenated blood from lungs to heart.
• Aorta:
  • Largest artery; carries oxygenated blood from heart to body.

Blood Flow Cycle

• Deoxygenated blood enters right atrium via vena cava.
• Right atrium contracts, moving blood to right ventricle.
• Right ventricle contracts, pushing blood into pulmonary artery to lungs.
• Oxygenated blood returns to left atrium via pulmonary vein.
• Left atrium contracts, sending blood to left ventricle.
• Left ventricle contracts, pumping blood into aorta to body tissues.
• Cycle repeats.

Coronary Arteries

• Supply heart muscle with oxygenated blood.
• Branch off from the aorta.
• Blockage can lead to coronary artery disease or heart attack.

Additional Resources

• Videos, questions, flashcards, and study progress tracking available at Cognito.org.