Heart Anatomy and Physiology Lecture Notes

Introduction

• Iconic Organ: The heart is a central, iconic organ in the body, often symbolized in culture.
• Function: Powers the circulatory system by transporting nutrients, oxygen, waste, etc.

Heart's True Function

• Pump: The heart's primary function is to act as a pump.
• Pressure Maintenance: Ensures high and low-pressure gradients necessary for blood flow.
• Blood Pressure: The strain on arteries as blood is moved (measure of heart's function).

Anatomy of the Heart

• Size and Location
  • About the size of two fists.
  • Located centrally in the chest, slightly tilted.
• Pericardium: Double-walled sac protecting the heart.
  • Fibrous Pericardium: Outer layer providing protection and anchoring.
  • Serous Pericardium: Inner layers (visceral and parietal) separated by fluid.

Heart Wall Structure

• Epicardium: Outer heart wall.
• Myocardium: Middle layer made of cardiac muscle tissue.
• Endocardium: Innermost epithelial tissue layer.

Heart Chambers and Valves

• Chambers: Divided into two sides and four chambers by septum.
  • Atria: Low-pressure, receive blood.
  • Ventricles: High-pressure, discharge blood.
• Valves: Ensure one-way blood flow (lub-dub sound).

Blood Flow and Circulation

• Pulmonary Circulation Loop: Right ventricle pumps blood to lungs; oxygen exchange occurs.
  • Pulmonary Arteries and Veins: Arteries carry deoxygenated, veins return oxygenated blood.
• Systemic Loop: Oxygenated blood from left ventricle to body, returns deoxygenated.
  • Aorta: Main artery distributing oxygen-rich blood.
  • Vena Cava: Main veins returning blood to heart.

Blood Pressure

• Systolic Pressure: Peak pressure during ventricular contraction.
• Diastolic Pressure: Pressure when ventricles are relaxed.
• Measurement and Importance: Indicates arterial and ventricular health.

Conclusion

• Heart's Role: Maintains pressure to circulate blood efficiently.
• Impact of Blood Pressure: Abnormal pressure can harm heart, lungs, brain, etc.

Credits

• Crash Course Team: Writers, directors, and contributors acknowledged for their efforts.