Cardiovascular System Overview

Introduction

• Understanding the heart's sounds (lub-dub) related to the cardiovascular system.
• Focus on human anatomy and physiology, specifically the cardiovascular system.

Blood Composition and Function

• Blood Appearance:
  • Human blood is always red (dark or light shade).
  • Blue/green vein appearance is an optical illusion.
• Functions:
  • Maintains pH, temperature, and osmotic pressure (homeostasis).
  • Delivers hormones, nutrients, and gases throughout the body.
• Components:
  • Plasma: Liquid portion with water, proteins, salts, lipids.
  • Red Blood Cells: Transport gases.
  • White Blood Cells: Fight infections.
  • Platelets: Aid in blood clotting.
  • Hemoglobin: Iron-rich protein giving blood its red color.

Circulatory System

• Arteries: Carry blood away from the heart (oxygen-rich).
• Veins: Return blood to the heart (oxygen-poor).
• Pulmonary Circulation Exception:
  • Pulmonary arteries carry oxygen-poor blood.
  • Pulmonary veins carry oxygen-rich blood.
• Capillaries: Deliver oxygen to tissues and remove carbon dioxide.

Heart Anatomy

• Orientation:
  • Right side is deoxygenated; left side is oxygenated.
  • Chambers:
    • Right/Left Atrium (thinner walls).
    • Right/Left Ventricle (thicker walls).
  • Valves: Prevents backward blood flow.

Blood Flow Through the Heart

• Deoxygenated Blood Pathway:
  • Enters through vena cava (inferior or superior).
  • Right atrium → tricuspid valve → right ventricle → pulmonary valve → pulmonary artery.
• Oxygenated Blood Pathway:
  • Enters through pulmonary veins.
  • Left atrium → mitral valve → left ventricle → aortic valve → aorta.

Coronary Circulation

• Coronary Arteries: Supply oxygen to the heart.
• Coronary Veins: Return deoxygenated blood to the heart.

Heart Electrical Conduction System

• SA Node: Primary pacemaker (60-100 bpm).
• AV Node: Secondary pacemaker (40-60 bpm, delays impulse).
• Bundle of His: Transmits signals to ventricles.
• Purkinje Fibers: Initiate ventricular contraction (20-40 bpm).
• Mnemonic: Strong Arteries Benefit Body's Performance (SA, AV, Bundle branches, Purkinje fibers).

ECG Basics

• Isoelectric Line: Baseline with no net electrical movement.
• P Wave: Atrial depolarization (contraction).
• QRS Complex: Ventricular depolarization (contraction).
• T Wave: Ventricular repolarization (relaxation).
• Atrial Repolarization: Occurs during QRS complex, obscured by ventricular contraction.

Blood Pressure

• Systolic Pressure: Peak pressure during heart contraction.
• Diastolic Pressure: Lowest pressure during relaxation.
• Typical Range: 120/80, varies with age/individual.

Conclusion

• Understanding the cardiovascular system is crucial for healthcare professions.
• Further resources are available on NurseChunkStar.com.