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Fundamentals of the Cardiovascular System

May 20, 2025

Cardiovascular System: Lecture Notes

Introduction

  • Cardiovascular: Relates to heart and blood vessels
    • 'Cardio' = Heart
    • 'Vascular' = Vessels
  • Components: Heart, blood vessels, blood

Main Functions

  1. Transport blood gases and nutrients
  2. Collect waste materials
  3. Maintain body temperature

Characteristics

  • Closed System: Blood is confined to vessels, separate from interstitial fluid

Blood Flow Process

  • Heart pumps blood into large vessels → branch into smaller ones → lead to organs
  • Nutrient and waste exchange by diffusion between blood and interstitial fluid

Circulatory Loops

  • Systemic Loop:
    • Oxygenated blood from heart to tissues/organs
    • Deoxygenated blood back to heart
  • Pulmonary Loop:
    • Deoxygenated blood from heart to lungs
    • Oxygenated blood back to heart
  • Both loops start and end at the heart, carrying opposite types of blood

Heart Anatomy and Blood Flow

  • Orientation: Heart diagram is like viewing someone else's heart (left/right side swapped)

Chambers and Flow

  • Receiving Chambers:
    • Right Atrium: Receives deoxygenated blood via superior and inferior vena cava
    • Left Atrium: Receives oxygenated blood from pulmonary veins
  • Pumping Chambers:
    • Right Ventricle: Pumps deoxygenated blood to lungs via pulmonary artery
    • Left Ventricle: Pumps oxygenated blood to body via aorta

Valves

  • Tricuspid Valve: Between right atrium and right ventricle
  • Pulmonary Semi-Lunar Valve: From right ventricle to pulmonary artery
  • Bicuspid/Mitral Valve: Between left atrium and left ventricle
  • Aortic Semi-Lunar Valve: From left ventricle to aorta

The Aorta and Arteries

  • Aorta: Major artery leaving the heart
    • Aortic Arch: Bends around the heart, branches into coronary arteries
    • Additional branches supply head, neck, arms, and upper body
    • Descending Aorta: Supplies lower body

Comparison with Other Animals

  • Amphibians: Three-chambered heart, mixed blood
  • Turtles: Three-chambered heart with partial septum, reduced mixing
  • Birds and Mammals: Four-chambered heart, complete septum, no mixing of blood
    • Guarantees separation between oxygenated and deoxygenated blood

Diagram Instructions

  • Tape provided heart diagram into lab notebook
  • Label the diagram appropriately

These notes provide a foundational understanding of the cardiovascular system, focusing on the function and structure of the heart and the circulatory loops.