Cardiovascular System Notes

  1. Overview

    • The cardiovascular system is responsible for transportation of substances throughout the body.

  2. Components of the Cardiovascular System

    • Organs:

      • Heart

      • Blood Vessels

      • Arteries

      • Veins

      • Capillaries

    • Tissue:

      • Blood

  3. Function of the Cardiovascular System

    • Transportation of various substances throughout the body, including:

      • Oxygen and Carbon Dioxide (O2 & CO2)

      • Nutrients and Wastes

      • Hormones, etc.

    • Blood carries these substances.

    • The heart pumps blood through vessels.

  4. Anatomy of the Heart

    • Located between the lungs in the thoracic cavity.

    • Within the inferior mediastinum, which is the middle cavity of the thorax.

    • Orientation:

      • Base (superior end) points towards the right shoulder.

      • Apex (inferior end) points toward the left hip and rests on the diaphragm.

  5. Other Characteristics of the Heart

    • Approximately the size of a closed fist.

    • Weighs less than a pound.

    • Beats about 2.5 billion times in a lifetime.

  6. Pericardium

    • The heart is surrounded by a serous membrane called the pericardium or pericardial sac.

    • Secretes serous fluid to reduce friction.

  7. Heart Wall Layers

    1. Epicardium or visceral pericardium

    2. Myocardium – thick muscular layer

    3. Endocardium lines heart chambers

  8. Myocardium Details

    • Thick bundles of cardiac muscle that are twisted into ring-like arrangements.

    • This is the layer of the heart wall that actually contracts.

  9. Myocardium is Cardiac Muscle

    • Cardiac muscle has:

      • Mitochondria

      • Myofibrils

      • Intercalated discs

  10. Superficial Heart Anatomy (Anterior)

    • Key structures include: