Study Notes on the Cardiovascular System

CHAPTER 5: THE CARDIOVASCULAR SYSTEM

Overview of Structures, Combining Forms, and Functions of the Cardiovascular System

  • The cardiovascular system comprises the heart, blood vessels, and blood.
  • Major Structures:
    • Heart: Primary function is to receive blood from the veins and pump blood into the arteries.
    • Blood Vessels: Transport blood to and from all areas of the body (angi/o, vas/o).
    • Arteries (arteri/o): Transport blood away from the heart.
    • Capillaries (capill/o): Allow for nutrient and waste exchange between blood and cells.
    • Veins (phleb/o, ven/o): Return blood from all body parts to the heart.
    • Blood: (hem/o, hemat/o) Carries oxygen and nutrients to cells and removes waste.

Vocabulary Related to the Cardiovascular System

Word Parts
  • angi/o: blood or lymph vessel
  • aort/o: aorta
  • arteri/o: artery
  • ather/o: plaque, fatty substance
  • brady: slow
  • cardi/o: heart
  • -crasia: a mixture or blending
  • -emia: blood, blood condition
  • erythr/o: red
  • hem/o, hemat/o: blood, relating to blood
  • leuk/o: white
  • phleb/o: vein
  • tachy: fast, rapid
  • thromb/o: clot
  • ven/o: vein
Medical Terms
  • ACE inhibitor: Medication that inhibits the Angiotensin-Converting Enzyme to lower blood pressure.
  • anemia: (ah-NEE-mee-ah) A deficiency of red blood cells.
  • aneurysm: (AN-you-rizm) A dilation of a blood vessel due to weakness in the vessel wall.
  • angina: (an-JIGH-nuh) Chest pain due to inadequate blood flow to heart muscle.
  • angioplasty: (AN-jee-oh-plas-tee) Surgical procedure to widen narrowed blood vessels.
  • anticoagulant: (an-tih-koh-AG-you-lant) Medication that prevents blood clots.
  • arrhythmia: (ah-RITH-mee-ah) Irregular heartbeat.
  • atherosclerosis: (ath-er-oh-skleh-ROH-sis) Hardening and narrowing of arteries due to plaque buildup.
  • heart failure: The inability of the heart to pump sufficient blood to meet the body's needs.

Learning Objectives

Upon completion of this chapter, you should be able to:

  1. Describe the heart in terms of chambers, valves, blood flow, heartbeat, and blood supply.
  2. Differentiate among the three types of blood vessels, and describe their major functions.
  3. Identify the major components of blood and their functions.
  4. State the difference between pulmonary and systemic circulation.
  5. Define, spell, and pronounce terms related to cardiovascular pathology and procedures.

Functions of the Cardiovascular System

  • The cardiovascular system efficiently pumps blood to all tissues, transporting oxygen and nutrients while removing carbon dioxide and waste products.
  • Blood also plays essential roles in the immune and endocrine systems.

Structures of the Cardiovascular System

The Heart
  • A hollow, muscular organ located in the thoracic cavity, between the lungs, about the size of a fist. It maintains blood flow throughout the body.
The Pericardium
  • A double-walled membranous sac that encloses the heart, comprised of:
    • Parietal pericardium: Outer layer providing protection.
    • Visceral pericardium: Inner layer also known as epicardium.
    • Pericardial fluid: Lubricates the heart to reduce friction.
Walls of the Heart
  • Composed of three layers:
    • Epicardium: External layer.
    • Myocardium: Thick, muscular middle layer responsible for heart contractions.
    • Endocardium: Inner lining that contacts blood.
Blood Supply to the Myocardium
  • Supplied by coronary arteries, which provide oxygen-rich blood.
  • Wastes are removed via coronary veins.
Chambers of the Heart
  • Atria: Upper chambers that receive blood (divided by interatrial septum).
  • Ventricles: Lower chambers that pump blood (thicker walls due to their pumping function, divided by interventricular septum).
Valves of the Heart
  • Control blood flow through the heart:
    • Tricuspid valve: Between right atrium and right ventricle.
    • Pulmonary valve: Between right ventricle and pulmonary artery.
    • Mitral valve (bicuspid): Between left atrium and left ventricle.
    • Aortic valve: Between left ventricle and aorta.
Blood Circulation
  1. Pulmonary circulation: Blood flows between the heart and lungs.
    • Pulmonary arteries carry deoxygenated blood to the lungs; pulmonary veins carry oxygenated blood to the heart.
  2. Systemic circulation: Blood flows to and from all body tissues.
    • Oxygenated blood exits the heart and is delivered to tissues; deoxygenated blood returns to the heart.
Heartbeat
  • The contraction and relaxation cycle of the heart, regulated by electrical impulses from nerves. The sinoatrial (SA) node acts as the heart's natural pacemaker, followed by the transmission of impulses through the atrioventricular (AV) node and the bundle of His, leading to Purkinje fibers that control ventricular contraction.
  • Electrical waves are monitored via an electrocardiogram (ECG/EKG).
Types of Blood Vessels
  1. Arteries: Carry blood away from the heart; composed of three layers for elasticity and strength.
  2. Capillaries: Microscopic vessels where nutrient and gas exchange occurs; one cell thick.
  3. Veins: Return blood to the heart, equipped with valves to prevent backflow; thinner walls than arteries.
    • Venae cavae: Major veins returning blood to the heart (superior and inferior).

Blood

Components of Blood
  • Plasma: 55% of blood, a fluid that contains water, proteins, nutrients, and waste products.
  • Formed elements (45%): Includes:
    • Erythrocytes (red blood cells): Transport oxygen via hemoglobin.
    • Leukocytes (white blood cells): Defend against infection.
    • Includes neutrophils, basophils, eosinophils, lymphocytes, and monocytes.
    • Thrombocytes (platelets): Aid in clotting blood.
Blood Types
  • Blood types determined by antigens on red blood cells; major types include A, B, AB, and O.
  • Rh factor: Presence (+) or absence (-) of the Rh antigen affects transfusions and pregnancies.
Blood Disorders
  • Anemia: Reduction in red blood cells.
  • Leukemia: Increase in abnormal white blood cells.
  • Hypertension: High blood pressure.
  • Hypotension: Low blood pressure.

Medical Specialties Related to Cardiovascular System

  • Cardiologist: Specializes in heart disorders.
  • Hematologist: Specializes in blood disorders.
  • Vascular surgeon: Focuses on blood vessel disorders.
  • Telemetry nurse: Monitors vital signs using technology.

Pathology of the Cardiovascular System

  1. Congenital heart defects: Structural abnormalities present at birth.
  2. Coronary artery disease (CAD): Reduced blood flow to heart muscle due to atherosclerosis.
  3. Heart failure: Chronic condition where the heart cannot pump enough blood.
  4. Arrhythmias: Disorders of heart rhythm.

Diagnostic Procedures of the Cardiovascular System

  • Tests such as angiography, cardiac catheterization, and electrocardiography are used to evaluate cardiovascular function.

Treatment Procedures

  • Include medications like antihypertensives, anticoagulants, and surgical procedures like angioplasty and bypass grafts.

Abbreviations Related to the Cardiovascular System

  • A-fib: Atrial fibrillation
  • CAD: Coronary artery disease
  • MI: Myocardial infarction
  • HTN: Hypertension
  • PAD: Peripheral artery disease