Cardiovascular System

Functions of the Cardiovascular System

• Cardiovascular System: Comprises the heart, blood vessels, and blood.

  • Structures work in unison to distribute blood efficiently.

  • Blood: Connective fluid tissue that:

    • Transports oxygen and nutrients to tissues.

    • Carries waste back to the kidneys and CO2 to the lungs.

    • Plays a crucial role in the immune system.

Structures of the Cardiovascular System (Part 1)

Major Structures

• Heart:

  • Hollow, muscular organ located in the thoracic cavity between the lungs.

  • Approximately the size of a fist.

  • Functions as a powerful pump maintaining blood flow throughout the body.

  • Apex: The lower tip of the heart.

Structures of the Cardiovascular System (Part 2)

Pericardium

• Double-walled sac enclosing the heart:

  • Parietal pericardium: Fibrous protective layer.

  • Pericardial fluid: Lubricates to prevent friction during heartbeats.

  • Visceral pericardium: Inner layer, forming the outer layer of the heart.

Structures of the Cardiovascular System (Part 3)

Walls of the Heart

• Epicardium: Outer layer.

• Myocardium: Middle layer, thickest and muscular.

• Endocardium: Inner lining, directly contacts blood; nourished by coronary arteries.

Structures of the Cardiovascular System (Part 4)

Chambers of the Heart

• Atria:

  • Upper chambers receiving blood.

  • Divided by interatrial septum.

• Ventricles:

  • Lower chambers pumping blood.

  • Divided by interventricular septum; thicker walls than atria.

Structures of the Cardiovascular System (Part 5)

Valves of the Heart

• Tricuspid Valve: Between right atrium and ventricle.

• Pulmonary Valve: Between right ventricle and pulmonary artery.

• Mitral Valve: Between left atrium and ventricle.

• Aortic Valve: Between left ventricle and aorta.

Blood Circulation

Pulmonary Circulation

• Blood flow between the heart and lungs.

  • Pulmonary arteries: Carry deoxygenated blood to lungs.

  • Pulmonary veins: Carry oxygenated blood to left atrium.

Systemic Circulation

• Blood flow to body parts except the lungs.

  • Oxygenated blood: Flows from left ventricle into arterial circulation.

  • Deoxygenated blood: Flows into right atrium before returning to the heart.

Cardiovascular Physiology

The Heartbeat

• Sequential contraction and relaxation.

  • Electrical impulses: Determine heart rate and rhythm.

  • Conduction system:

    • SA Node: Initiates heartbeat.

    • AV Node: Receives impulses from SA node.

    • Bundle of His: Coordinates ventricles' contractions.

Electrocardiogram (EKG)

• Represents heart's electrical activity:

  • P wave: Atrial contraction.

  • QRS complex: Ventricular contraction.

  • T wave: Ventricular recovery.

Blood Vessels (Part 1)

Arteries

• Carry** oxygen-rich blood** away from the heart.

• Three layers wall structure; include:

  • Aorta: Largest artery, originating from left ventricle.

  • Carotid arteries: Supply blood to the head.

  • Arterioles: Small branches leading to capillaries.

Blood Vessels (Part 2)

Capillaries

• Smallest blood vessels; single-cell thickness.

• Facilitate the exchange of oxygen, nutrients, and waste.

Blood Vessels (Part 3)

Veins

• Return oxygen-poor blood to the heart; thinner walls than arteries.

• Include venules and two major veins:

  • Superior vena cava: From upper body.

  • Inferior vena cava: From lower body.

Blood Composition

Components of Blood

• Liquid Plasma: 55% of blood; contains nutrients and waste products.

• Formed Elements: 45% including:

  • Erythrocytes (RBCs), Leukocytes (WBCs), Thrombocytes (platelets).

  • Each type plays crucial roles in immune response, clotting, and transport.

Blood Types

• Classified by presence/absence of antigens; four types: A, AB, B, O.

• Rh Factor: Determines positive or negative blood types crucial for transfusions.

Pathology of the Cardiovascular System

Disorders of the Heart

• Congenital heart defects: Abnormalities present at birth.

• Coronary artery disease (CAD): Atherosclerosis of coronary arteries.

• Ischemia: Insufficient oxygen supply due to blood flow restriction.

• Myocardial infarction: Heart attack caused by coronary artery blockage.

Heart Failure

• Can lead to fluid retention, arrhythmias, and decreased heart efficiency.

Cardiac Arrhythmias

• Includes asystole, bradycardia, tachycardia, and fibrillation.

Diagnostic Procedures

• Angiography: Imaging blood vessels.

• Cardiac catheterization: Diagnostic passage of catheter into the heart.

• ECG: Monitors heart's electrical activity.

Treatment Procedures

• Medications: Includes antihypertensives, anticoagulants, and antiarrhythmics.

• Surgery: Coronary bypass, valve replacement, and angioplasty procedures.

Abbreviations Related to Cardiovascular System

• Examples include EKG, CABG, MVP, and A-fib.