Cardiovascular System

• The components of the Cardiovascular System include the Heart, Blood Vessels, Veins, Arteries, Blood, Lymphatics.
• The Heart rests on the diaphragm, near the midline of the thoracic cavity and lies in the mediastinum.
• The size of the Heart is that of a fist and weighs less than 1 lb.
• Arrhythmia refers to abnormal heart rhythms.
• Bradycardia is a condition where the heart rate is abnormally slow.
• Tachycardia is a condition where the heart rate is abnormally fast.
• Ventricular Fibrillation is a condition where the ventricles fibrillate, or quiver, instead of contracting normally.
• Atrial Fibrillation is a condition where the atria fibrillate, or quiver, instead of contracting normally.
• Atrial septal Defect (ASD) is a congenital heart defect that is a hole in the heart, allowing oxygenated blood to mix with deoxygenated blood.
• Tetralogy of Fallot is a congenital heart defect that involves a merged aorta, an enlarged right ventricle, and interventricular septal defect, and pulmonary stenosis.
• The location of the Heart is between lungs in the thoracic cavity.
• The orientation of the Heart is with the apex (bottom) towards the left side (ventricle) and the base (top) is the posterior surface (atria).
• The anterior surface of the Heart is deep to the sternum and ribs.
• The inferior surface of the Heart is between the apex and the right border.
• The right border of the Heart faces the lungs.
• The left border of the Heart faces the left lung.
• Ventricular contraction increases pressure in the ventricle vs the arteries, causing the semilunar valves to open.
• Ventricles relax, allowing blood to flow back toward the heart, which fills the valve cusps, causing the semilunar valves to close tightly.
• Stenosis refers to a narrowed opening.
• Mitral stenosis is caused by scar formation or a congenital defect that causes narrowing of the mitral valve.
• Incompetence/insufficiency is the inability of a valve to close completely.
• Mitral insufficiency is the backflow of blood from the left ventricle into the left atrium.
• Mitral valve prolapse is the most common heart valve disorder.
• Rhematic Fever is an acute systemic inflammatory disease caused by Streptococcus pyogenes (Strep throat).
• Cardiac muscle has a single centrally located nucleus, branching cells, is rich in mitochondria, striated (actin and myosin), uses Ca 2+ and ATP for contractions, and has intercalated disks that connect cells.
• The pulmonary circuit carries blood from heart to lungs, where it is oxygen-poor and carbon dioxide-rich.
• The systemic circuit carries blood from heart to body, where it is oxygen-rich and carbon dioxide-poor.
• Blood flow through the heart involves the tricuspid valve, right atrium, right ventricle, pulmonary semilunar valve, pulmonary trunk, pulmonary arteries, lungs, pulmonary veins, left atrium, bicuspid valve, left ventricle, aortic semilunar valve, aorta, and body.
• Blood supply to the heart involves the coronary arteries, which supply blood to the heart wall and originate from the base of the aorta (above the aortic semilunar valve), and the cardiac veins, which drain blood from the cardiac muscle.
• The Heart generates blood pressure, regulates blood supply, routes blood, and ensures one way blood flow.
• Coronary sinus is a large vein located within the coronary sulcus into the right atrium, returning blood to the right atrium.
• Myocardial ischemia is the partial obstruction of blood flow in the coronary arteries, resulting in hypoxia.
• Angina pectoris is severe pain that usually accompanies myocardial ischemia and may radiate.
• Myocardial infarction is the death of tissues due to interrupted blood supply, resulting in heart tissue being replaced by fibrous tissue and may disrupt the conduction system of the heart and cause sudden death by triggering ventricular fibrillation.
• Treatment for myocardial infarction includes thrombolytic (clot-dissolving) agent or performing coronary angioplasty or coronary artery bypass grafting.
• Myocardial infarction, also known as heart attack, is usually due to atherosclerosis.
• Atherosclerosis is the build-up of plaque in blood vessels, coming from bad cholesterol (LDL-C) and good cholesterol prevents it by extraction of fats (HDL-C).
• Heart procedures include angioplasty, which opens blocked blood vessels, stent, structures inserted to keep vessels open, and bypass, which reroutes blood away from blocked arteries.
• The heart has an inherent electrical activity, composed of the SA node, AV node, AV bundle, bundle (Right and Left) branches, and Purkinje fibers.
• The sympathetic nervous system and parasympathetic nervous system are part of the nervous system.