The Heart ch 20

• Right Atrium: receives blood from systemic circuit through veins, is deoxygenated (blue). Blood then flows to Right Ventricle
• Right Ventricle: pumps blood into pulmonary circuit through pulmonary arteries. Blood is deoxygenated (blue). Blood then flows to the lungs
• Lungs: blood flows through for gas exchange, deoxygenated becomes oxygenated before flowing into the Left Atrium
• Left Atrium: receives blood from the pulmonary circuit through pulmonary veins that are oxygenated (red). Blood then flows to the Left Ventricle
• Left Ventricle: pumps blood into the systemic circuit through systemic arteries. Blood is oxygenated (red). Blood then flows to the rest of the body for a gas exchange, oxygenated becomes deoxygenated.
• Gas exchange: Blood either picks up carbon dioxide and drops off oxygen or it picks up oxygen and drops off carbon dioxide
• After blood flows through the rest of the body for a gas a exchange, blood returns back to the Right Atrium through systemic veins
• Pulmonary Circuit: Process of taking carbon dioxide from the lungs via blood for transport
• systemic circuit: the pathway of the blood through the body from the heart to transport oxygen to the body's organs
• Four chambers of the heart: Right atrium, Right ventricle, Left atrium, Left ventricle
• Pericarditis is the inflammation of the pericardial surfaces causing them to rub against each other. Caused by pathogens in the pericardium. May cause cardiac tamponade. Cardiac tamponade is the restricted movement of the heart due to excess fluid in the pericardial cavity.
• Heart wall consists of three distinct layers: the Visceral layer of serous pericardium, a.k.a. the epicardium, the myocardium, and the endocardium.
• Visceral layer of serous pericardium or epicardium covers the surface of the heart and is covered by the parietal layer of serous pericardium
• Myocardium: the middle layer of the heart that is made up of cardiac muscle tissue
• Endocardium: Covers the inner surfaces of the heart, made up of simple squamous epithelium and areolar tissue
• Cardiac skeleton is four dense bands of tough elastic tissue that encircle the heart valves and bases of the pulmonary trunk and aorta. It functions to stabilize the positions of the heart valves and ventricular muscle cells and to electrically insulate ventricular cells from atrial cells.
• Myocardial Infarction (MI), also known as a heart attack occurs when part of the coronary circulation becomes blocked and cardiac muscle cells die from a lack of oxygen. The death of affected tissue creates a nonfunctional area known as an infarct which most commonly results from severe coronary artery disease, CAD. Coronary Thrombosis, which is the formation of plaque is the most common cause of an MI
• The four different blood types are A, B, AB, and O.
• The cardiovascular system is made up of the heart, blood, and blood vessels.
• The heart beats approximately 100,000 times per day and pumps about 8000 liters of blood a day.
• Pulmonary circuit carries blood to and from gas exchange surfaces of the lungs
• Systemic circuit carries blood to and from the rest of the body.
• Arteries: a type of blood vessel that carries blood away from the heart. Arteries have thick walls and carry blood at high pressure from withstanding the pumping of the heart.
• Veins: type of blood vessel that carries blood back to the heart from the body.
• Capillaries: the smallest type of blood vessel that interconnect the smallest arteries and the smallest veins. Capillaries exchange dissolved gases, nutrients, and waste products with the blood and surrounding tissue.
• Three types of blood vessels: arteries, veins, and capillaries
• Pericardium: surrounds the heart. Made up of the outer serous pericardium and the inner serous pericardium which is made up of outer parietal layer and inner visceral layer (epicardium ).
• Pericardial Cavity: located between the parietal and visceral layers of the inner serous pericardium and contains pericardial fluid.
• Pericardial fluid: reduces friction within the pericardium by lubricating the epicardial surface allowing the membranes to glide over each other with each heart beat.
• Coronary sulcus: marks the border between the atria and the ventricles.
• Anterior inter-ventricular sulcus and posterior inter-ventricular sulcus mark the boundary between the left and right ventricles
• The coronary sinus empties into the right atrium
• The heart has two types of cardiac muscle cells: autorhythmic cells which control and coordinate heartbeat, and contractile cells which produce contractions that propel blood.
• The conducting system consists of specialized cardiac muscle cells that initiate and distribute electrical impulses that stimulate contraction.
• Autorhythmicity is the ability of cardiac muscle tissue to contract without neural or hormonal stimulation.
• Components of the conducting system include Pacemaker cells and conducting cells.
• Pacemaker cells are found in the SA (sinoatrial) node in the wall of right atrium and the AV (atrioventricular) node at the junction between atria and ventricles.
• Conducting cells are found in the internodal pathways of atria and in the AV bundle, bundle branches and purkinje fibers of ventricles.
• Pacemaker potential is the gradual depolarization of pacemaker cells.
• Pacemaker cells do not have a stable resting membrane potential.