This is a painting I made in the winter of 2005. I am fascinated at times by this muscle. That beats, and pumps nutrients and emotions to nearly every cell in my body. This heart painting seems to be overweight, which hopefully is not a relfelction of my own heart.
OXYGENATION Just a quick review.Deoxygenated blood goes into the Right Atrium to Right Ventricle-- to the lungs to pick up O2.Oxygenated blood then goes from the lungs into the RA to RV to Aorta to body--In other words…the RV pumps blood to the pulmonary circulation( to the lungs) .The LV pumps blood to the systemic circulation( to the body.)The pump, that is the myocardial pumping action of the heart is essential to maintaining oxygen delivery.The 4 chambers of the heart fill w/ blood during diastole and empty during systole.In other words…systole (contraction) is when the blood is ejected from the ventricles.The heart muscle fibers are stretchable…they have contractile properties. This is Starlings law..The stretch is related to the contraction…Think of the rubber band, the greater the stretch the farther it will go…The greater the stretch the greater the contraction…Remember…The more stretch the greater the contraction, the greater the stroke volume….In healthy hearts only.The pumps effectiveness is decreased by….CAD and CHF…these lead to diminished stroke volume.The LV does most of the pumping, most of the work.
Blood flow through the heart.Unidirection is maintained by the heart valves.Mitral valve is the left AV valve.Tricuspid is the right AV valve.S1 the first heart sound is heard because of the mitral and tricuspid valves open and blood then flows into the ventricles. So..the ventricles are filled with blood and the aortic and pulmonary semi lunar valves open letting the blood flow from the filled ventricles out to the aorta (goes to body, systemic) and to the pulmonary artery (goes to the lungs)…The valves Pulm. and aortic (semi lunar) valves then close- this is S2, the second heart sound.
Coronary Artery Circulation. This is a part of the systemic circulation.Coronary Arteries supply the heart with the O2 that it needs.The right and left coronary arteries stem from the aorta.Just as the left side of the heart does most of the pumping work….the left coronary arteries have the most blood supply and they feed the left ventricle part of the heart.Right Coronary Artery…supplies the posterior aspect of the septum, posterior papillary muscle, Sinus and AV nodes, and the inferior wall of the LV.Left Coronary Artery….LAD-left anterior descending, supplies the anterior LV wall, Anterior papillary muscle, Anterior interventricular septum which supplies the conduction system of the heart- bundle of his, and bundle branches……25% of MI ( heart attack) is a problem with LAD to the anterior wall of the LV. LAD also supplies the left ventricular apexCircumflex…Comes off of the left coronary arteries, wraps around the back, supplies the left atrium, posterior left ventricle, and posterior septum.
Systemic Circulation. Review.-O2 blood from the Left Ventricle to the Aorta to the body…..In the body it travels through arteries to the tissues and organs..it goes from big arteries to smaller arteries to arterioles to capillaries. This is all oxygenated blood.Then at the capillaries gases, nutrients are exchanged and the tissues become oxygenated. The waste product CO2 is carried off through the venues to veins to larger veins to the heart. This is all deoxygenated blood…it gets back to the heart to the RA….to the RV…to the lungs to drop of the CO2 and pick up O2..Then back to the heart again with now oxygenated blood to go to the LA to the LV to the Aorta to the body etc……..again and again and again….
Hemostasis: Process that prevents blood loss from vessels that are intact and stops blood loss from vessels that are severed or injured.Intact vessels are protected by platelets. These platelets nurture the endothelium and maintain the integrity of the vessel wall.
Primary Hemostasis: Constriction of the severed blood vessel. Platelets aggregate at the site-stick together forming an unstable hemostatic plug.
Secondary Hemostasis: coagulating factors are converted into active forms. This happens at the site of injury. The process in the end leads to the formation of fibrin. Fibrin reinforces the plug and anchors it. Factor X is activated-- Prothrombin-- Thrombin-- Fibrinogen -- Fibrin Clot.2 pathways that are needed: Intrinsic pathway is slow and it happens when collagen that lines blood vessels is exposed. The sequence of clotting is started and ends with a clot, which is fibrin. The extrinsic pathway is fast, it is activated by tissue injury and thromboplastin is released by the tissues.