Two Main Coronaries

carotid artery comes directly from the aortic arch. In the cat, both common carotid arteries branch from the

4. left ventricle 5. superior vena cava 6. inferior vena cava 7. ascending aorta 8. aortic arch 9. brachiocephalic artery 10. left common carotid artery 11. left subclavian artery 12. pulmonary trunk 13. right pulmonary artery 14. left pulmonary artery 15. ligamentum arteriosum 16. right pulmonary veins 17. left pulmonary veins 18. right coronary artery 19. anterior cardiac vein t s w x v 20. left coronary artery 21. circumflex artery 22. anterior

When the left atrium is filled with blood, the heart contracts and the blood passes through the bicuspid valve and into the left ventricle.

It begins at the base of the heart’s right ventricle and is approximately 3 cm in diameter and 5 cm in length (Yahoo Health, 2012). It then splits into the left and right pulmonary arteries. The right pulmonary artery delivers oxygen depleted blood to the right lung. From the right pulmonary artery I have made it to the right lung. Once in the lung I will travel South West to reach the lower lobe of the right lung.

For this myocardial infarction, the right coronary artery was blocked. The parts of the heart that were affected by this blockage was the right atrium, the right ventricle, the interventricular septum, the Sinoatrial node and the AV node, and some parts of the left atrium and ventricle. These parts were affected because the right coronary artery supplies blood to these parts of the heart; since there was a blockage the blood was not able to continue through the right coronary arteries into its branches, which are the sinoatrial nodal artery, the right marginal branch, the posterior interventricular branch, and the atrioventricular nodal artery (Gest).

Likewise, Blood flows from the right atrium to the right ventricle, and then is pumped to the lungs to receive oxygen. From the lungs, the blood flows to the left atrium, then to the left ventricle, forming the complete circulation.

In a normal human being the heart correctly functions by the blood first entering through the right atrium from the superior and inferior vena cava. This blood flow continues through the right atrioventricular valve into the right ventricle. The right ventricle contracts forcing the pulmonary valve to open leading blood flow through the pulmonary valve and into the pulmonary trunk. Blood is then distributed from the right and left pulmonary arteries to the lungs, where carbon dioxide is unloaded and oxygen is loaded into the blood. The blood is returned from the lungs to the left

to the right and left lung. After entering the lungs, the branches subdivide, finally emerging as

Heart failure can be attributed to either right sided, left or both. Left-sided heart failure is of two types, systolic failure and diastolic failure. Systolic failure is the when the left ventricle loses its ability to contract normally. The heart cannot pump with enough force to push enough blood into circulation. Diastolic failure is when the left ventricle loses its ability to relax normally. Which results in the heart not being able to fill with blood during the resting period. Both result in a decrease in cardiac output. (AHA, 2012). A decrease in the cardiac output into the systemic circulation causes blood to accumulate in the left ventricle, left atrium, and pulmonary circulation. This increase

Another word used to describe a heart attack is myocardial infarction, cardiac infarction and coronary thrombosis. A heart attack is the death of a part of the heart caused by the loss of blood supply. The blood supply is usually gone due to a coronary artery being blocked by a blood clot. When a part of a heart artery breaks a blood clot forms around the piece. This blood clot can block the blood flow through the heart muscle. When the heart muscle needs oxygen it is called ischemia. When damage of a part of the heart muscle happens it’s called a heart attack. During a heart attack damage occurs depending on the size of the area blocked by the blood clot as well as the time between the actual heart attack and the treatment. Even though the heart may be hurt, the rest of the organs work with no problems. However, it will not pump as much blood as it used to in order to supply the same amount of blood to all of the parts of the body.

A heart attack occurs when an artery that supplies blood to the heart becomes blocked. The loss of oxygen and nutrients damage the heart's muscle tissue, causing the remaining healthy tissue to pump even harder to keep up.

The left side of the heart, has the left atrium and ventricle that takes in oxygenated blood from the lungs and pumps it out of the aorta.

These two left arteries feed the front and left side of the heart. The division of the left coronary artery is the reason why doctors usually refer to three main coronary arteries.

Both the right and left atrium contract causing blood to flow though the two valves, and then into the left ventricle. The left ventricle pumps blood into the systemic circulation through the aorta. This systemic circulation system is much bigger than the pulmonary circulation system, which is why the left ventricle is so big. The blood on the left side of the heart is oxygenated. It becomes oxygenated when the deoxygenated blood passes through the right atrium and then flows into the left ventricle. It is then pumped along the pulmonary artery into the lungs where it is oxygenated. It then travels through the pulmonary veins back into the heart. It enters through the left atrium and then travels to the left ventricle. This process is repeated over and over again, to make blood continuously flow through the heart, lungs and body. This process ensures that there is always enough oxygen for the body to work

Right ventricular infarction may occur with occlusion of the right coronary artery. With infarct affect the posterior wall of the left ventricle and the posterior interventricular septum, they extend to the right ventricular wall in 15 to 30% of cases. The central venous pressure may be elevated markedly if acute right ventricular failure develops. Low right ventricular output causing shock often responds well to vigorous fluid therapy but poorly to vasodilators. Infusions raise both right and left ventricular filling pressures. The diagnosis of right ventricular infarction is difficult but may be established by right sided ECG leads and echocardiographic studies (Bullock, 1996).