Anatomy Of The Heart Quiz

The pulmonary artery is the blood vessel that carries blood from the right ventricle to the lungs. It is responsible for transporting deoxygenated blood from the heart to the lungs, where it picks up oxygen and gets rid of carbon dioxide. This oxygenated blood is then returned to the heart to be pumped to the rest of the body. The pulmonary artery is unique in that it is the only artery in the body that carries deoxygenated blood.

During ventricular contraction, the AV valves close in order to prevent the backflow of blood from the ventricles to the atria. This is important because the AV valves separate the atria from the ventricles, and their closure ensures that blood flows in the correct direction, from the atria to the ventricles and then out to the rest of the body. If the AV valves did not close during ventricular contraction, blood could flow back into the atria, reducing the efficiency of the heart's pumping action and potentially causing congestion in the atria.

The venae cavae are large veins that carry deoxygenated blood from the body back to the heart. They empty this blood into the right atrium, which is one of the four chambers of the heart. The right atrium then contracts and pumps the blood into the right ventricle, which then pumps the blood to the lungs for oxygenation. Therefore, the correct answer is the right atrium.

The left ventricle is responsible for pumping oxygenated blood to the rest of the body, and it does so by ejecting blood into the aorta. The aorta is the largest artery in the body and carries oxygen-rich blood away from the heart to supply all the organs and tissues. Therefore, it is the correct answer for the question.

The pericardial space is a cavity located between the epicardium (outer layer of the heart) and the parietal pericardium (outer layer of the pericardium). It contains a small amount of fluid that helps lubricate the movement of the heart. This space allows the heart to move and beat without friction against the surrounding structures.

The terms actin, myosin, and sarcomeres are all related to muscle contraction. Actin and myosin are proteins involved in the sliding filament theory of muscle contraction, while sarcomeres are the basic contractile units of muscle fibers. The myocardium is the muscular layer of the heart that contracts to pump blood, making it the most appropriate answer in this context. The other options, such as the left ventricle, right ventricle, pericardium, and precordium, are not specifically related to muscle contraction.

The purpose of the right heart is to pump blood to the lungs for oxygenation.

The chordae tendineae are fibrous cords that attach the cusps of the AV valves (mitral and tricuspid valves) to the ventricular walls. These cords prevent the valves from inverting or bulging into the atria during ventricular contraction. They help to maintain the proper closure of the valves and ensure the unidirectional flow of blood through the heart. The other options listed (coronary arteries, pericardium, myocardium, and precordium) are not directly involved in attaching the cusps of the AV valves to the ventricular walls.

The left ventricle is responsible for pumping oxygenated blood into the aorta, not receiving blood from the left atrium. The left atrium is the chamber that receives oxygenated blood from the lungs. The left ventricle contains oxygenated blood, as it receives blood from the left atrium. However, the oxygen from the blood within the left ventricle does not diffuse across the endocardium into the left ventricular myocardium. The myocardium is already supplied with oxygenated blood through the coronary arteries.

The pulmonic and tricuspid valves are associated with the right ventricle. The right ventricle is one of the four chambers of the heart and is responsible for pumping oxygen-depleted blood to the lungs for oxygenation. The pulmonic valve is located between the right ventricle and the pulmonary artery, while the tricuspid valve is located between the right atrium and the right ventricle. These valves ensure that blood flows in the correct direction and prevents backflow.

The coronary arteries are the blood vessels that arise at the base of the aorta just beyond the aortic valve. These arteries supply oxygenated blood to the heart muscle, known as the myocardium. Without the coronary arteries, the heart would not receive the necessary oxygen and nutrients to function properly. Therefore, the coronary arteries are crucial for maintaining a healthy heart.

A cell that spontaneously depolarizes from resting membrane potential to threshold potential is called a pacemaker cell. Pacemaker cells are specialized cells found in various tissues, including the heart, that generate electrical impulses to initiate the contraction of muscles. These cells have the ability to depolarize on their own, setting the rhythm for the entire organ. It is important to note that pacemaker cells are not limited to the heart and can also be found in other tissues throughout the body.

Stenosis of the aortic valve causes left ventricular hypertrophy because the narrowing of the valve obstructs blood flow from the left ventricle to the aorta. This obstruction increases pressure in the left ventricle, leading to the heart muscle thickening and enlarging to compensate for the increased workload.

The mitral valve and the aortic valve are associated with the left ventricle. The mitral valve is located between the left atrium and the left ventricle, allowing blood to flow from the atrium to the ventricle. The aortic valve is located between the left ventricle and the aorta, allowing blood to be pumped out of the heart and into the rest of the body. Therefore, the left ventricle is the correct answer as it is directly involved in the functioning of these valves.

The myocardium is the heart muscle, and it is found in both the ventricles and the atria. Therefore, the statement "is found in the ventricles but not the atria" is least true of the myocardium.

Blood changes from blue to red in the pulmonary capillary. This is because the pulmonary capillary is the site where oxygen is taken up by the red blood cells and carbon dioxide is released. Oxygenated blood appears red, while deoxygenated blood appears blue. Therefore, as the blood passes through the pulmonary capillary and picks up oxygen, it changes from blue to red.

An enlarged myocardium (ventricular hypertrophy) indicates that the heart must work harder than normal. Ventricular hypertrophy occurs as a result of increased workload on the heart, such as in conditions like hypertension or heart valve disorders. The heart muscle thickens in response to the increased demand, allowing the heart to pump blood effectively. This adaptation helps to compensate for the increased workload and maintain cardiac output.

S2 is the second heart sound, commonly referred to as "lubb." It occurs due to the closure of the semilunar valves (pulmonary and aortic valves) at the beginning of ventricular relaxation. This closure creates a sound that can be heard during cardiac auscultation. The other options mentioned, such as the contraction of the ventricular myocardium or the firing of the SA node, are not directly related to the generation of the S2 sound.

In a healthy heart, coronary blood flow can increase, which is necessary to meet the increased oxygen demands during physical activity. Atherosclerotic coronary blood vessels are usually maximally dilated at rest, as the narrowed arteries cannot dilate further to increase blood flow. A decrease in coronary blood flow causes pain, known as angina, as the heart muscle does not receive enough oxygen. Therefore, all of the statements mentioned in the options are true.

The correct answer is pulmonic because the pulmonic valve is located between the right ventricle and the pulmonary artery. It is responsible for preventing the backflow of blood from the pulmonary artery into the right ventricle. Since the pulmonary artery carries deoxygenated blood from the heart to the lungs, the pulmonic valve "sees" unoxygenated blood.

The pleural cavity is the space between the two layers of the pleura, which is a membrane that surrounds the lungs. It does not contain the heart. The thoracic cavity contains the heart, lungs, and other organs. The ventral cavity is a larger cavity that includes the thoracic and abdominal cavities. The mediastinum is a subdivision of the thoracic cavity and it contains the heart, among other structures. Therefore, the correct answer is pleural cavity.

The action potential in the heart consists of two phases: depolarization and repolarization. During depolarization, the electrical charge of the cardiac cells becomes more positive, leading to the contraction of the heart muscle. Repolarization, on the other hand, is the process of restoring the electrical charge of the cells back to their resting state, allowing the heart to relax and prepare for the next contraction. These two phases are crucial for the proper functioning of the heart and the coordination of its contractions.

Stenosis of the aortic valve refers to the narrowing of the valve opening, which obstructs the flow of blood from the left ventricle to the aorta. As a result, the left ventricle has to work harder to pump blood through the narrowed valve, leading to increased pressure and causing left ventricular hypertrophy. This condition is characterized by the thickening and enlargement of the left ventricular muscle. Therefore, the correct answer is aortic.

The firing of the SA node refers to the initiation of the electrical signal that starts the cardiac cycle, while "lubb" (the first heart sound) is caused by the closure of the AV valves. These two events are not directly related to each other, making "caused by the firing of the SA node" the least related option.

The precordium refers to the area of the chest wall that overlies the heart and great vessels. It is the region where the heart can be palpated and auscultated. This area includes the sternum, ribs, and intercostal spaces. The term "precordium" is often used to describe the location where cardiac examination is performed and where heart sounds are heard.