Block 3 Heart Anatomy And Valvular Pathology

1. Over distension of the vaIves of the atrioventricular orifices of the heart is prevented by the papillary muscles and the:

Crista termina/is

Ligamentum teres

Chordae tendineae

Trabeculae carneae

Ligamentum venosum

The correct answer is chordae tendineae. Chordae tendineae are fibrous cords that connect the papillary muscles to the atrioventricular valves (AV valves) in the heart. When the ventricles contract, the papillary muscles also contract, pulling on the chordae tendineae, which in turn prevent the AV valves from over distending or prolapsing into the atria. This helps to maintain proper blood flow through the heart and prevents backflow of blood into the atria. The other options listed are not directly involved in preventing over distension of the AV valves.

Explanation

The correct answer is chordae tendineae. Chordae tendineae are fibrous cords that connect the papillary muscles to the atrioventricular valves (AV valves) in the heart. When the ventricles contract, the papillary muscles also contract, pulling on the chordae tendineae, which in turn prevent the AV valves from over distending or prolapsing into the atria. This helps to maintain proper blood flow through the heart and prevents backflow of blood into the atria. The other options listed are not directly involved in preventing over distension of the AV valves.

2. Which group of structures empties directly into the right atrium?

Superior vena cava, coronary sinus and hemiazygos vein

Coronary sinus and pulmonary vein

Pulmonary and bronchial veins the following

Superior and inferior vena cava and coronary sinus

Coronary sinus and azygos vein

The superior and inferior vena cava and coronary sinus are the three structures that empty directly into the right atrium. The superior vena cava brings deoxygenated blood from the upper body, the inferior vena cava brings deoxygenated blood from the lower body, and the coronary sinus brings deoxygenated blood from the heart muscle itself. Together, these structures help to return deoxygenated blood to the right side of the heart for oxygenation.

Explanation

The superior and inferior vena cava and coronary sinus are the three structures that empty directly into the right atrium. The superior vena cava brings deoxygenated blood from the upper body, the inferior vena cava brings deoxygenated blood from the lower body, and the coronary sinus brings deoxygenated blood from the heart muscle itself. Together, these structures help to return deoxygenated blood to the right side of the heart for oxygenation.

3. Which vein accompanies the posterior interventricular artery?

Great cardiac

Marginal

Middle cardiac

Small cardiac

Coronary sinus

The middle cardiac vein accompanies the posterior interventricular artery.

Explanation

The middle cardiac vein accompanies the posterior interventricular artery.

4. A blood clot (embolus) found in the left pulmonary artery probably came from which of the following?

Pulmonary veins

Left atrium

Right ventricle

Left brachiocephalic vein

Left ventricle

A blood clot found in the left pulmonary artery most likely came from the right ventricle. This is because blood flows from the right ventricle to the pulmonary artery, which then carries the blood to the lungs for oxygenation. If a blood clot forms in the right ventricle, it can travel through the pulmonary artery and become lodged in the left pulmonary artery.

Explanation

A blood clot found in the left pulmonary artery most likely came from the right ventricle. This is because blood flows from the right ventricle to the pulmonary artery, which then carries the blood to the lungs for oxygenation. If a blood clot forms in the right ventricle, it can travel through the pulmonary artery and become lodged in the left pulmonary artery.

5. Which of the following accompanies the anterior interventricular artery?

Middle cardiac vein

Coronary sinus

Small cardiac vein

Great cardiac vein

Anterior cardiac vein

The great cardiac vein accompanies the anterior interventricular artery. The great cardiac vein runs alongside the anterior interventricular artery and collects blood from the heart muscle supplied by this artery. It then drains into the coronary sinus, which is the main vein that collects blood from the heart muscle and returns it to the right atrium of the heart.

Explanation

The great cardiac vein accompanies the anterior interventricular artery. The great cardiac vein runs alongside the anterior interventricular artery and collects blood from the heart muscle supplied by this artery. It then drains into the coronary sinus, which is the main vein that collects blood from the heart muscle and returns it to the right atrium of the heart.

6. A 62-year-old woman presents to your office with new onset atrial fibrillation. She thinks she may have had "rheumatic fever" as a child but isn't sure. She has no other medical conditions and is not on any medications. On examination you note a diastolic murmur at the left side of the chest in the 5th intercostal space. What is the most likely cause of her atriaI fibriIIatron?

Aortic valve stenosis with left ventricuIar hypertrophy

PuImonic valve stenosis with pulmonary hypertension

Tricuspid vaIve stenosis with pulmonary hypertension

Mitral valve stenosis with left atrial dilatation

rheumatic fever THINK mitral valve

Explanation

rheumatic fever THINK mitral valve

7. The heart is located in which anatomical subdivision of the mediastinum?

Posterior

Lateral

Superior

The heart is located in the middle anatomical subdivision of the mediastinum. The mediastinum is the central compartment of the chest, located between the lungs. It is divided into anterior, middle, and posterior subdivisions. The heart is positioned in the middle subdivision of the mediastinum, surrounded by other structures such as the great vessels, thymus gland, and lymph nodes.

Explanation

The heart is located in the middle anatomical subdivision of the mediastinum. The mediastinum is the central compartment of the chest, located between the lungs. It is divided into anterior, middle, and posterior subdivisions. The heart is positioned in the middle subdivision of the mediastinum, surrounded by other structures such as the great vessels, thymus gland, and lymph nodes.

8. CARDIAC ANATOMY During a heart procedure, the surgeon accidently damages the vein that is accompanied by the posterior interventricular artery. Which of the following veins is most likely to be damaged?

Great cardiac vein

Middle cardiac vein

Small cardiac vein

Anterior cardiac vein

Oblique vein of the left atrium

The middle cardiac vein is most likely to be damaged in this scenario because it runs alongside the posterior interventricular artery. Since the surgeon accidentally damaged the vein accompanied by this artery, it suggests that the middle cardiac vein was affected. The other veins listed do not have a direct association with the posterior interventricular artery, making them less likely to be damaged in this situation.

Explanation

The middle cardiac vein is most likely to be damaged in this scenario because it runs alongside the posterior interventricular artery. Since the surgeon accidentally damaged the vein accompanied by this artery, it suggests that the middle cardiac vein was affected. The other veins listed do not have a direct association with the posterior interventricular artery, making them less likely to be damaged in this situation.

9. The apex of the heart is formed by the:

Left atrium

Left ventricle

Right atrium

Right ventricle

Both left and right ventricles

The apex of the heart is the pointed bottom part of the heart. It is formed by the left ventricle, which is the chamber responsible for pumping oxygenated blood to the rest of the body. The left ventricle is thicker and more muscular than the right ventricle, as it needs to generate enough force to propel blood throughout the entire body. Therefore, the left ventricle is responsible for forming the apex of the heart.

Explanation

The apex of the heart is the pointed bottom part of the heart. It is formed by the left ventricle, which is the chamber responsible for pumping oxygenated blood to the rest of the body. The left ventricle is thicker and more muscular than the right ventricle, as it needs to generate enough force to propel blood throughout the entire body. Therefore, the left ventricle is responsible for forming the apex of the heart.

10. A 70 year-old woman is brought to the emergency room by her daughter, who noticed that her mother is not as energetic as she previously was. Tests revealed the following patient data : Left ventricular pressure 110/0 mmHg Right ventricular pressure 95/5 mmHg Pulmonary artery pressure 20/0 mmHg Aortic pressure 110/60 mmHg Which of the following diagnoses is most consistent with the above information?

Systemic hypertension

Pulmonic valve stenosis

Aortic valve regurgitation

Left heart failure

Aortic valve stenosis

Pulmonic valve regurgitation

The patient's left ventricular pressure is normal, indicating that left heart failure is unlikely. The pulmonary artery pressure is also normal, ruling out pulmonary hypertension. The aortic pressure is within the normal range, making aortic valve regurgitation and aortic valve stenosis less likely. The right ventricular pressure is elevated, suggesting a problem with the right side of the heart. The most consistent diagnosis with these findings is pulmonic valve stenosis, which would cause increased pressure in the right ventricle.

Explanation

The patient's left ventricular pressure is normal, indicating that left heart failure is unlikely. The pulmonary artery pressure is also normal, ruling out pulmonary hypertension. The aortic pressure is within the normal range, making aortic valve regurgitation and aortic valve stenosis less likely. The right ventricular pressure is elevated, suggesting a problem with the right side of the heart. The most consistent diagnosis with these findings is pulmonic valve stenosis, which would cause increased pressure in the right ventricle.

11. In preparation for thoracic surgery, a median sternal splitting procedure was carried out. But an improper depth setting on the saw blade resulted in a slight nick on the underlying sternocostal surface of the heart. Which heart chamber would most likely have been opened had the blade completely penetrated this wall?

Left atrium

Left ventricle

Right atrium

Right ventricle

If the blade had completely penetrated the sternocostal wall, the heart chamber that would most likely have been opened is the right ventricle. The right ventricle is located on the right side of the heart and is the chamber responsible for pumping oxygen-depleted blood to the lungs. The sternocostal surface of the heart is the anterior surface of the heart that faces the sternum and ribs, and the right ventricle is located in close proximity to this surface. Therefore, if the blade had penetrated this wall, it would most likely have entered the right ventricle.

Explanation

If the blade had completely penetrated the sternocostal wall, the heart chamber that would most likely have been opened is the right ventricle. The right ventricle is located on the right side of the heart and is the chamber responsible for pumping oxygen-depleted blood to the lungs. The sternocostal surface of the heart is the anterior surface of the heart that faces the sternum and ribs, and the right ventricle is located in close proximity to this surface. Therefore, if the blade had penetrated this wall, it would most likely have entered the right ventricle.

12. Valvular Disorders and Murmurs A 35-year-old woman sees her doctor for a routine physical, and a heart murmur is heard between S1 and S2. Further tests reveal an increase in right atrial pressure and right ventricular eccentric hypertrophy, and normal left heart values. Which of the following valve disorders is most likely present in this patient?

Aortic vaIve stenosis

Mitral valve regurgitation

Pulmonic valve stenosis

Tricuspid valve regurgitation

Tricuspid valve stenosis

murmur after S1 is either bi or tri cuspid, right side problems indicate tri

Explanation

murmur after S1 is either bi or tri cuspid, right side problems indicate tri

13. The thoracic duct empties directly into the junction of the:

Superior vena cava and the azygos veins

Left jugular and brachiocephalic veins

Right jugular and brachiocephalic vein

Left internal jugular and subclavian veins

Right internal jugular and subclavian veins

The thoracic duct is the largest lymphatic vessel in the body and it drains lymph from the lower body and left side of the upper body. It empties into the junction of the left internal jugular and subclavian veins. This is the correct answer because the thoracic duct is located on the left side of the body and it drains into these specific veins. The other options are incorrect because they either involve the wrong side of the body or different veins.

Explanation

The thoracic duct is the largest lymphatic vessel in the body and it drains lymph from the lower body and left side of the upper body. It empties into the junction of the left internal jugular and subclavian veins. This is the correct answer because the thoracic duct is located on the left side of the body and it drains into these specific veins. The other options are incorrect because they either involve the wrong side of the body or different veins.

14. Which of the following structures maintains constant tension on the cusps of the atrioventricuIar valves?

Pectinate muscle

Anulus fibrosis (rings)

Moderator band

Crista terminalis

Chordae tendineae

The chordae tendineae are fibrous cords that connect the cusps of the atrioventricular valves (mitral and tricuspid valves) to the papillary muscles in the ventricles. These cords help to anchor the valves in place and prevent them from prolapsing into the atria during ventricular contraction. By maintaining constant tension on the cusps, the chordae tendineae ensure proper closure of the valves and prevent backflow of blood into the atria. Therefore, the chordae tendineae are responsible for maintaining constant tension on the cusps of the atrioventricular valves.

Explanation

The chordae tendineae are fibrous cords that connect the cusps of the atrioventricular valves (mitral and tricuspid valves) to the papillary muscles in the ventricles. These cords help to anchor the valves in place and prevent them from prolapsing into the atria during ventricular contraction. By maintaining constant tension on the cusps, the chordae tendineae ensure proper closure of the valves and prevent backflow of blood into the atria. Therefore, the chordae tendineae are responsible for maintaining constant tension on the cusps of the atrioventricular valves.

15. A 28-year-old man who had rheumatic fever as a child comes to the physician's office because of fatigue and dyspnea for the past 4 months. An early diastolic sound followed by a low-pitched rumbling decrescendo diastolic murmur is present 4 cm left of the sternal border In the fourth intercostals space. Which of the following valve defects is most likely in this patient?

Aortic regurgitation

Aortic stenosis

Mitral regurgitation

Mitral stenosis

Pulmonic regurgitation

Pulmonic stenosis

Tricuspid regurgitation

Tricuspid stenosis

rheumatic fever = mitral valve, diastolic murmur is mitral stenosis

Explanation

rheumatic fever = mitral valve, diastolic murmur is mitral stenosis

16. A patient comes to your office complaining of breathlessness and "puffiness is his legs". Upon examination, you detect an elevated jugular venous pulse, an S4 heart sound, and a systolic murmur. Based on these findings, what is his likely diagnosis?

Aortic valve stenosis

Mitral valve regurgitation

Tricuspid valve regurgitation

Tricuspid valve stenosis

Pulmonic valve stenosis

Jugular pulse = right side, leg edema from increased pressure in right atrium, breathless from decreased c/o S4 is post closure of pulmonic and aortic valves, right side indicates pulmonic

Explanation

Jugular pulse = right side, leg edema from increased pressure in right atrium, breathless from decreased c/o S4 is post closure of pulmonic and aortic valves, right side indicates pulmonic

17. In obstruction of the superior or inferior vena cava, venous blood is returned to the heart by an alternate route via the azygos vein, which becomes dilated in the process. Which of the following structures might it compress as a result?

Trachea

Root of the left lung

Phrenic nerve

Thoracic duct

Descending aorta

When there is obstruction of the superior or inferior vena cava, blood flow is redirected through the azygos vein. The azygos vein becomes dilated as a result. The thoracic duct is a structure that runs alongside the azygos vein in the posterior mediastinum. Therefore, the dilated azygos vein can compress the thoracic duct, leading to obstruction or impaired flow of lymphatic fluid through the duct.

Explanation

When there is obstruction of the superior or inferior vena cava, blood flow is redirected through the azygos vein. The azygos vein becomes dilated as a result. The thoracic duct is a structure that runs alongside the azygos vein in the posterior mediastinum. Therefore, the dilated azygos vein can compress the thoracic duct, leading to obstruction or impaired flow of lymphatic fluid through the duct.

18. If the right coronary artery is blocked by a fat globule after giving off the right marginal artery, which ofthe following structures may have oxygen deficiency?

Right atrium

SA node

AV node

Apex of the heart

Root of the pulmonary trunk

If the right coronary artery is blocked after giving off the right marginal artery, the blood supply to the AV node may be compromised. The AV node is located in the right atrium near the septum, and it is responsible for conducting electrical signals between the atria and the ventricles. If the AV node does not receive enough oxygenated blood, it may not function properly, leading to disturbances in the electrical conduction system of the heart. This can result in abnormal heart rhythms or even complete heart block.

Explanation

If the right coronary artery is blocked after giving off the right marginal artery, the blood supply to the AV node may be compromised. The AV node is located in the right atrium near the septum, and it is responsible for conducting electrical signals between the atria and the ventricles. If the AV node does not receive enough oxygenated blood, it may not function properly, leading to disturbances in the electrical conduction system of the heart. This can result in abnormal heart rhythms or even complete heart block.

19. A decrease in ventricular compliance as a result of untreated chronic systemic hypertension will lead to which of the following?

Decreased afterload

Decreased preload

Decreased inotropy (contractility)

Increased end systolic volume

Decreased chronotropy (heart rate)

stiffness leads to a decrease in the ejection fraction

Explanation

stiffness leads to a decrease in the ejection fraction

20. Which set of cardiovascular parameters below would most closely fits someone suffering from severe pulmonic valve regurgitation? RAP Pc of pulm capillaries RV hypertrophy Murmur

Inc dec . present diastolic

Inc dec not present systolic

Inc inc present diastolic

Inc inc present systolic

Dec dec not present diastolic

Dec inc not present systolic

Dec inc present diastolic

A person with severe pulmonic valve regurgitation would have an increased right atrial pressure (RAP) due to the backflow of blood into the right atrium. The pulmonary capillary pressure (Pc of pulm capillaries) would be decreased because the regurgitation causes blood to flow back into the right ventricle instead of being pushed into the pulmonary circulation. The person would also have right ventricular hypertrophy (RV hypertrophy) as a result of the increased workload on the right ventricle. A diastolic murmur would be present due to the regurgitation occurring during diastole.

Explanation

A person with severe pulmonic valve regurgitation would have an increased right atrial pressure (RAP) due to the backflow of blood into the right atrium. The pulmonary capillary pressure (Pc of pulm capillaries) would be decreased because the regurgitation causes blood to flow back into the right ventricle instead of being pushed into the pulmonary circulation. The person would also have right ventricular hypertrophy (RV hypertrophy) as a result of the increased workload on the right ventricle. A diastolic murmur would be present due to the regurgitation occurring during diastole.

21. Which of the following cardiac veins empties directly into the right atrium of the heart?

Middle cardiac

Anterior cardiac

Small cardiac

Great cardiac

None of the above

The anterior cardiac vein is the only one among the options that directly empties into the right atrium of the heart. The middle cardiac vein drains into the coronary sinus, which then empties into the right atrium. The small cardiac vein and great cardiac vein also drain into the coronary sinus, not directly into the right atrium. Therefore, the correct answer is the anterior cardiac vein.

Explanation

The anterior cardiac vein is the only one among the options that directly empties into the right atrium of the heart. The middle cardiac vein drains into the coronary sinus, which then empties into the right atrium. The small cardiac vein and great cardiac vein also drain into the coronary sinus, not directly into the right atrium. Therefore, the correct answer is the anterior cardiac vein.

22. A surgical procedure requires you to separate the left brachiocephalic vein. Which of the following structures is least likely at risk of being damaged?

Right brachiocephalic artery

Left subclavian artery

Left common carotid artery

Right pulmonary trunk

Right vagus nerve

During a surgical procedure to separate the left brachiocephalic vein, the least likely structure at risk of being damaged is the right pulmonary trunk. The right pulmonary trunk is located in the chest and carries deoxygenated blood from the right ventricle of the heart to the lungs. Since the procedure is focused on the left side, the right pulmonary trunk is not directly involved and therefore less likely to be damaged. The other structures mentioned, such as the right brachiocephalic artery, left subclavian artery, left common carotid artery, and right vagus nerve, may be at greater risk due to their proximity to the left brachiocephalic vein.

Explanation

During a surgical procedure to separate the left brachiocephalic vein, the least likely structure at risk of being damaged is the right pulmonary trunk. The right pulmonary trunk is located in the chest and carries deoxygenated blood from the right ventricle of the heart to the lungs. Since the procedure is focused on the left side, the right pulmonary trunk is not directly involved and therefore less likely to be damaged. The other structures mentioned, such as the right brachiocephalic artery, left subclavian artery, left common carotid artery, and right vagus nerve, may be at greater risk due to their proximity to the left brachiocephalic vein.