Block 3 The Heart Practice MCQ's The Cardiovascular System (I): The Heart
This quiz titled 'The Heart Practice MCQs' focuses on the developmental aspects of the heart within the cardiovascular system. It assesses knowledge on structural origins from the mesoderm, fetal heart chamber contributions, and common cardiac malformations, crucial for medical students and professionals.
- 1.
Which mesodermal layer gives rise to the endocardial heart tubes?
- A.
Paraxial mesoderm
- B.
Somatic mesoderm
- C.
Intermediate mesoderm
- D.
Splanchnic mesoderm
- E.
Somitic mesoderm
Correct Answer
D. Splanchnic mesodermExplanation
The splanchnic mesoderm gives rise to the endocardial heart tubes. The endocardial heart tubes are the precursors to the heart and are formed during embryonic development. The splanchnic mesoderm is one of the three layers of the mesoderm, and it is responsible for forming the cardiovascular system, including the heart. The paraxial mesoderm gives rise to the somites, which eventually form the skeletal muscles, while the somatic mesoderm forms the dermis of the skin and the musculoskeletal system. The intermediate mesoderm gives rise to the urogenital system.Rate this question:
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- 2.
Which heart chamber does the right horn of the sinus venosus contribute to during development of the fetal heart?
- A.
Left atrium
- B.
Left ventricle
- C.
Right atrium
- D.
Right ventricle
- E.
Common ventricle
Correct Answer
C. Right atriumExplanation
During the development of the fetal heart, the right horn of the sinus venosus contributes to the formation of the right atrium.Rate this question:
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- 3.
Which of the following statements concerning the aorticopulmonary septum is INCORRECT?
- A.
The aorticopulmonary septum partitions the outflow channel of the ventricles into the aorta and the pulmonary trunk
- B.
The aorticopulmonary septum is largely derived from neural crest cells
- C.
The aorticopulmonary septum contributes to the formation of the muscular interventricular septum
- D.
The aorticopulmonary septum contributes to the formation of the membranous interventricular septum
- E.
The aorticopulmonary septum undergoes a 180o spiral
Correct Answer
C. The aorticopulmonary septum contributes to the formation of the muscular interventricular septumExplanation
The aorticopulmonary septum does not contribute to the formation of the muscular interventricular septum. The muscular interventricular septum is formed by the growth and fusion of the muscular walls of the ventricles. The aorticopulmonary septum, on the other hand, divides the outflow channel of the ventricles into the aorta and the pulmonary trunk. It is largely derived from neural crest cells and undergoes a 180o spiral.Rate this question:
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- 4.
A newborn infant presents with cyanotic heart disease and fails to thrive. On examination of the heart, it was revealed that the aorta arose from the right ventricle and the pulmonary trunk arose from the left ventricle. What is the name given to this type of cardiac malformation?
- A.
Persistent truncus arteriosus
- B.
Transposition of the great vessels
- C.
Tetralogy of Fallot
- D.
Ventricular septal defect (VSD)
- E.
Atrial-septal defect (ASD)
Correct Answer
B. Transposition of the great vesselsExplanation
The correct answer is transposition of the great vessels. Transposition of the great vessels is a congenital heart defect where the aorta arises from the right ventricle and the pulmonary trunk arises from the left ventricle. This causes the oxygenated blood to circulate back to the lungs instead of being pumped to the body, leading to cyanosis and failure to thrive in the newborn infant.Rate this question:
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- 5.
Which part of the primitive heart tube gives rise to the pulmonary artery and the aorta?
- A.
Bulbus cordis
- B.
Primitive atrium
- C.
Primitive ventricle
- D.
Sinus venosus
- E.
Truncus arteriosus
Correct Answer
E. Truncus arteriosusExplanation
The truncus arteriosus gives rise to the pulmonary artery and the aorta. During embryonic development, the truncus arteriosus is a part of the primitive heart tube that eventually divides into two separate arteries, forming the pulmonary artery and the aorta. The pulmonary artery carries deoxygenated blood from the heart to the lungs, while the aorta carries oxygenated blood from the heart to the rest of the body.Rate this question:
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- 6.
During formation of the cardiac loop the primitive atrium will move
- A.
Ventrally, inferiorly and to the right
- B.
Posteriorly and superiorly
- C.
Ventrally and superiorly
- D.
Posteriorly and inferiorly
- E.
Ventrally, inferiorly and to the left.
Correct Answer
B. Posteriorly and superiorlyExplanation
During the formation of the cardiac loop, the primitive atrium moves in a posterior and superior direction. This means that it moves towards the back and towards the top. This movement is part of the complex process of cardiac development and helps to establish the correct positioning and orientation of the heart within the developing embryo.Rate this question:
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- 7.
The left sinus horn becomes the
- A.
Coronary sinus
- B.
Inferior vena cava
- C.
Oblique vein of the right atrium
- D.
Main inflow of the right atrium
- E.
Left sinus horn, there is no change
Correct Answer
A. Coronary sinusExplanation
The left sinus horn becomes the coronary sinus. This is the correct answer because during embryonic development, the sinus venosus, a structure that forms part of the heart, gives rise to the sinus horns. The left sinus horn specifically becomes the coronary sinus, which is a large vein that collects deoxygenated blood from the heart muscle and delivers it to the right atrium. The other options listed do not accurately describe the fate of the left sinus horn during development.Rate this question:
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- 8.
The sinus venarum is
- A.
Formed from the right auricle
- B.
The trabeculated part of the right atrium.
- C.
Formed from tissue of the right sinus horn
- D.
Formed from the pulmonary veins.
- E.
A ridge of tissue between the original atrial wall tissue and the smooth part of the atrium
Correct Answer
C. Formed from tissue of the right sinus hornExplanation
The sinus venarum is formed from tissue of the right sinus horn. This is because the sinus venarum is a smooth-walled portion of the right atrium, which is derived from the right sinus horn during embryonic development. The right sinus horn is one of the three sinus horns that contribute to the formation of the atria in the developing heart. Therefore, the correct answer is that the sinus venarum is formed from tissue of the right sinus horn.Rate this question:
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- 9.
Which of the following statements concerning the partitioning of the atria is CORRECT?
- A.
The septum primum is thick and muscular
- B.
The septum secundum is a transient structure which degenerates by the end of the fourth week
- C.
The ostium secundum forms by apoptosis in the central part of the septum secundum
- D.
The septum primum forms the valve of the oval foramen
- E.
The ostium primum is a common atrial-septal defect
Correct Answer
D. The septum primum forms the valve of the oval foramenExplanation
The septum primum forms the valve of the oval foramen, which is a correct statement. The septum primum is a thin, membranous structure that grows from the roof of the atrium towards the endocardial cushions. It eventually fuses with the endocardial cushions to form the atrial septum. During development, the septum primum has an opening called the ostium primum, which allows blood to flow from the right to the left atrium. As the septum secundum forms, it grows to overlap the ostium primum, creating a valve-like structure called the valve of the oval foramen. This valve allows blood to flow from the right to the left atrium during fetal development.Rate this question:
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- 10.
True or false? The muscular portion of the interventricular septum develops from growth of the myocardium.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
The muscular portion of the interventricular septum develops from the growth of the myocardium. This means that the muscle tissue in the septum is formed as the myocardium, which is the muscular layer of the heart, grows and develops. This process is essential for the proper functioning and structure of the heart, as the interventricular septum separates the left and right ventricles and helps to maintain the circulation of blood. Therefore, the statement is true.Rate this question:
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- 11.
Which of the following statements concerning the aorticopulmonary septum is INCORRECT?
- A.
The aorticopulmonary septum undergoes a 180-degree spiral
- B.
The aorticopulmonary septum is formed by fusion of conal and truncal septa
- C.
The aorticopulmonary septum partitions the aorta and the pulmonary trunk
- D.
The aorticopulmonary septum develops from splanchnic mesoderm
- E.
The aorticopulmonary septum contributes to the interventricular septum
Correct Answer
D. The aorticopulmonary septum develops from splanchnic mesodermExplanation
formed from neural crest, specifically the cardiac neural crestRate this question:
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- 12.
Failure of the aorticopulmonary septum to undergo the 180-degree spiral will result in
- A.
Tetralogy of Fallot
- B.
Transposition of the great vessels
- C.
Persistent truncus arteriosus
- D.
An atrial-septal defect
- E.
Pulmonary stenosis
Correct Answer
B. Transposition of the great vesselsExplanation
The failure of the aorticopulmonary septum to undergo the 180-degree spiral during fetal development leads to the abnormal positioning of the aorta and pulmonary artery. In transposition of the great vessels, the aorta arises from the right ventricle instead of the left ventricle, while the pulmonary artery arises from the left ventricle instead of the right ventricle. This results in a complete reversal of the normal blood flow pattern and leads to severe circulatory problems after birth.Rate this question:
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- 13.
Which of the following statements concerning the development of the atrioventricular valves is CORRECT?
- A.
The atrioventricular valves develop from mesenchyme derived from neural crest cells
- B.
The papillary muscles attached to the atrioventricular valves are formed from mounds of tissue called endoventricular cushions
- C.
Molding of the atrioventricular valves is caused by the normal turbulent flow of blood through the ventricles
- D.
The atrioventricular valve leaflets are derived from atrial wall tissue which invaginates into the atrioventricular canals
- E.
The atrioventricular valves form before the ventricles to provide a skeleton framework for each developing ventricle
Correct Answer
C. Molding of the atrioventricular valves is caused by the normal turbulent flow of blood through the ventricles -
- 14.
If you were a membranous interventricular septum, which of the following tissues would you NOT need?
- A.
Right sinus horn
- B.
Endocardial cushion
- C.
Neural crest cells
- D.
Muscular interventricular septum
- E.
Bulbar ridge
Correct Answer
A. Right sinus hornExplanation
sinous horn associated with the ATRIUM not ventricleRate this question:
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- 15.
When does the heart start to beat?
- A.
At the end of the third week
- B.
During the tenth week once the heart is fully formed
- C.
At the end of the fourth week after looping
- D.
In the fetal period when the primitive organs mature
- E.
Immediately after birth when the baby takes the first breath
Correct Answer
A. At the end of the third weekExplanation
During the third week of development, the heart starts to beat. This is a crucial stage in embryonic development when the heart begins to form and starts contracting. It is an important milestone as it marks the beginning of the circulatory system and the functioning of the heart.Rate this question:
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- 16.
The primitive heart tube develops bulges and constrictions along its anteroposterior axis. Which part of the heart tube delivers oxygenated blood to supply the embryo?
- A.
Truncus arteriosus
- B.
Sinus venosus
- C.
Primitive ventricle
- D.
Conus cordis
- E.
Primitive atrium
Correct Answer
A. Truncus arteriosusExplanation
Truncus Arteriosous becomes the AORTARate this question:
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Aug 29, 2023Quiz Edited by
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Nov 11, 2011Quiz Created by
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