Cardiovascular and Respiratory Systems is part of the Embryology section of Anatomy. Practise 50 exam-style MCQs for NEET PG, FMGE, INI-CET and NEET SS, each with the correct answer and a detailed explanation.
Cardiovascular and Respiratory Systems MCQs follow fetal shunts such as the foramen ovale and ductus arteriosus, septation of the heart, the sixth arch arteries, and how faulty spiralling of the aorticopulmonary septum produces transposition — high-yield NEET PG revision.
Sample Cardiovascular and Respiratory Systems MCQs with answers
Sample MCQ #1
The blood vessels that carry relatively "pure" arterial blood during fetal development are:
ASuperior vena cava
BInferior vena cava below liver
CPulmonary artery
DAscending aorta
Show Answer & Explanation ▾
✓ Correct Answer: D. Ascending aorta
The posthepatic inferior vena cava carries oxygenated blood from the ductus venosus. Upon reaching the heart, most of this blood passes through the foramen ovale to the left heart and the ascending aorta, leaving poorly oxygenated blood entering from superior vena cava to reach right ventricle and pulmonary trunk Reference - Textbook of Langman's, 12th Edition, Cardiovascular System Embryology Page number - 185
Sample MCQ #2
Fossa ovalis closes because of fusion of ?
ASeptum primum + Endocardial cushion
BSeptum secundum + Endocardial cushion
CSeptum primum + Septum secundum
DNone
Show Answer & Explanation ▾
✓ Correct Answer: C. Septum primum + Septum secundum
Ans. is 'c' i.e., Septum primum + Septum secundum [Ref Essentials of human embryology — 213-215] After birth, the foramen ovale closes by fusion of septum primum with septum secundum.
Sample MCQ #3
The embryonic origin of the ligamentum arteriosum is from the:
ASecond arch artery
BThird arch artery
CFourth arch artery
DSixth arch artery
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✓ Correct Answer: D. Sixth arch artery
The sixth arch is the pulmonary arch, from which pulmonary arteries are derived. On the left side, this arch maintains its connection with the dorsal aorta. In the fetus, this connection is patent and is called the ductus arteriosus. Postnatally, it closes and persists as the ligamentum arteriosum. Reference - Textbook of Langman's, 12th Edition, Cardiovascular System Embryology Page number - 162
Sample MCQ #4
A newborn developed cyanosis soon after birth. Chest X-ray showed the characteristic egg-on-a-string appearance. Which of the following mechanisms during embryonic development will most likely lead to the given condition?
ANon-fusion of aortico-pulmonary septum with truncus arteriosus
BAnterior displacement of aortico-pulmonary septum
CFailure of cono-truncal ridge to fuse and descend
DAortico-pulmonary septum not following its spiral course
Show Answer & Explanation ▾
✓ Correct Answer: D. Aortico-pulmonary septum not following its spiral course
The egg-on-a-string appearance on chest X-ray is characteristically seen in the transposition of great arteries (TGA). It is considered to arise due to abnormal spiraling of the aortopulmonary septum (conotruncal septum). Reference - Textbook of Langman's, 12th Edition, Cardiovascular System Embryology Page number - 171
Sample MCQ #5
The limbus fossa ovalis is the remnant of
ASeptum primum
BSeptum secundum
CBoth A and B
DNone of the above
Show Answer & Explanation ▾
✓ Correct Answer: B. Septum secundum
The limbus fossa ovalis (also known as annulus ovalis represents the remnant of the lower free edge of the septum secundum. Fossa ovalis is an oval-shaped depression in the septal wall of the right atrium just above the opening of inferior vena cava. It marks the location of embryonic foramen ovale. The floor of fossa ovalis is the remnant of septum primum. The limbus of fossa ovalis is the prominent upper margin of the fossa ovalis and a remnant of the septum secundum. Reference - Textbook of Langman's, 12th Edition, Cardiovascular System Embryology Page number - 185
Sample MCQ #6
In the development of the heart, which is NOT correct:
AThe heart primordium is initially located in mesenchyme in front of the prochordal plate
BCommon cardinal veins empty into the sinus venosus
CThe interatrial septum is formed from endocardial cushions, septum primum and septum secundum
DOnly cardiac muscle contributes to the interventricular septum
Show Answer & Explanation ▾
✓ Correct Answer: D. Only cardiac muscle contributes to the interventricular septum
Heart development initially occurs in front of the prochordal plate. The common cardinal, vitelline and umbilical veins enter the sinus venosus. The interatrial septum is formed by endocardial cushions, septum primum & septum secundum. The interventricular septum has muscular and membranous parts. Reference - Textbook of Langman's, 12th Edition, Cardiovascular System Embryology Page number - 185
Sample MCQ #7
Concerning the truncus ridges, which statement is NOT correct:
AThey may grow abnormally and contribute to formation of transposition of the great vessels
BThey normally spiral around each other as they grow
CThey form the aorticopulmonary septum
DThey contribute to the interatrial septum
Show Answer & Explanation ▾
✓ Correct Answer: D. They contribute to the interatrial septum
The truncal ridges or swellings are the progenitors of the aorticopulmonary septum within the truncus arteriosus. During development, they spiral, properly orienting the aorta and pulmonary trunks. If they fail to spiral, transposition of the great vessels can occur. They do not involve the interatrial septum. Reference - Textbook of Langman's, 12th Edition, Cardiovascular System Embryology Page number - 185
Sample MCQ #8
Transposition of the great vessels is most directly related to abnormal development of which of the following?
ATruncus arteriosus
BTruncal ridges
CBulbus cordis
DSeptum primum
Show Answer & Explanation ▾
✓ Correct Answer: B. Truncal ridges
The spiral aorticopulmonary septum forms within the truncus arteriosus as the result of the growth of the truncal swellings or ridges. Reference - Textbook of Langman's, 12th Edition, Cardiovascular System Embryology Page number - 170
What you can practise in Cardiovascular and Respiratory Systems
50 Cardiovascular and Respiratory Systems MCQs on Cardiovascular, Respiratory Systems, Embryology — each with detailed explanations
Previous-year question practice across NEET PG, FMGE, INI-CET and NEET SS
Progress and performance tracking to measure retention
What do Cardiovascular and Respiratory Systems MCQs cover?
Cardiovascular and Respiratory Systems MCQs follow fetal shunts such as the foramen ovale and ductus arteriosus, septation of the heart, the sixth arch arteries, and how faulty spiralling of the aorticopulmonary septum produces transposition — high-yield NEET PG revision.
How many Cardiovascular and Respiratory Systems questions are there, and which exams do they cover?
MedLadder includes 50 curated MCQs for Cardiovascular and Respiratory Systems under Anatomy (Embryology), covering NEET PG, FMGE, INI-CET and NEET SS preparation.
