Question:
Which best describes the embryological basis of the foramen ovale?
Which best describes the embryological basis of the foramen ovale?
Show Hint
Atrial Septation Anatomy:
$\bullet$ Valve of foramen ovale = Septum Primum (thin, on left atrial side).
$\bullet$ Limbus of foramen ovale = Free edge of Septum Secundum (thick, on right atrial side).
$\bullet$ Valve of foramen ovale = Septum Primum (thin, on left atrial side).
$\bullet$ Limbus of foramen ovale = Free edge of Septum Secundum (thick, on right atrial side).
Updated On: Sep 3, 2026
- It forms the upward growth of septum primum and downward growth of septum secundum
- It develops as a persistant space within septum primum
- It forms as a passage between the overlapping margins of the septum primum and secundum
- It results from incomplete fusion of endocardial cushions
Show Solution
Verified By Collegedunia
The Correct Option is C
Solution and Explanation
Concept:
Interatrial septation in the embryonic heart involves the sequential development and interaction of two distinct partitions: the septum primum and the septum secundum.
The foramen ovale is the physiological flap-valve orifice that allows right-to-left shunting of blood in the fetal heart.
Explanation:
• The septum primum grows downward from the atrial roof toward the endocardial cushions, leaving an initial opening (ostium primum). Before the ostium primum completely closes, apoptosis in the superior portion creates the ostium secundum.
• Subsequently, a thick, muscular septum secundum grows downward immediately to the right of the septum primum.
• The septum secundum does not form a complete wall; its free lower crescentic margin leaves an oval aperture called the foramen ovale.
• The thin, flexible upper remnant of the septum primum remains on the left atrial side and acts as the flap valve of the foramen ovale.
• Thus, the foramen ovale exists as an oblique, tunnel-like passage formed between the overlapping margins of the rigid septum secundum and the mobile flap of the septum primum.
• At birth, left atrial pressure rises above right atrial pressure, pressing the valve of the septum primum firmly against the septum secundum and functionally sealing the foramen.
Final Answer:
The foramen ovale is embryologically formed as an overlapping valvular passage between the margins of the septum primum and septum secundum.
Interatrial septation in the embryonic heart involves the sequential development and interaction of two distinct partitions: the septum primum and the septum secundum.
The foramen ovale is the physiological flap-valve orifice that allows right-to-left shunting of blood in the fetal heart.
Explanation:
• The septum primum grows downward from the atrial roof toward the endocardial cushions, leaving an initial opening (ostium primum). Before the ostium primum completely closes, apoptosis in the superior portion creates the ostium secundum.
• Subsequently, a thick, muscular septum secundum grows downward immediately to the right of the septum primum.
• The septum secundum does not form a complete wall; its free lower crescentic margin leaves an oval aperture called the foramen ovale.
• The thin, flexible upper remnant of the septum primum remains on the left atrial side and acts as the flap valve of the foramen ovale.
• Thus, the foramen ovale exists as an oblique, tunnel-like passage formed between the overlapping margins of the rigid septum secundum and the mobile flap of the septum primum.
• At birth, left atrial pressure rises above right atrial pressure, pressing the valve of the septum primum firmly against the septum secundum and functionally sealing the foramen.
Final Answer:
The foramen ovale is embryologically formed as an overlapping valvular passage between the margins of the septum primum and septum secundum.
Was this answer helpful?
0
0
Top NEET SS Paediatrics Questions
- A 2-year-old child presents with persistent fever for 4 days. Examination shows conjunctival injection and periungual desquamation, but criteria for complete Kawasaki disease are not met. You plan to evaluate for incomplete Kawasaki disease as per AHA guidelines. Which of the following investigations is NOT routinely recommended in this evaluation?
- A 27-year-old pregnant woman with systemic lupus erythematosus (SLE) is concerned about the risk of congenital heart block in her fetus due to anti-Ro/SSA antibodies. Which of the following medications is not recommended antenatally to prevent cardiac manifestations of neonatal lupus?
- A 2-week-old infant presents with a photosensitive annular erythematous rash on the face. ECG reveals complete heart block. Which is the most likely diagnosis?
- A 10-year-old child presents with arthritis involving the wrist and first MCP joint. Examination shows nail pitting. Which of the following is the most likely diagnosis?
- A 14-year-old girl with SLE presents with edema and nephrotic-range proteinuria. Renal biopsy shows diffuse thickening of the glomerular basement membrane without proliferative lesions. This corresponds to which class of lupus nephritis?
View More Questions
Top NEET SS Cardiovascular Development Questions
- Which is the correct statement regarding fetal circulation?
- During embryonic development of the heart, looping occurs to align cardiac chambers. Which of the following is true?
- A newborn presents with stridor and severe respiratory distress. Imaging reveals compression of trachea and right main bronchus by vascular structures. Which anomaly is most likely?
- A newborn presents with stridor and respiratory distress and dysphagia. Imaging shows compression of the trachea, esophagus and right main bronchus. Which vascular anomaly is most likely responsible?
Top NEET SS Questions
- A liver transplant patient presents with diarrhoea, colitis, a total leukocyte count of 1800, and a positive blood CMV PCR. What is the next step in management?
- A 32-year-old male recovering from dengue fever initially showed clinical improvement but now presents with recurrence of high-grade fever, fatigue, and pancytopenia on day 10 of illness. He is hemodynamically stable with no bleeding manifestations. Which of the following investigations should be performed first to evaluate the cause of relapse and cytopenia?
- A 48-year-old man with chronic hepatitis C infection is being evaluated for risk factors associated with progression of liver disease. He has a 20-year history of infection, drinks alcohol occasionally, and has a high serum HCV RNA viral load. Which of the following factors is not associated with an increased risk of progression of liver disease in chronic HCV infection?
- A 28-year-old veterinary worker who previously received a full 3-dose pre-exposure rabies vaccination series is bitten by a stray dog while handling an animal in the clinic. The wound is cleaned immediately. What is the most appropriate post-exposure management?
- A 42-year-old patient undergoing chemotherapy for acute myeloid leukemia develops neutropenia (ANC $<$ 500) and is treated with broad-spectrum antibiotics. After initial recovery of neutrophil counts (ANC = 1500), he again develops high-grade fever and right upper quadrant abdominal pain. Imaging shows multiple small hypodense lesions in the liver and spleen. What is the most likely diagnosis?
View More Questions