Question

question
the opening in the interatrial septum of the heart, between the 5th week of embryonic development and birth, is called the:
answer
fossa ovalis.
trabeculae carneae.
conus arteriosus.
foramen ovale.

Explanation:

• Fossa ovalis: It is a depression in the right atrium of the heart. It is the remnant of a thin fibrous sheet that covered the foramen ovale during fetal development, not the opening itself.
• Trabeculae carneae: These are muscular ridges in the ventricles of the heart. They have no relation to the inter - atrial septum opening.
• Conus arteriosus: It is a conical pouch from the upper and left - posterior part of the right ventricle in the heart. It is not an opening in the inter - atrial septum.
• Foramen ovale: During fetal development (from about the 5th week of embryonic development until birth), the foramen ovale is an opening in the inter - atrial septum that allows blood to bypass the non - functional fetal lungs.

Answer:

foramen ovale.