Question

The defect shown in image relates to which of the following?

• A. Left 4th aortic arch
• B. Right 4th aortic arch
• C. Left 6th aortic arch
• D. Right 6th aortic arch

Hint:

Left 4th aortic arch forms part of the arch of aorta, while right 4th aortic arch contributes to the right subclavian artery.

Answer 1

The Correct Option is B

Concept: Aortic arch derivatives are important in embryology. The 4th aortic arch contributes to major arterial structures on both sides.

Step 1: Recall derivatives of the 4th arch.
The left 4th aortic arch forms part of the arch of aorta. The right 4th aortic arch forms part of the right subclavian artery.

Step 2: Relate the image defect.
The defect shown in the heart and great vessel image corresponds to abnormal development involving the right-sided arch derivative.

Step 3: Choose the correct embryological structure.
Thus, the defect relates to: \[ \text{Right 4th aortic arch} \]