Neural crest cells that migrate from the post-otic rhombomeres (r6–r8) contribute to which of the following structures?

• A Meckel's cartilage and the mandible
• B Stapes and stylohyoid ligament
• C Malleus and incus
• D Cardiac outflow tract septation and the aorticopulmonary septum ✓

Explanation

Cardiac neural crest cells derive from the post-otic rhombomeres (r6–r8) and migrate into the pharyngeal arches 3, 4, and 6 and into the cardiac outflow tract. They are essential for formation of the aorticopulmonary septum dividing the truncus arteriosus into the aorta and pulmonary artery, and for the smooth muscle of the great vessel walls. Disruption of cardiac neural crest causes persistent truncus arteriosus and interrupted aortic arch. Meckel's cartilage, malleus, and incus arise from first-arch neural crest; stapes and stylohyoid ligament arise from second-arch neural crest.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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