Development of Arterial Aortic Arches

Development of Arterial Aortic Arches

• Arterial aortic arches form during embryonic development.
• Two primitive aortas form, ventral and dorsal.
• The ventral aortas fuse to form the aortic sac.
• The lower parts of the dorsal aortas fuse, forming a single dorsal aorta.
• Six arterial aortic arches develop, leading to a single dorsal aorta.
• The fifth aortic arch degenerates early in fetal development.

Fate of Arterial Aortic Arches

• The first aortic arch gives rise to the maxillary artery.

• The second aortic arch gives rise to the stapedial artery.

• The third aortic arch forms:

  • Common carotid artery
  • Proximal portion of the internal carotid artery
  • External carotid artery

• The fourth aortic arch forms:

  • Right subclavian artery on the right side
  • The main part of the arch of the aorta on the left side.

• The sixth aortic arch forms: - Ventral part - right pulmonary artery - Dorsal part - ductus arteriosus

• The aortic sac:

  • Its cranial portion degenerates
  • The caudal portion divides into two parts:
    • The left horn forms the arch of the aorta
    • The right horn forms the innominate artery

• Seventh intersegmental a:

  • The right forms part of the right subclavian artery
  • The left forms the left subclavian artery

• The arch of the aorta is formed from: the left horn of the aortic sac, the left fourth arch, and the dorsal aorta distal to the fourth arch.

• Recurrent laryngeal nerve:

  • Left hooks around the ductus arteriosus
  • Right hooks around the distal portion of the fourth arch.

Anomalies of Arterial Aortic Arches

• Double aortic arch: Persistent right dorsal aorta distal to the fourth arch.
• Right-sided aortic arch: Reversal of normal development between the two sides.
• Retropharyngeal subclavian: Abnormal origin of right subclavian artery.
• Patent ductus arteriosus: Failure of the ductus arteriosus to close.
• Transposition of great vessels: Reversed pattern of spiral aortico-pulmonary septum.
• Coarctation of the aorta: Narrowing of the aortic arch after the arch gives off the left subclavian artery.

Questions

• Question: Patent ductus arteriosus is abnormal communication between which of the following?

  • Answer: Ascending aorta and pulmonary trunk.

• Question: Which aortic arch gives rise to the ductus arteriosus?

  • Answer: Sixth aortic arch.