Development of aorta and pulmonary trunk

To MBBS 1st yearBy Dr. Laxman Khanal

Assistant ProfessorDepartment of anatomy

BPKIHS09-05-2016

Objectives 1. Should be able to list the developmental sources of arterial system.

2. Should be able to understand the origin of pharyngeal arch system.

3. Should be able to list the derivatives of pharyngeal arch arteries.

4. Should be able to explain important developmental anomalies.

Aorta• Ascending aorta

• Arch of aortao Rt brachiocephalic trunko Lt common carotid arteryo Lt subclavian artery• Descending aortao Oesophageal & Bronchial o Post intercostal & subcostalo Mediastinal • Pulmonary trunko Rt & Lt pulmonary artery

Rt/Lt coronary arteries

Rt ventricleLt ventricle

Ascending aortaPulmonary trunk

Development of arterial systemEntire arterial system develops from either of two sources.1. Pharyngeal arch arteries2. Primitive aortas

ORAL PLATE

Source of arterial system 1.Ventral aortas ( fuses and form aortic sac)2.Aortic arches (five pairs of arch arteries)3.Dorsal aortas (fused and unfused portion)

Maxillary artery

Stapedial arteryHyoid artery

Carotid duct

7th Cervical Intersegmental artery

Dorsal and ventral parts of aortic sac

Ductus arteriosus

parts obliterated• B/L carotid duct• Right dorsal aorta beyond 4th arch• Right distal part of 6th arch

Ventral part of aortic sacLeft horn of aortic sacLeft 4th arch arteryLeft part of dorsal aortaFused portion of dorsal aorta

Aorta development• Truncus arteriosus• Aortic sac• Left horn of aortic sac• Left fourth arch artery• Unfused left dorsal aorta• Fused dorsal aorta

Relationship of recurrent laryngeal nerve

Source Derivatives Aortic sac Proximal part of arch of aortaHorns of aortic sac Right- right brachiocephalic trunk

Left- part of arch of aorta3rd arch artery Common carotid artery

Internal carotid artery (+upper dorsal aorta)External carotid artery ( from arterial bud)

4th arch artery Rt- Rt subclavian (+7th cervical intersegmental artery)Lt- arch of aorta

6th arch Rt- Rt. pulmonary arteryLt- Lt pulmonary artery - Ductus arteriosus

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Patent ductus arteriosus

Pulmonary congestion

Causes• Hypoxia• Prostaglandin E

Preductal• Less common• DA remain patentPostductal• More common• DA obliterated• Rib notching• Differential pressure

Coarctation of aorta

Rib notching (radiographic sign)Due to enlargement of anastomotic channel between ant and posterior intercostal arteries.

Abnormal origin of Rt subclavian artery

Rt 4th arch obliteratesRt dorsal aorta persists

Double aortic archRt dorsal aorta between 7th interssegmetal artery and fused dorsal aorta persists.

Vascular ring• Dysphagia • Difficulty in breathing

Assessment

Q. All are the direct branches of aorta except.a. Right brachiocephalic trunk b. left brachiocephalic trunkc. Left common carotid artery d. left subclavian artery

Q. Which of the following arterial malformations is very common in premature infants?(A) Patent ductus arteriosus (B) Coarctation of the aorta(C) Abnormal right subclavian artery (D) Double aortic arch

Q. Ascending aorta and pulmonary trunk are derivatives of.a. Ductus arteriosus b. Dorsal aortac. Aortic sac d. Truncus arteriosus

Q. A 9-year-old boy has no pulse in the femoral artery, increased blood pressure in the arteries of the upper extremity, and enlarged intercostal veins, Which of the following abnormalities would be suspected?a. Preductal coarctation of aorta b. double aortic archc. Postductal coarctation of aorta d. patent ductus arteriosus

Q. Ductus arteriosus is the derivatives of.a. Rt 6th arch artery b. Lt 6th arch arteryc. Ductus caroticus d. Lt 4th arch artery

Q. Right recurrent laryngeal nerve hooks around.a. Rt subclavian artery b. Rt pulmonary arteryc. Arch of aorta d. Rt brachiocephalic trunk