Seminar topic: “Venous drainage of thoracic wall” LimKuan Yan, 0310445 Taylor’s University MBBS, Batch 5.

Veins that we going to discuss today Internal thoracic vein Intercostal vein (Ant & Post.) Azygos Vein Hemiazygos vein Accessory vein

Internal Thoracic Vein the (Internal Mammary Vein) Is a vessel that drains the chest wall and breasts. Bilaterally, it arises from the superior epigastric vein, Accompanies the internal thoracic artery along its course and terminates in the brachiocephalic vein.

Intercostal Vein

Anterior intercostal Vein In each of the upper nine spaces Two anterior intercostal veins They accompany the corresponding arteries Termination of Ant. Intercostal.V In upper 3 spaces, the veins end in the internal thoracic vein In upper 4-6 spaces, the veins end in vena comitantes accompanying internal thoracic artery. In lower 7-9 spaces, the viens end in vena comitantes accompanying muculophrenic artery

Musculophrenic artery & Internal Thoracic artery

Posterior intercostal Vein In each of upper nine spaces One posterior intercostal vein One collateral vein Each vein accompany the corresponding artery and lies superiorly to the artery V.A.N Collateral branch of the posterior intercostal vein Posterior intercostal Vein

Termination of Post. Intercostal Vein Postrior intersotal Veins (P.I.V) P.I.V on the right drain into P.I.V on the left drain into 1st Right brachiocephalic.V Left Brachiocephalic.V 2-4th (Right side = Joined together and form right sup. Intercostal vein) (Left side = Joined together and form left sup. intercostal vein) Azygous.V 5-8th Accesory hemiazygos .V 9-11th + subcostal V (12th) Hemiazygos.V Left sup. Int. costal vein Right sup. Int. costal vein Accesory hemizygous V. Hemizygous V. Right subcostal vein Left subcostal vein

Azygos (Unpaired) Vein General info Azygos vein drain the thoracic wall and the upper lumbar region. It forms and important channel connecting the sup. & inf. Vanae cavae The vein occupies the upper part of post. Abdominal wall and post. Mediastinum It connects portal venous system to caval venous system. Formation The azygos.V is formed by union of Lumbar azygos.V (Abdominal part of azygos.V) Lies to the right of lumbar vetebrae It’s lower end communicates with IVC Ascending lumbar.V (Formed by verticle anastomoses that connect the lumbar vein) Right subcostal.V (Accompany by right subcostal artery)

Azygos (Unpaired) Vein Course Ascends up Pass through the aortic opening of the diaphragm Enter throax Continue ascend up to T4 Form arches forward over the root of the right lung Joined the post aspect of sup.vena cava (just before piercing into the pericardium) THE END Relation Ant = Oesophagus Post = Lower 8 throcic vetebraes ( T5-T12) = Right post. Intercostal arteries Right = Right lung = Pleura Left = (lower part) => Thoracic duct + aorta = (upper part) =>Oesophagus + trachea + vagus nerve

Hemiazygos (Inferior hemiazygous) Vein General info It is mirror immage of lower part of the azgos vein. Formation Hemiazyos vein is formed by union of Left lumbar azygos.V Left ascending lumbar.V Left subcostal.V

Hemiazygos (Inferior hemiazygous) Vein Course Ascend upward Pierce the left crura of the diaphragm Go upward along with the left side of the vetebrae Overlapped by aorta At T9 go right side of the vetebrae Passes behind oesophagus Joins the azygos.V THE END Tributaries 9th to 11th left post. Intercostal.V Oesophagus.V

Accessory (Superior hemiazygos) Vein General info It is the mirror image of upper part of azygos vein. Course Begin with medial end of 4th or 5th intercostal space Descends downward on the left side of the vertebral column At the level of T8,it turns to the right side of vetebrae Passes behind the aorta & thoracic duct Join with azygos.V THE END Tributaries 5th to 8th left post. Intercostal.V

References

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