Seminar topic: “Venous drainage of thoracic wall”

LimKuan Yan, 0310445Taylor’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

Intercostal Vein

• Anterior intercostal VeinIn 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

Intercostal Vein

• Posterior intercostal VeinIn each of upper nine spaces• One posterior intercostal vein • One collateral vein

• Each vein accompany the corresponding artery and lies superiorly to the artery

Collateral branch of the posterior intercostal veinPosterior intercostal Vein

V.A.N

Termination of Post. Intercostal VeinPostrior intersotal Veins (P.I.V) P.I.V on the right drain into P.I.V on the left drain into1st • Right brachiocephalic.V • Left Brachiocephalic.V2-4th

(Right side = Joined together and form right sup. Intercostal vein)

(Left side = Joined together and form left sup. intercostal vein)

• Azygous.V • Left Brachiocephalic.V

5-8th • Azygous.V Accesory hemiazygos .V9-11th + subcostal V (12th) • Azygous.V Hemiazygos.V

Right sup. Int. costal vein

Left sup. Int. costal vein

Right subcostal vein Left subcostal vein

Accesory hemizygous V.

Hemizygous V.

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) VeinGeneral 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) VeinCourse• 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

Thank you !!!