Arch of Aorta - Exam Prep Notes

ARCH OF AORTADefinition - It arches over the not of left lung and connectsis situated in superior mediastinum behind the manubrium Sternthe ascending and descending anald Arch of aortaExtent with level:-Begining (A() It Starts as a continuation of theascending aorta at the level 2ndright Stemo castal junction eg Stemal angle.(B) This end lies more in the anterior plane.Human Anatomy ExamForEnd:A At the lower border of T4 Vertebrae, it is continuedasBThis end lies in a more posteriorthe descending thoratic aortaRAY- COURSE -(A) Begins 2nd as a continuation of the ascending aorta behind theright chondrosemal joint.(B) At the commencement, it present a dilation on the right sideknown as the" Bulb of Aorta".(e) At 1st the arch pases upwards. backwards and to theleft, in front of trachea.(D) Then it passes backwards an the left side of trachea.(E) Finally tums downwards and is continuous with thedescending aorta at the lower border of 4th T4FIts termination corresponds with the left 2ndChandrosternal joint. ARCH OF AORTAContConvexitiesThere are 2 convexitiesCA Converity directed upwards - the maximum height of thearch is upto the middle of manubrium Sterni ie 1 cmbelow the jugular notch.(B) Converity directed forwards and to theBRANCHESHuman left ExamBranches (From Rt to left)Occasional Branches1. Brachio-cephalic TrunkArt RAY1) Left Vertebral2. Left Common Carotid2) Left Bronchial3. Left Subelavian Art3) Internal Thoracic Ar.4) Arteria thyroidica ima.5) Inferior thyroid Art.6) Right Subclavian Art(At junction of arch anddescending aonta) ARCH OF AORTAContRELATIONSAnterior and to the leftPosterior to the Right1) Prossed by 4 Nerves andDeep Cardiac Plexus1 Vein.2) Trachea close to bifurcationNerves from before backwards -(A) Left phrenic3) Thoracic duct.(B) Inferior cervical cardiac branchof Left vagus.4) Left Recurrent laryngeal N.5) Left side of T4 Vernebrae.(c) Superior Cervical cardiac branchof Left sympathetic trunk.(p) Left vagus N.the6) Left edge of Oesophagus.BELOW2) Vein - Left superficial intercostal1) Left Principal Bronchusvein - lies posterior to phrenic N.2) Bifurcation of the pulmorarybut superfidid to other 3 nerves.trunk.3) Remains of thymus3) Ligamentum arteriosum4Abore mentioned structures are4) Superficial Cardiac Plexusseparated from manubrianSterni by the anterior partof Left lung and Pleura.5) Left recurrent laryngealnerveAbove(1) Three branches of arch of Aorta(2) Crossing of the left phrenic(A) Brachio-cephalic trunkand left vagus nerves(B) Left common carotid Arterybetween left common(e) Left Sub-clavian Artery.Carotid and left subclavianAll these are crossed infront byarteries; phrenic Crossesleft brachio-cephalic vein.Superficial to vagus.I