Intercostal Arteries

INTERCOSTAL ARTERIESINTRODUCTION :- Each intercostal space contains--(1) One posterior intercostal artery with its collateral branch.(ii) Two anterior intercostal arteries- The greater part of the space is supplied by theposterior intercostal artery.POSTERIOR INTERCOSTAL ARTERIESThere are 11 pairs of intercostal arteries, one in each space.They supply the greater part of the intercostal spaces.ORIGINDIPANKARRAY1The 1st and 2nd posterior intercostal arteries arise from thesuperior intercostal anery which is a branch of costocervicaltrunk of the Subclavian artery.2The aorta, 3rd to 11th arteries arise from the descending thoracicRt Sided arteries are longer than those of the left side.COURSE & RELATIONSIN FRONT OF VERIEBRAL COLUMNHuman Anatomy For Exam(1) behind Right posterior intercostal arteries are longer (than the left) passthe esophagus. thoracic duct, azygos vein, andSympathetic ventebral chain but in front of the anterior aspect ofbody.(2) Left posterior intercostal arteries are smaller and pass behindthe hemizygos vein and sympathetic chain, but in front of theSide of vertebral body- INTERCOSTAL ARTERIES2IN THE INTERCOSTAL SPACE(1) In the Intercostal space, the posterior intercostal arterynerve below.lies in the intercostal vein above and the intercostal2The neurovascular bundle in the intercostal space liesbetween the internal intercostal and intercostalisintimus muscles.TERMINATIONDIPANKAR RAYEach posterior intercostal artery ends at the levelof cortochondral junction by anastomosing with the upperanterior intercostal arley of the space.BRANCHESHuman Anatomy For EvenDorsal Branch:- It supplies the spinal card, verlebra and musclesand Skin of neck.Collateral Branch: - It arises near the angle of the rib and runsforwards along the upper burder of the ribartery. below and ends by anastomosing with the lower anterior intercosta)Muscular Branch:- They supply intercostal, pectoral, and serratusanterior muscles.Laveral Cuteneous Branch:- It closely follows the lateral cuteneousbranch of the intercostal nerve.Mammary branches (External Mammary Arteries)They 3rd arise from posterior intercostals arteries of the 2nd,mammary gland.and 4th intercostal spaces and supply the breastRight Bronchial Artery:- It arises from right 3rd posteriorintercostal artery. INTERCOSTAL ARTERIES3ANTERIOR INTERCOSTAL ARTERIESThere are 2 intercostal ameries in each intercostal spare.They are present in the upper nine intercostal spaces only.ORIGINDIPANKAR RAY(1) In 1st - 6th spaces they arise from the internal theracicartery.(2) In 7th and 9th spaces they arise from musculophrenicartery.The 10th and 11th intercostal spaces do not extend forwardenough to have anterior intercostal arteries.Human Anarom,TERMINATIONat Anterior Intercostal artiries are short and endFor Examfollows -the level of costochondral junction as(1) Upper anterior interrostal intercostal artery anastomoses with correspondingposterior artery.(2) Lower branch anterior of intercostal artery anastomoses with collateralthe corresponding posterior intercostal artery.