31. More specifically, the tube is inserted into the 5th intercostal space slightly anterior to the mid axillary line. 32. Posteriorly, the second rib is connected with the vertebral column by the intercostal veins and arteries and intercostal nerve. 33. Posteriorly, the second rib is connected with the vertebral column by the intercostal veins and arteries and intercostal nerve. 34. The esophagus also lies in front of parts of the hemiazygos veins and the intercostal veins on the right side. 35. Other air sacs are located between the sternum and the pectoral muscles and between the ribs and the intercostal muscles. 36. They anastomose with the lower intercostal , the iliolumbar, the deep iliac circumflex, and the inferior epigastric arteries. 37. It is sourced from the segmental medullary arteries and the segmental spinal arteries which are sourced from the intercostal arteries. 38. Or it can have been a passing cramp of some intercostal muscle, which can occasionally occur without discernible trigger. 39. The parasternal lymph nodes drain into the bronchomediastinal trunks, in a similar fashion to the upper intercostal lymph nodes. 40. The perforating branches of the internal thoracic artery pierce through the internal intercostal muscles of the superior six intercostal spaces.
