NOT true regarding Azygos and Hemiazygos Veins are
Left 2nd, 3rd, 4th posterior Intercostal veins form Left Superior intercostal vein that drains into left Brachioaphalic vein.
Right 2nd, 3rd, 4th posterior Intercostal veins form Right Superior intercostal vein that drains into Azygos vein
Right 1st posterior Intercostal Vein drain directly to Right Brachioceplalic Vein
Left 2nd, 3rd, 4th posterior Intercostal veins form Left Superior intercostal vein that drains into Accessory Hemiazygos vein
Left 1st posterior Intercostal Vein drain directly to Left Brachioceplalic Vein