A medical syringe having a barrel with a substantially cylindrical, longitudinally extending fluid chamber, a needle retraction cavity substantially coextensive in length with the fluid chamber and disposed adjacent and parallel to the fluid chamber, and at least one substantially flat, outwardly facing display area configured to receive and display an array of volumetric measuring indicia in alignment with and proximal to the fluid chamber.一種醫療注射器，其具有：筒腔，其具有大致圓柱形、縱向延伸的流體室；針縮回腔，其在長度上與流體室大致共同延伸，並且配置成相鄰且平行於流體室；以及至少一大致平坦、面向外的顯示區域，其建構成接收和顯示對齊且接近流體室之體積測量標記的陣列。
