Also known as the testicular a., the internal spermatic artery is a paired, oxygen-rich blood vessel that supplies the testicles, the ureter, and the renal fat. Each one of them originates straight from the anterior wall of the abdominal aorta, right below the point of origin of the renal artery. In few cases both testicular arteries arise from a common trunk. In women, it is called the ovarian artery, which supplies the ovaries.
As it runs down and laterally, the internal spermatic artery travels over the psoas major muscle, crossing the ureter and the external iliac artery. Having passed the inguinal canal, it runs into the scrotum, where it divides into several smaller arteries that supply the parenchyma of the testis and the epididymis, which is a convoluted duct lying on the posterior aspect of the testis. Along its long course, the testicular artery sends small branches to the renal fat and the ureter (ureteric branches).
Below, diagram of the abdominal aorta, showing the testicular and the inferior mesenteric artery. As it travels down laterally, the testicular artery pierces the mesentery (sheet of connective tissue). Then it extends down behind it out of sight.
