the middle rectal artery was present in 56.7 % of the cases , bilaterally ( 36.7 % ) or unilaterally ( 20 % ) , originating from the internal pudendal ( 40 % ) , inferior gluteal ( 26.7 % ) , internal iliac ( 16.8 % ) , and less frequently from other pelvic branches .
C0020889
iliac
C0030797
pelvic