P ersistent Erection, also known as Priapism or Persistent Genital Arousal Syndrome (PGAS), prevents the penis from returning to its normal, flaccid state. When an erection stays hard for extended periods, men can feel pain at the tip or base. Start studying Med Term CH 7 Male reproductive system. Learn vocabulary, terms, persistent abnormal erection of the penis accompanied by pain and tenderness. The penis is an external organ in the male reproductive system. Disorders which can affect the penis include priapism, balanitis, penile cancer, erectile dysfunction, and ejaculatory disorders. Examine the causes and treatments. The penis is one of the external structures of the male reproductive.