1. Male Sexual Response Excitement Orgasm: Emission Orgasm: Expulsion Resolution

2. Excitement Visual, mental, physical, stimulus Pelvic nerve stimulates penis Deep artery of the corpus cavernosum dilates and becomes engorged, penis becomes erect Trabecular muscle of erectile tissues relaxes increasing engorgement Bulbourethral gland secretes bulbourethral fluid that neutralizes the urethra

3. Emission Ductus deferens exhibits peristalsis, sperm moved to ampulla, ampulla contracts and sperm is moved to urethra Prostate secretes its part of seminal fluid Seminal vesicles secrete its part of seminal fluid

4. Expulsion Prostate and seminal vesicles increase secretion Urethral sphincter contracts blocking urine from entering urethra Bulbo and ischiocavernosus muscles contract rhythmically and semen is expelled

5. Resolution Pudendal artery constricts reducing blood flow Trabecular muscles contract squeezing blood from tissues Detumescence the gradual softening of the penis returning to a flaccid state Refractory period: can last 10 min to a few hours