sex 3 men

Sex organs of the male : Sex organs of the male External genitals Internal reproductive structures


External genitals : External genitals Scrotum Cremaster muscles (Skeletal muscle) Dartos muscles (Smooth muscle) Spermatic cord Cremasteric muscles Vas deferens Blood vessels (testicular artery, spermatic vein) Nerves


Testes: Hormones and sperm/Testimony : Testes: Hormones and sperm/Testimony Lobes of seminiferous tubules Seminiferous epithelium Spermatogonia Spermatocytes Sertoli cells and SCO syndrome Leydig cells/interstitial cells Vas efferens/vasa efferentia: Peristalsis Epididymis Vas deferens: Vasectomy


Testicular conditions : Testicular conditions Varicocele Hydrocele Spermatocele Epididymal cyst Testicular torsion Cryptorchidism Testicular cancer A young man’s disease Rare but lethal if not treated promptly Possibly caused by a mold infection in utero


Genital self-examination : Genital self-examination Check skin for bumps, sores, and blisters. Include the glans Testicular self-examination Conduct when cremasteric muscles are relaxed Look for pea-sized bump, full or heavy feeling in scrotum, swelling or tenderness AFP test Alpha-fetoprotein levels in the blood are increased by tumors of the testes, ovaries, or liver.


Other conditions : Other conditions Urethritis Benign Prostatic Hyperplasia Prostate cancer Digital rectal examination PSA test Phimosis Cramping Priapism


The penis : The penis Glans Corona and frenulum Urethra Prepuce or foreskin Shaft Corpora cavernosa, surrounded by tunica albuginea Corpus spongiosum Crus/crura


Erection : Erection Levator ani muscle group: a hammock Bulbocavernosus/bulbospongiosus: Contributes to erection, ejaculation, and feelings of orgasm. Ischiocavernosus can influence intracorporeal pressure by retarding venous return; stabilizes erection Neural stimulation: nitric oxide (NO) Sexual arousal in brain releases nitric oxide in corpora cavernosa of penis NO triggers the enzyme guanylate cyclase Activates cyclicGMP


Erection, continued : Erection, continued cGMP causes smooth muscle tissue to relax Arteries dilate Increased arterial blood inflates the penis Rising blood pressure constricts veins Arousal--andgt;Nitric oxide release in penis --andgt;activation of cGMP--andgt;increased blood flow--andgt;erection Physical stimulation triggers sacral reflex


What goes wrong? : What goes wrong? Inattention lowers nitric oxide release cGMP is quickly metabolized by PDE5, an enzyme cGMP activation must at least equal metabolization Sildenafil (Viagra) inhibits metabolizing enzyme PDE5 Diabetes, artery blockage, nerve damage Appearance and angles: Peyronie’s disease


Circumcision : Circumcision The procedure Religious reasons Judaism and Islam Christianity Cultural reasons U.S.A. vs Canada, Great Britain Health reasons Urinary tract infections in infancy STD susceptibility


Internal reproductive tracts : Internal reproductive tracts Vas deferens/Vasa deferentia Ejaculatory duct Seminal vesicles Urethra Prostate: Combined muscle and gland Semen Cowper’s/bulbourethral glands


Sperm production : Sperm production LH/ICSH (Interstitial Cell Stimulating Hormone) FSH stimulates spermatocytes, which divide into spermatids with 23 chromosomes Sperm Head: Genetic material, pheromone sensors Midsection Tail


Ejaculation : Ejaculation Spinal reflex: Ejaculation Parasympathetic Nervous System controls erection Sympathetic Nervous System controls ejaculation Thus, anxiety or threat interferes with erection, but promotes ejaculation: Ejaculatio praecox, or premature ejaculation.


Stages of ejaculation : Stages of ejaculation Emission stage The urethral bulb and ejaculatory inevitability Controlled by lumbar ejaculatory center Expulsion stage Usually accompanied by orgasm Controlled by sacral ejaculatory center Retrograde ejaculation


Illustrations deleted to respect copyright : Illustrations deleted to respect copyright


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