Chapter 5 Male Sexual Anatomy and Physiology
Male Sexual Anatomy The penis foreskin, glans, shaft, & root
Male Sexual Anatomy (cont.) Fig 5.1a Interior structure of the penis: (a) view from above.
Male Sexual Anatomy (cont.) The penis corpus carvernosa corpus spongiosum Fig 5.1b Interior structure of the penis: (b) cross section of the penis
Male Sexual Anatomy (cont.) The penis; corona, frenulum Fig 5.2 This figure, a view of the underside of the penis, shows the location of the corona and frenulum—two areas on the penis that harbor a high concentration of sensitive nerve endings.
Male Sexual Anatomy (cont.) The scrotum a sac or pouch with two chambers muscle layer (tunica dartos) pulls sac closer to body in cold temperatures spermatic cord
Male Sexual Anatomy (cont.) Fig 5.3 The scrotum and the testes. The spermatic cord can be located by palpating the scrotal sac above either testicle with thumb and forefinger.
Male Sexual Anatomy (cont.) The testes secrete male hormones produce sperm cryptorchidism: undescended testis self-exam is recommended
Male Sexual Anatomy (cont.) Fig 5.4 Underlying structures of the scrotum. This illustration shows portions of the scrotum cut away to reveal the cremasteric muscle, spermatic cord, vas deferens, and a testis within the scrotal sac.
Male Sexual Anatomy (cont.) The testes seminiferous tubules site of sperm production interstitial cells Major source of androgen epididymis: sperm maturation
Male Sexual Anatomy (cont.) Fig 5.5a Internal structure of a testis. Sperm are produced in the seminiferous tubules and transported to the epididymis, which serves as a storage chamber.
Male Sexual Anatomy (cont.) The vas deferens moves sperm from scrotum to ejaculatory duct through prostate ejaculatory ducts open into the urethra
Male Sexual Anatomy (cont.) Fig 5.6 Male sexual anatomy: A cross-section side view of the male reproductive organs.
Male Sexual Anatomy (cont.) The seminal vesicle secretes 70% of seminal fluid The prostate gland secretes about 30% of seminal fluid alkaline fluid helps counteract acidity
Male Sexual Anatomy (cont.) The Cowper's glands attaches to urethra just below prostate secretes fluid before ejaculation may contain active, healthy sperm
Male Sexual Anatomy (cont.) Semen (seminal fluid) about 1 teaspoon 200 to 500 million sperm
Male Sexual Functions Erection autonomic nervous system arteries expand blood outflow cannot keep up with inflow tumescence psychogenic & physiogenic factors
Male Sexual Functions (cont.) Fig 5.7a Male sexual anatomy during ejaculation: (a) the emission phase.
Male Sexual Functions (cont.) Ejaculation spinal reflex triggers two phases emission: fluid in urethral bulb expulsion: semen expelled retrograde ejaculation nocturnal emission
Male Sexual Functions (cont.) Fig 5.7b Male sexual anatomy during ejaculation: (b) the expulsion phase.
Concerns About Sexual Functioning Penis size symbol of virility erect penises show less variation than flaccid size not related to sexual satisfaction penile augmentation genital retraction syndrome (koro)
Concerns About Sexual Functioning (cont.) Circumcision hygienic value & risk for STDs? medical risks AAP: moderate opposition Phimosis: extremely tight foreskin
Concerns About Sexual Functioning (cont.) Fig 5.9 Circumcision, the surgical removal of the foreskin.
Male Genital Health Concerns Penis health-care issues cleanliness: smegma, infections reaction to vaginal secretions injuries penile cancer
Male Genital Health Concerns (cont.) Testicle health-care issues testicular cancer rare, but more common in young men (15 to 34 years) sign: hard or irregular mass Survival > 90% if detected early
Male Genital Health Concerns (cont.) Prostate health-care issues prostate diseases prostatitis: enlarged & inflamed benign prostatic hyperplasia prostate cancer PSA test Treatment options for prostate cancer