Chapter 5 Male Sexual Anatomy and Physiology

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Chapter 5Male Sexual Anatomy and Physiology
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Male Sexual Anatomy

• The penis
• foreskin, glans, shaft, root

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Male Sexual Anatomy (cont.)
Fig 5.1a Interior structure of the penis (a)
view from above.
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Male Sexual Anatomy (cont.)

• The penis
• corpus carvernosa
• corpus spongiosum

Fig 5.1b Interior structure of the penis (b)
cross section of the penis
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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
frenulumtwo areas on the penis that harbor a
high concentration of sensitive nerve endings.
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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

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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.
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Male Sexual Anatomy (cont.)

• The testes
• secrete male hormones
• produce sperm
• cryptorchidism undescended testis
• self-exam is recommended

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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.
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Male Sexual Anatomy (cont.)

• The testes
• seminiferous tubules
• site of sperm production
• interstitial cells
• Major source of androgen
• epididymis sperm maturation

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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.
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Male Sexual Anatomy (cont.)

• The vas deferens
• moves sperm from scrotum to ejaculatory duct
  through prostate
• ejaculatory ducts open into the urethra

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Male Sexual Anatomy (cont.)
Fig 5.6 Male sexual anatomy A cross-section side
view of the male reproductive organs.
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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

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Male Sexual Anatomy (cont.)

• The Cowper's glands
• attaches to urethra just below prostate
• secretes fluid before ejaculation
• may contain active, healthy sperm

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Male Sexual Anatomy (cont.)

• Semen (seminal fluid)
• about 1 teaspoon
• 200 to 500 million sperm

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Male Sexual Functions

• Erection
• autonomic nervous system
• arteries expand
• blood outflow cannot keep up with inflow ?
  tumescence
• psychogenic physiogenic factors

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Male Sexual Functions (cont.)
Fig 5.7a Male sexual anatomy during ejaculation
(a) the emission phase.
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Male Sexual Functions (cont.)

• Ejaculation
• spinal reflex triggers two phases
• emission fluid in urethral bulb
• expulsion semen expelled
• retrograde ejaculation
• nocturnal emission

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Male Sexual Functions (cont.)
Fig 5.7b Male sexual anatomy during ejaculation
(b) the expulsion phase.
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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)

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Concerns About Sexual Functioning (cont.)

• Circumcision
• hygienic value risk for STDs?
• medical risks
• AAP moderate opposition
• Phimosis extremely tight foreskin

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Concerns About Sexual Functioning (cont.)
Fig 5.9 Circumcision, the surgical removal of the
foreskin.
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Male Genital Health Concerns

• Penis health-care issues
• cleanliness smegma, infections
• reaction to vaginal secretions
• injuries
• penile cancer

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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 gt 90 if detected early

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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