Chapter 4 Male Sexual Anatomy and Physiology

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Chapter 4 Male Sexual Anatomy and Physiology
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The Penis

• External anatomy of the penis includes
• Foreskin, glans, shaft, root

Why is it important to conduct regular genital
self-exams, and what should a man look for?
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The Penis
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The Penis

• Internal anatomy of the penis includes
• Cavernous bodies (corpora cavernosa)
• Spongy body (corpus spongiosum)
• Penile urethra

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The Penis
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The Penis

• Corona
• Frenulum
• Glans

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The Penis
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The Scrotum

• Sac or pouch with two chambers
• Muscle layer (tunica dartos)
• Pulls sac closer to body in cold temperatures
• Spermatic cord

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The Penis
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The Testes

• Testes
• Secrete male hormones
• Produce sperm
• Cryptorchidism
• Undescended testis
• Self-exam is recommended

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Underlying Structures of the Scrotum
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The Testes

• Seminiferous tubules
• Site of sperm production
• Interstitial cells
• Major source of androgens
• Epididymis
• Sperm maturation

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Internal Structure of a Testis
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The Vas Deferens

• Move sperm from scrotum to ejaculatory duct
  through prostate
• Ejaculatory ducts open into the urethra

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Male Sexual Anatomy
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Male Sexual Anatomy

• Seminal Vesicle
• Secretes 70 of seminal fluid
• Prostate Gland
• Secretes 30 of seminal fluid
• Cowpers Glands
• Secretes fluid before ejaculations
• May contain active, healthy sperm
• Semen (seminal fluid)
• Volume is about 1 teaspoon
• 200 to 500 million sperm

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Erection

• Coordinated by autonomic nervous system
• Arteries expand
• Blood out flow cannot keep up with in flow
• Capacity for erection is present at birth
• Psychogenic and physiogenic erections

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Ejaculation

• Spinal reflex triggers two phases
• Emission
• Fluid in urethral bulb
• Expulsion
• Semen expelled
• Retrograde ejaculation
• Nocturnal ejaculation

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Male Sexual Anatomy during Ejaculation
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Concerns about Sexual FunctioningPenis Size

• Penis size is seen as a symbol of virility
• Erect penises show less variation than flaccid
• Size NOT related to sexual satisfaction
• Penile augmentation
• Genital retraction syndrome

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Concerns about Sexual Functioning

• Phimosis
• Extremely tight foreskin
• Circumcision
• Hygienic value risk for STIs question
• Medical risks
• AAP moderate opposition
• Data not significant to recommend routine
  procedure

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Male Circumcision
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Male Genital HealthPenis Health-Care Issues

• Cleanliness
• Smegma
• Infections
• Reaction to vaginal secretions
• Injuries
• Penile cancer

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Male Genital HealthTesticle Health-Care Issues

• Testicular Cancer
• More common in young men (20 to 35 years old)
• Risk factors
• Hard or irregular mass in testes
• Survival is greater than 90 if detected early

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Male Genital HealthProstate Health-Care Issues

• Prostate diseases
• Prostatitis
• enlarged and inflamed
• Benign prostatic hyperplasia
• Prostate cancer
• PSA test
• Treatment options for prostate cancer