male reproductive system

• primary reproductive organ (male)

  testes

  
• What do primary sex organs do?


  produce gametes (sex cells)

  secrete steroid sex hormones
• What hormones do the testes secrete?

  androgens (testosterone)
• accessory reproductive organs


  ducts, glands, and external genitalia

  
• testes


  male gonads, produce sperm and testosterone
• Scrotum


  External sac of skin and superficial fascia that contains the testes and hangs outside the abdominopelvic cavity

  
• path of sperm through ducts

  Epididymis → ductus deferens → ejaculatory duct → urethra

  
• Why are the testes outside of the body?

  sperm require cooler temperatures than found in the body cavity in order to develop properly (3 degrees lower)
• What two muscles regulate testicular temperature?

  Dartos muscle

  Cremaster muscle
• Dartos muscle


  smooth muscle that wrinkles scrotal skin to pull the scrotum close to body

  
• Cremaster muscle


  bands of skeletal muscle that elevate testes

  
• two tunics of the testes

  1. tunica vaginalis

  2. tunica albuginea
• tunica vaginalis


  outer layer of the testes
• tunica albuginea


  inner layer of testes; fibrous capsule

  
• septa of testes


  extensions of the capsule that extend into the testis and divide testes into lobules
• seminiferous tubules


  Tightly coiled structures that act as sperm-forming factories

  
• lobules of testes


  contain 1-4 coiled seminiferous tubules which will produce sperm
• interstitial endocrine cells


  surrounding seminiferous tubules and produce androgens

  
• male duct system


  Epididymis

  Ductus deferens

  Ejaculatory duct

  Urethra

  
• What is the function of the male duct system?

  Ducts carry sperm from the testes to body exterior

  
• Epididymis


  A 6m long, coiled duct on the outside of the testis in which sperm are stored and matured

  
• microvilli (epididymis)


  absorb testicular fluid and pass nutrients to stored sperm

  
• What is the process of sperm in the epididymis?

  1. nonmotile sperm enter

  2. sperm pass through slowly

  3. become motile

  4. stored for several months

  
• ductus deferens


  Carries sperm from the epididymis to the ejaculatory duct

  
• ejaculatory duct


  duct formed by the union of the vas deferens with the duct of the seminal vesicle; its fluid is carried into the urethra

  
• urethra


  Extends from the base of the urinary bladder to the tip of the penis

  
• What does the male urethra carry?

  urine and sperm
• three regions of the male urethra

  1. prostatic urethra

  2. membranous urethra

  3. spongy (penile) urethra

  
• prostatic urethra


  surrounded by prostate

  
• membranous urethra


  from prostatic urethra to penis

  
• spongy urethra


  runs the length of the penis

  
• vasectomy


  The cutting and ligating ductus deferens; nearly 100% effective form of birth control

  Cut stop sperm from entering the ejaculatory duct

  
• accessory glands (male)


  1. seminal vesicles

  2. prostate

  3. bulbourethral glands

  
• What is semen?


  a milky-white mixture of sperm and accessory gland secretions
• fructose (sperm)


  used for ATP production; protects and activates sperm; facilitates sperm movement

  
• What pH is sperm?

  alkaline to neutralizes acidity of male urethra and female vagina
• How do sperm become motile?

  1. Fructose

  2. Relaxin (hormone)

  3. Enzymes
• Prostaglandins


  decrease viscosity of mucus in the cervix; stimulate reverse peristalsis in uterus
• clotting factors


  coagulate semen initially to prevent draining out; then are liquefied by fibrinolysin
• seminal vesicles


  Located at the base of the bladder

  Produces thick, alkaline, yellowish secretion (60% of semen)