Reproductive system (male)

• Male Reproductive System

  Ensures the continued existence of the human species by producing, storing, nourishing, and transporting functional male reproductive cells (gametes)
• Components of the Reproductive System

  • Gonads or reproductive organs that produce gametes and hormones
  • Ducts that receive and transport the gametes
  • Accessory glands and organs that secrete fluids into the ducts
  • Perineal structures that are collectively known as the external genitalia
• Descent of the Testes

  1. Testes form inside the body cavity adjacent to the kidneys

  2. Testes gradually move inferiorly and anteriorly toward the anterior abdominal wall

  3. Gubernaculum testis contracts, moving testes through inguinal canal into scrotum

  
• Spermatic Cords


  Extend between the abdominopelvic cavity and the testes, containing layers of fascia, muscle, blood vessels, nerves, and lymphatic vessels
• Testes


  • Secrete sex hormones called androgens, the main one being testosterone
  • Produce the male gametes, called spermatozoa or sperm, about one-half billion sperm produced each day
• Emission


  Mature spermatozoa travel along a lengthy duct system, where they are mixed with the secretions of accessory glands to form semen
• Ejaculation


  Semen is expelled from the body
• Scrotum


  • Anterior to the anus, and posterior to the base of the penis
  • Sac of loose skin, fascia & smooth muscle, divided into two pouches by a septum
  • Regulates temperature of testes, 2-3 degrees lower than core body temperature
• Seminiferous Tubules


  • Contain sperm forming cells and Sertoli cells (supporting cells)
  • Interstitial cells (Leydig cells) in between tubules secrete testosterone
• Sertoli Cells


  • Extend from basement membrane to lumen, form blood-testis barrier, support developing sperm cells, produce fluid & control release of sperm into lumen, secrete inhibin which slows sperm production
• Sperm Morphology


  • Head contains DNA and the acrosome with enzymes for penetrating the egg
  • Midpiece contains mitochondria to form ATP for energy
  • Tail is flagellum used for locomotion
• Epididymis


  Coiled tube bound to the posterior border of each testis, monitors and adjusts the composition of the fluid produced by the seminiferous tubules, acts as a recycling center for damaged spermatozoa, stores and protects spermatozoa and facilitates their functional maturation

  
• Ductus Deferens


  Begins at the tail of the epididymis, contains a thick layer of smooth muscle that propels spermatozoa, can store spermatozoa for several months

  
• Seminal Vesicles


  Produce a slightly alkaline fluid that mixes with the sperm and becomes part of the semen, protects the sperm from the acidity of the urethra and vagina, contains fructose, prostaglandins, and fibrinogen
• Prostate Gland


  Encircles the proximal portion of the urethra, produces prostatic fluid, a slightly acidic solution that makes up 20–30 percent of the volume of semen, contains seminal plasmin with antibiotic properties
• Cowper's or Bulbourethral Glands


  Produce a mucous-alkaline secretion in the urethra, helps neutralize any urinary acids and lubricates the glans penis
• Penis


  • A tubular organ containing the distal portion of the urethra, conducts urine to the exterior and introduces semen into the female's vagina during sexual intercourse, has a root, body (shaft), and glans penis

  
• Hernia


  A protrusion of parietal peritoneum and viscera, such as the small intestine, through a normal or abnormal opening from the cavity in which they belong, can be corrected through surgery
• Hydrocele


  The presence of excess fluid in membranes, can be confined to the scrotum and distend the tunica vaginalis, or confined to the spermatic cord
• Hematocele


  A collection of blood in the tunica vaginalis that results from rupture of a blood vessel, may produce a scrotal and/or testicular hematoma