L3.2.4: Semen

• Semen: Mixture of sperm and accessory gland secretions.

  ○ Liquid Portion: Transportation medium for nutrients and chemicals that protect sperm

  ○ Fructose from Seminal Vesicle: Provides all necessary energy fuel.

  ○ Antibiotic chemicals: Destroy certain bacteria.

  ○ Hormone relaxin, enzymes: Enhance sperm motility, and substances that inhibit an immune response in the female reproductive tract.

  ○ Alkalinity: Helps neutralize the acidic environment of the vagina.
• Semen → The End Product

  ● Milky white, sticky mixture of sperm and accessory gland secretions

  ● Dilutes sperm to enhance motility
• Semen

  Liquid Portion

  Transport medium for nutrients and chemicals that protect the sperm and aid movement
• Semen

  Fructose (Seminal Vesicle Secretion)

  Provides the sperm’s main energy fuel
• Semen

  Mature sperm

  “Tadpoles” that contain little cytoplasm or stored nutrients
• Semen

  pH Level

  Alkaline (7.2-7.6)

  ● Sperm are sluggish under acidic conditions (under pH 6)

  ● Semen neutralizes the acidic environment (pH 3.5-4) of the vagina
• Semen

  Amount Propelled

  2-5 ml (teaspoon)

  ● Each ml contains 50-150 million sperm
• Semen

  Additional contents

  ● Antibiotic chemicals that destroy bacteria

  ● Hormone: Relaxin

  ● Enzymes that enhance sperm motility

  ● Substances that inhibit immune response in female reproductive tract