Life Sciences Grade 12 Notes: Male Reproductive System
1. Anatomy of the Male Reproductive System
The male reproductive system is composed of internal and external organs designed to
produce, maintain, and transport sperm and protective fluid (semen).
• Scrotum: A sac of skin that houses the testes. It sits outside the abdominal cavity
to maintain a temperature approximately 2 to 3 degrees Celsius lower than the
core body temperature, which is essential for the production of viable sperm.
• Testes: Two oval-shaped glands where spermatogenesis occurs. They contain
highly coiled tubes called seminiferous tubules.
• Epididymis: A long, coiled tube sitting on top of each testis where sperm are
stored and undergo maturation to become mobile.
• Vas deferens (Sperm duct): A muscular tube that carries sperm from the
epididymis to the urethra during ejaculation.
• Urethra: A common duct for the passage of both urine and semen (though never
simultaneously).
• Penis: The external intromittent organ that facilitates the transfer of sperm into
the female reproductive tract.
• Accessory Glands:
o Seminal Vesicles: Produce a fluid rich in fructose to provide energy for
sperm.
o Prostate Gland: Secretes an alkaline fluid that protects sperm against the
acidic environment of the vagina and enhances sperm motility.
o Cowper’s Gland (Bulbourethral gland): Produces a clear mucus that
lubricates the urethra and neutralizes traces of acidic urine.
, 2. Microscopic Anatomy of the Testis
The internal structure of the testis is specialized for the dual functions of gamete
production and hormone secretion.
• Seminiferous Tubules: Lined with germinal epithelium cells that divide by
meiosis to produce sperm.
• Sertoli Cells: Specialized cells located within the tubules that provide nutrients
and mechanical support to the developing sperm cells.
• Interstitial Cells (Cells of Leydig): Found in the tissue spaces between the
seminiferous tubules. These cells are responsible for secreting the hormone
testosterone.
1. Anatomy of the Male Reproductive System
The male reproductive system is composed of internal and external organs designed to
produce, maintain, and transport sperm and protective fluid (semen).
• Scrotum: A sac of skin that houses the testes. It sits outside the abdominal cavity
to maintain a temperature approximately 2 to 3 degrees Celsius lower than the
core body temperature, which is essential for the production of viable sperm.
• Testes: Two oval-shaped glands where spermatogenesis occurs. They contain
highly coiled tubes called seminiferous tubules.
• Epididymis: A long, coiled tube sitting on top of each testis where sperm are
stored and undergo maturation to become mobile.
• Vas deferens (Sperm duct): A muscular tube that carries sperm from the
epididymis to the urethra during ejaculation.
• Urethra: A common duct for the passage of both urine and semen (though never
simultaneously).
• Penis: The external intromittent organ that facilitates the transfer of sperm into
the female reproductive tract.
• Accessory Glands:
o Seminal Vesicles: Produce a fluid rich in fructose to provide energy for
sperm.
o Prostate Gland: Secretes an alkaline fluid that protects sperm against the
acidic environment of the vagina and enhances sperm motility.
o Cowper’s Gland (Bulbourethral gland): Produces a clear mucus that
lubricates the urethra and neutralizes traces of acidic urine.
, 2. Microscopic Anatomy of the Testis
The internal structure of the testis is specialized for the dual functions of gamete
production and hormone secretion.
• Seminiferous Tubules: Lined with germinal epithelium cells that divide by
meiosis to produce sperm.
• Sertoli Cells: Specialized cells located within the tubules that provide nutrients
and mechanical support to the developing sperm cells.
• Interstitial Cells (Cells of Leydig): Found in the tissue spaces between the
seminiferous tubules. These cells are responsible for secreting the hormone
testosterone.
