Reproductive Flashcards
Reproductive System
The only organ system not responsible for survival of the individual
Embryonic Development
- Begins at approximately 3-4 weeks gestation
- Gender is undifferentiated and can go either way (anatomically and physiologically)
- Predetermined genetically, but depends on early signalling pathways
Gonad: (Testis)
Primary organ, responsible for sperm production and development/maintenance of secondary sex characteristics
- as sperm are produced they move into a tubular network (rete testis)
- cilia carries the sperm through efferent ductules into the epididymis
Parts of the Testis
- Seminiferous tubules
- Sertoli cells
- Spermatozoa
- Interstitial cells (of Leydig)
Seminiferous Tubules
Highly coiled “sperm factories” sealed by the blood testis barrier
- located in testicular lobules
Sertoli Cells
(Nurse, Sustentacular cells)
- form the blood testis barrier and support sperm development
Spermatozoa
Mature sperm cells formed by:
- meiosis: a specialized type of cell division that splits the chromosome number in half
- spermiogenesis: morphological changes leading to characteristics of spermatozoa
Interstitial Cells (of Leydig)
- between seminiferous tubules
- secrete testosterone
Epididymis
- a comma shaped organ that arches over the posterior and lateral side of the testis
- stores spermatozoa until ejaculation or death
Vas Deferens
- extends from the epididymis duct to the prostatic urethra
- passes posterior to the urinary bladder
- most located in the spermatic cord with spermatic blood vessels and nerves
- passes near the seminal vesicles to end at the ejaculatory duct
Seminal Vesicles
- bilateral, located on the posterior/inferior aspect of the urinary bladder
- produce 60% of semen
Prostate
- located inferior to the urinary bladder
- surrounds the prostatic urethra
- the size and shape of a chestnut
- secretes about 1/3 of semen
Bulbourethral (Cowper’s)Gland
- located inferior to the Prostate and superior to the Penis
- in the urogenital diaphragm
- secretes an alkaline substance prior to ejaculation
- neutralizes acid from urine
Penis
Erectile tissue cavernous tissue that becomes engorged with blood during erection
• corpus spongiosum: surrounds the penile urethra
• corpora cavernosa: 2, located on the dorsal aspect of the penis
• glans: the enlarged tip of the penis
• prepuce: a cuff of loose skin that covers the glans (removed during circumcision)
Scrotum
- a thin sac of skin, superficial fascia and smooth muscle (dartos)
- holds the testes outside of the body
- reducing temperature