Chapter 28: The Reproductive System Flashcards
What are the accessory ducts of the male reproductive system?
- epididymis
- ejaculatory duct
- vas deferens
- urethra
What are the accessory glands of the male reproductive system? How much seminal fluid does each one add?
Seminal vesicles (2) - adds 60% of semen
Prostate gland (1) - adds 35% of semen
Bulbourethral glands (2) - adds 5% of semen
What temperature in the scrotum is needed for sperm production?
Approx. 34°C
(At least 3° below body temp, so it must be slightly colder)
Where in the testis is sperm produced? In what tunica?
In the seminiferous tubules held in the tunica albuginea
What are the 2 types of cells in the seminiferous tubules? What do they do?
- Spermatogenic cells - give rise to sperm
-
Sertoli cells
- nourish and protect spermatogenic cells
- control release of sperm into lumen
- secretes androgen, and inhibin
What do leydig cells do?
Produce the testosterone hormone to begin spermatogenesis
How long does spermatogenesis take?
About 64-72 days
Dartos muscle
Smooth muscle within the scrotum that contracts when cold to wrinkle the scrotal skin and reduce heat loss.
Cremaster muscle
Skeletal muscle in the scrotum which contracts when cold to move the testes closer to the body to retain heat
What are the steps of spermatogenesis?
Spermatogonia (2n) divide by mitosis to make primary spermatocytes (2n). Those divide through meiosis I to make secondary spermatocytes (n), then divide by meiosis II to become spermatids (n). Those develop into spermatozoa (n)
What are the 3 parts of a spermatozoa? (Sperm)
- Head - contains nucleus
- Midpiece - contains mitochondria
- Tail - is a flagellum for movement
What hormone stimulates leydig cells to release testosterone?
Luteinizing hormone (LH)
What hormone stimulates Sertoli cells to release androgen binding protein to bind testosterone
Follicle stimulating hormone (FSH)
What hormone stimulates the release of LH and FSH?
Gonadotropin releasing hormone
What does the hormone inhibin do in regards to spermatogenesis?
- Stops the production of FSH
- lowers amount of LH being released when testosterone levels are too high.