Lecture 8: Male and Female Reproductive System

• What is the mechanism through which a species sustains its existence?

  Reproduction
• Why would there be no necessity for subsequent generations if animals lived indefinitely?

  Because existing generations would not die
• What type of reproduction do all mammalian species engage in?

  Sexual reproduction
• How do less evolved species reproduce?

  They reproduce asexually
• What are the main components of the male reproductive system?

  • Testes
  • Associated duct system
  • Male accessory sex glands
  • Penis
• What can be observed in the gross morphology of male reproductive organs?

  Modifications among different species
• What notable differences are evident in the male reproductive system?

  Differences in accessory sex glands
• How does penile morphology vary among male animals?

  It corresponds to differences in mating behavior
• Where are the testes originally located?

  Intraabdominally
• What guides the descent of the testes during embryonic development?

  A structure called gubernaculum
• When do the testes descend in different animals?

  • Before birth: ruminants and pigs
  • Shortly after birth: carnivores
  • 10-14 days after birth: horses
• What is the time frame for testes descent in horses?

  10-14 days after birth
• What is the time frame for testes descent in ruminants and pigs?

  Before birth
• What is the time frame for testes descent in carnivores?

  Shortly after birth
• What is the typical appearance of the scrotum in male dogs?

  Pigmented and covered with few hairs
• Where are the testes located in male dogs?

  Inguinal region
• How are the testes oriented in male dogs compared to bulls, rams, and bucks?

  Horizontally in dogs, vertically in bulls
• How is the scrotum described in bulls, rams, and bucks?

  Long and pendulous
• What divides the scrotum in bulls, rams, and bucks?

  A septum
• How is the hair coverage described in large ruminants compared to small ruminants?

  Sparse in large, dense in small
• Where are the testes located in tomcats?

  Subanal, angled toward anus
• How is the scrotum of a tomcat described?

  Covered with hairs
• Where are the testes located in stallions?

  Inguinal region
• How are the testes oriented in stallions?

  Horizontally
• What is the texture of the scrotum skin in stallions?

  Thin, mostly pigmented, shiny, and oily
• How is the hair coverage described in stallions' scrotum?

  With few fine hairs
• Where are the testes located in boars?

  Perianal, angled toward anus
• How is the scrotum described in adult boars?

  Wrinkled with few hairs
• How is the scrotum divided in boars?

  By a deep groove into left and right halves
• What is the function of the seminiferous tubule?

  It produces sperm in mammals.
• What is the role of the rete testis?

  It collects sperm from seminiferous tubules.
• What is the function of the efferent duct?

  It carries sperm from the rete testis.
• What is the deferent duct's role in mammals?

  It transports sperm to the urethra.
• Where does the deferent duct of male birds enter?

  It enters the urodeum of the cloaca.
• What are the lengths of the epididymis in different animals?

  • Dog: 5-8 m
  • Bull: 40-50 m
  • Stallion: 72-81 m
  • Ram: 47-52 m
  • Boar: 17-18 m
  • Tom Cat: 4-6 m
  • Rooster: 3-4 mm
• What is the ampullary gland?

  Thickened terminal part of the deferent duct
• How does the ampullary gland differ in boars compared to other species?


  Boars have no distinct ampulla
• What is the ejaculatory duct in stallions and bulls?

  Shared passage of deferent and vesicular ducts
• Where does the vesicular gland's excretory duct join the deferent duct in ruminants and horses?

  Shortly before its termination
• How do vesicular glands differ in boars compared to ruminants and horses?

  Boars open separately into the urethra