AS L6

• Asexual reproduction


  Does not require sex organs to facilitate the perpetuation of the species
• Asexual reproduction


  • Unicellular organisms
  • Some species of plants
• Parthenogenetic animals


  Females are able to produce offspring without needing fertilization
• Sexual reproduction


  • Male and female sex organs are involved in the process
  • The ovum and sperm cells fuse to form a new individual

  
• Ovaries


  • Primary sex organs of females
  • Attached by the broad ligament (mesovarium) to the body cavity
  • Comparable to the male testicle and is the site of gamete production

  
• Functions of ovaries


  • Gamete production
  • Secrete estrogen
  • Forms the corpus luteum
• A bovine animal has 20,000 potential eggs per ovary, while a human has around 300,000 potential eggs per ovary

  
• Ova are fully developed at puberty and are not continuously produced as compared to the males

  
• All species contain two functional ovaries except for the hen which only has a left functioning ovary
• Fallopian tube / Oviduct


  • A pair of small tubes leading from the ovaries to the horns of the uterus
  • Oviduct reserves the ova during ovulation and it is the site of fertilization
  • Egg travels from ovary to uterine horn in 3 - 4 days

  
• Parts of the fallopian tube

  • Infundibulum
  • Ampulla
  • Isthmus
• Uterus


  • Site of implantation for fertilized eggs
  • Divided into a body and two horns

  
• Different types of uterus

  • Duplex
  • Bipartite
  • Bicornuate
  • Simplex
• Cervix


  • Considered as the neck of the uterus
  • Its opening, the os uteri, closes when the animal gets pregnant to protect the uterine contents
  • It also facilitates transport of viable sperm through the cervical mucus to the uterus

  
• Vagina


  • The primary copulatory organ of female
  • Serves as the sperm depository area
  • Birth canal at parturition

  
• Vulva


  • Common passage for the products of reproduction and urine
  • Homologous to the scrotum of the male (external covering)
  • Clitoris is a small rudimentary organ homologous to the glans penis of the male (sensitive area)
• Penis


  • The copulatory organ of the male of higher vertebrates
  • Also provides the channel by which urine leaves the body
• Testicles (Testis / Testes)


  • Primary reproductive organ of the male
  • Birds have testes located within the body cavity
  • Livestock have testes located outside the body cavity within the scrotum

  
• Functions of testicles


  • Production of sperm cells
  • Production of male sex hormones (testosterone)
• Bilateral cryptorchid


  When both testes failed to descent to the scrotal sac, sterile
• Unilateral cryptorchid


  When only one of the testes failed to descent, capable of fertilization
• Scrotum


  • A cutaneous sac that serves as the external covering of the testes
  • Protects the testes from direct mechanical injuries
  • Provides an environment which is cooler (6 - 9 °C) than the body temperature; required for normal sperm production
• Seminiferous tubules


  • Found inside the testes responsible for the production of spermatozoa

  
• Leydig cells


  Embedded between the seminiferous tubules of the testes that produce testosterone
• Epididymis


  • Lies upon the surface of the testicle
  • Storage and site of sperm maturation & transportation of spermatozoa

  
• Vas deferens


  • Found at the end of the tail of epididymis
  • Carries sperm from epididymis to the urethra
• Urethra


  • Site where the spermatozoa and accessory fluids are mixed
  • Has a loop called sigmoid flexure (bull, boar, ram and buck)
  • Allows long penis of the animal to retract inside the sheath
• Seminal Vesicles


  • Paired, hollow, and pear shaped in stallion; lobulated in bull, ram and boars; absent in dogs
  • Secretes ascorbic acid, citric acid, acid, soluble phosphorus, seminal fructose, and ergothionine
  • Secretions neutralize urine residues
• Prostate Gland


  • Produces alkaline secretion which gives characteristic odor of semen
  • Secretes fluid that nourishes, protects and stimulates activity of the sperm
• Cowper's gland or Bulbo-urethral gland


  • Small, paired glands located on either side of the pelvic urethra
  • Absent in dogs, extremely large in boars
  • Secretions add volume to ejaculate
• Semen


  Consists the sperm cells plus the secretions of the accessory glands
• In a vasectomized animal, the ejaculate consist only of the secretions of accessory glands, males become sterile without losing libido
• In a castrated animal, both testes are removed, rendering the male sterile with loss of libido
• The lifespan of ejaculated spermatozoa in the female reproductive tract is 20-30 hour in most mammals and 14 days in chicken

  
• Avian ovary


  • This organ forms the ovum (yolk)
  • When yolk reaches the right size, egg production will commence
  • The yolk moves into the fallopian tube
• Avian infundibulum


  • It picks up ovum or yolk from the ovary
  • If mated with a rooster, the egg and sperm will fuse here
• Avian magnum


  • Secretes albumen (egg white)
  • Usually takes around three hours
• Avian isthmus


  • The shell membrane will be secreted to surround and contain the albumen
  • Takes more than an hour to complete
• Avian uterus


  • Also known as shell gland
  • Protein, calcium and other materials including pigments are secreted to form the shell
  • Egg shell is comprised largely of calcium carbonate
  • Usually takes a few hours to complete
• Spermatozoa in the female reproductive tract

  • 20-30 hour in most mammals
  • 14 days in chicken