FEMALE REPRODUCTIVE SYSTEM-RABBIT

The female reproductive organs include a pair of ovaries, a pair of oviducts, a pair of uteri, vagina, vestibule, clitoris and some accessory glands.

 

1. OVARIES

  • The two ovaries are small, whitish, oval bodies, about 2 cm long.
  • They are found behind the kidneys, each ovary attached to the dorsal abdominal wall by a double fold of peritoneum called mesovarium.
  • From the surface of ovaries project several blister-like, small, rounded, semitransparent projections, called ovarian or Graafian follicles, each containing a developing ovum.
  • Histologically, the section of a rabbit ovary shows a peripheral layer of germinal epithelial cells surrounding a dense mass of connective tissue fibres, called stroma, containing blood andlymph vessels and nerve.
  • Stroma contains groups of actively dividng germinal cells, called follicle in various stages of development.
  • In each follicle, a single cell enlarges firswhile others surround and nourish it. It ultimately beomes oocyte orovum.
  • The mass of cells around oocyte is known as discusproligerous.
  • When ripe, the follicles are known as Graafian follicles, which project from thesurface of ovary as minute bumps.
  • Each graafian follicle contains a large fluid - filled follicular cavity.
  • The cells lining the cavity are termed membrana granulosa.
  • The fully mature oocyte is surrounded by a thick transparent membrane called zona pellucida containing yolk and fat droplets.
  • It is covered by another striated layer ot columnar cells, called corona radiata.

Female-reproductive-system-rabbit

  • In the stroma there are also found groups of interstitial cells which produce sex hormones (oestrogen).
  • Eventually each mature follicle bursts to liberate the oocyte into body cavity, a process known as ovulation.
  • The follicular cells remaining behind divide rapidly to form a yellowish solid mass of cells called corpus luteum.
  • During pregnancy it serves as a temporary endocrine gland secreting a hormone (progesterone).
  • It causes uterus to enlarge to receive the growing foetus and stimulates lactation.
  • If ovum is not fertilized, corpus luteum gradually disappears leaving a scar called corpus albicans.

 

2 OVIDUCTS

  • Each oviduct opens anteriorly, close to the outer border of the ovary of its side, by a wide funnel called fallopian or oviducal funnel.
  • The opening of funnel, or ostium, is provided with many cilia to receive the minute ova released from the ovary.
  • Funnel leads into the upper part of oviduct. It is a short, narrow, coiled and internally ciliated duct called fallopian tube. Ova pass. through this tube by ciliary action and fertilization also occurs here.
  • The fallopian tube is followed by a much wider, longer convoluted, thick walled muscular tube the uterus.
  • It is richly vascular and highly distensible and attached to the dorsal abdominal wall by a mesentery.
  • Fertilized ova or zygotes get implanted on the uterine wall to develop into embryos or foetuses, each attached to the placenta by an umbilical cord.

3. VAGINA AND VESTIBULA

  • The uteri of both the sides meet into a long wide, median duct, the vagina, lying dorsally upon the urinary bladder.
  • It opens posteriorly into the neck of bladder to join the urethra forming a short narrow common urinogenital canal or vestibule.
  • It runs backwards ventral to the rectum and opens to the exterior by a slit-like aperture, the vulva.
  • The vagina serves to receive the penis of the male during copulation.

 

4. CLITORIS

  • From the anterior wall of vulva projects a small erectile knob-like clitoris.
  • It is regarded homologous with the male penis since it contains a pair of erectile tissue, the corpora cavernosa.
  • But the urethra does not pass through the clitoris.

 

5. ACCESSSORY GLANDS

  • In the female rabbit, there is no prostate gland.
  • A pair of small Bartholin’s glands or Cowper’s glands lies embedded in the dorsal wall of vestibule.
  • Their viscid secretion lubricates the vaginal passage. The perineal and rectal glands are as in the male.

No comments:

Post a Comment