VAN 221: Veterinary Splanchnology and Applied Anatomy (1+1)

OVIDUCT
( Cow, Ewe,Doe, Mare, Sow,Bitch, Rabbit, Hen )

Cow (View image)

• Uterine or Fallopian tubes act as excretory ducts of the ovaries since they convey the ova from the ovaries to the uterus
• They are not in direct continuity with the gland but are partly attached to them.
• Each is 20 -25 cm long, extending from the cranial extremity of the ovary to the extremity of the uterine horn at the uterine end
• The tube is rather small but becomes wider and funnel shaped towards the ovaries
• Each is enclosed in a peritoneal fold derived from the broad ligament of the uterus - mesosalphinx
• The uterine extremity communicates with the uterine horn by the large, funnel shaped ostium uterinum tubae while the ovarian end is wide and forms the infundibulum whose margin is irregular and fimbriated
• It presents a small opening - the ostium abdominale tubae by which it communicates with the peritoneal cavity
• The ovarian extremity of the oviduct appears normally to be applied to the ovary, so that the extruded ova pass into it and are conveyed to the uterus

Species difference

Ewe and Doe

• There is no demarcation between the uterine tube and the horn of the uterus
• The tube is very flexuous near the infundibulum (View image)

Mare

• 20 to 25 cm long but more flexuous (View image)
• The oviduct joins the uterine horn very abruptly
• The frimbriae are more extensive and the uterine orifice is minute

Sow

• Less flexuous (View image)
• The fimbriated end has a large abdominal opening

Bitch

• Small and slightly flexuous
• Its abdominal opening is large and uterine opening small
• It passes at first forward in the lateral part of the ovarian bursa and then backward in the medial part of the pouch
• The fimbriated extremity lies chiefly in the bursa but part of it often protrudes through the opening in the bursa

Rabbit

• The oviduct is slender, flexuous about 5 cm length

Hen

• Only the left oviduct is developed. It is dilatable, convoluted tube about 80 cm in length in the laying hen, and extends backwards against the dorsal part of the left body wall in relation to the ilium and ischium
• It opens into the urodeum of the cloaca lateral to the left ureter
• It is suspended between two layers of a fold of peritoneum, which forms the membranous dorsal and ventral ligaments of the oviduct
• The ventral border of the dorsal ligament attached to the duct, while its dorsal border is attached to the dorsal body wall
• The ventral ligament has a free ventral border, which is thick and muscular.
• The cranial end of the oviduct has a delicate funnel shaped structure with long process enclosing the ovary
• Entrance to the oviduct is by a slit-like opening the ovarian end and its exit is into the cloaca.
• The oviduct may be divided into five parts, namely, infundibulum, magnum, isthmus, uterus and vagina each preserving its own structure and physiological function
  • The infundibulum is the funnel-shaped structure, with delicate walls narrowing to a neck of 2.3 cm long. Its function is to grasp the ovum as it is released from the ovary
  • The magnum or albumin secreting part forming the major part of the duct is about 40 cm long and is remarkable for the thickness of the walls
  • It secretes about 40 percent of the albumin of the egg
  • The isthmus about 12 cm long connects the albumin region with a thinner walled uterus
  • The lumen is narrow and secretes the shell membrane and some albumin
  • The thin walled uterus or “shell gland” is wide and about 12 cm long. It terminates in a sphincter muscle
  • The function is to secrete about 40% of total egg albumin, formation the calcareous shell and to certain extent the pigment formation
  • The vagina is 12 cm long and it succeeds the sphincter. The walls are very muscular
  • The outer shell cuticle and perhaps pigment are formed in this part
  • Oviposition takes place in the vagina. It terminates in the cloaca
• The mucous membrane of the oviduct presents longitudinal folds
• The folds are highest in the albumin secreting part; further back the folds are not so high and tend to be transverse or oblique