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

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

Cow (View image)

• The ovaries are two small oval glands, which secrete the ova and are situated a little above the middle of the lateral margin of the pelvic inlet
• It is attached to the lateral abdominal wall by the cranial part of the broad ligament of the uterus - mesovarium
• Each measures about 3.5 to 4 cm long 2.5 cm wide and1.25 cm thick, weighs about 15 to 20 gm
• The size and shape of the ovary are affected by age, ovarian follicle and corpusluteum.
• The ovary presents two surfaces, two borders and two extremities
• The medial and lateral surfaces are smooth and rounded
• The attached or mesovarial border is considered as hilus, which is convex, where the vessels and nerves reach the gland at this border
• The free border is also convex. The cranial tubal extremity is rounded and is related to the fimbriated end of the fallopian tube
• The uterine or caudal extremity is narrower and is connected to the uterus by the ovarian ligament

Species difference

Ewe and Doe

• They resemble in general those of ox with few exceptions
• The ovaries are almond shaped and are half inch or more (1.5cm) long

Mare (View image)

• Bean shaped and much larger, 7 to 8 cm long, 3 to 4 cm thick, weighs 70 to 80 gm
• Situated in the sublumbar region under the 4^th or 5^th lumbar vertebra
• The notch on the free border leads into a depression the ovulation fossa, where ovulation takes place

Sow (View image)

• Ovaries are concealed in a peritoneal pouch called ovarian bursa.
• They are round and irregular lobulated surface seen due to the presence of rounded prominences on its surface.

Bitch (View image)

• Small, elongated, oval and flattened; average length 2 cm
• Situated a little behind (1 to 2 cm) the caudal pole of the corresponding kidney
• The two layers of the ovarian bursa continue to the cornu of the uterus consisting mesosalphinx and the ovarian ligament
• The bursa has a slit-like opening ventrally

Rabbit

• Ovaries are elongated
• Pinkish in colour and about 1cm long and 4mm thick

Hen

• Only left ovary is present since the right one is usually rudimentary
• The left ovary is situated in the dorsal part of the abdominal cavity, attached to the dorsal wall below the last two ribs
• It has the left lung above and in front; the cranial lobe of the kidney above proventriculus and spleen below; caudal venacava medially
• The ovary consists of a mass of loosely connected, yellowish and round objects of different sizes, each containing an ovum
• It is in the form of bunch of grapes in mature stage