VGO 511: Veterinary Andrology and Reproductive Techniques (1+1)

SEMINAL VESICLE

• Paired accessory sex gland located in the floor of the pelvis, dorsal and lateral to the ampulla or neck of the bladder.
• In ruminants and boar, it is a lobulatory gland in which lobulation have small central dilatation.

Name of the seminal vesicle in all domestic animals is vesicular gland except in stallion.

• In stallion - large central dilatation is present.
• In stallion, structure of seminal vesicle is more bladder like and glands are located on the walls.
• Secretion of the seminal vesicle adds nutrients, volume and buffer to the semen.
• They open in the pelvic urethra in close proximity with the opening of vas deferens (Colliculus seminalis )

 

Seminal vesicle in all domestic animals do not store spermatozoa

Function

• The salient physiological functions of seminal vesicle are
  • To produce vital biochemical secretion.The seminal vesicle is the site for production of fructose and citric acid. The fructose is the main source of nutrition /energy for the spermatozoan motility. The remaining other biochemicals are also essential for spermatozoal survivability and maintenance.
  • To secrete vesicular fluid. The seminal vesicle is the main source for the production of liquid part of ejaculate. The vesicular fluid in the liquid state is the main source of flow-current and gives impetus for floating vesicular motion due to surface tension of its liquid state, which helps the male gamete during its swimming in the liquid seminal plasma by propelling of spermatazoal locomotory apparatus through dynamic energy.
  • The liquid secretion of seminal vesicle helps in lubrication of urethra for movement of spermatozoa.
  • Final volume of semen is related to the quantity of secretion of seminal vesicle.

Blood supply

• Both middle rectal artery and the inferior vesicle artery are the arterial source of seminal vesicle which is the branch of internal iliac artery.

Nerve supply

• The muscular wall of the seminal vesicle is provided with a plexus of nerve fibres and contain small sympathetic ganglion.

Species wise anatomy (Click on the images for detailed pictures)

Bull Vesicular glands are lobulated, 10-15 cm, long and 2-4 cm, in diameter .
Stallion Seminal vesicles are smooth, 15-20 cm, long and about 2.5-5 cm, in diameter. A small portion of seminal vesicle is covered with peritoneum in case of bull and stallion.
Boar Vesicular glands are proportionately very large, 12-15 cm, long, 5-8 cm wide and 5-8 cm, thick. They cover the caudal portion of the bladder and extend in to the abdominal cavity. The volume of ejaculated semen is maximum in porcine species which is probably due to comparatively heavier and enlarged size of seminal vesicle in boar. It might be a characteristic features of species.
Ram and Buck Resemble those of the bull .
Dog and Cat Seminal vesicle absent in dog and cat

Biometry of Seminal Vesicle in Different Species

Species	Length (cm)	Breadth (cm)	Thickness (cm)	Weight (gm)
Bull	10 - 15	2 - 4	2	75
Stallion	15 - 20	2. - 5	5	-
Ram	12 - 15	5 - 8	4	200
Boar	4 - 5	2	1.5	5