Male accessory glands ( MAG) are the seminal vesicles, prostate gland, and the bulbourethral glands.[Li-Ping Wang, Jun Shen, Lin-Quan Ge, Jin-Cai Wu, Guo-Qin Yang and Gary C. Jahn. Insecticide-induced increase in the protein content of male accessory glands and its effect on the fecundity of females in the brown planthopper Nilaparvata lugens Stål (Hemiptera: Delphacidae). Crop Protection 29:1280-1285.]
The accessory glands of male mammals secrete fluid for nourishment of sperm and sexual attraction.
Accessory glands
The male accessory glands are the ampullary gland,
seminal vesicle,
prostate, bulbourethral gland, and
urethral gland.
The products of these glands serve to nourish and activate the Spermatozoon, to clear the urethral tract prior to ejaculation, serve as the vehicle of transport of the spermatozoa in the female tract, and to plug the female tract after placement of spermatozoa to help ensure fertilization. Although the glands are usually described as being branched Tubular gland or branched Alveolar gland, they vary in their organization and in their distribution in different species.
Ampullary glands
Each of these branched tubular glands lined by simple columnar
epithelium is an enlargement of the
vas deferens in its terminal portion. These are typical tubular glands in
, horses and dogs; absent in the cat and poorly developed in boars. The function of the white
Serous fluid is not known.
Seminal vesicles
The secretory endpieces of these glands are lined with simple columnar
epithelium; the main ducts are lined with stratified columnar epithelium. These glands do not occur in
, but are present in some form in horses,
ruminants and swine. Seminal fluid, the product of this gland, serves as a vehicle for the transport of
Spermatozoon.
Prostate gland
Grossly the
prostate gland can be divided into two parts: the body and the disseminate part. Low cuboidal to low columnar
epithelium provides the lining for this compound,
Alveolar gland which consists primarily of serous secretory end pieces. The secretion of this gland is more serous in dogs and more mucous in bulls. It serves to promote the movement of
Spermatozoon and to form a
Mating plug. Additionally, in bulls, the secretion contains high amounts of
fructose and
citric acid.
may be present in the secretory end pieces as well as parts of the duct system. The prostate and Cowper's glands are the only male accessory glands in marsupials.
Bulbourethral glands
The lining of these paired, compound,
Alveolar gland is simple columnar
epithelium. A capsule of dense connective tissue contains some
smooth muscle as well as
skeletal muscle of the bulbospongiosus and urethral muscles. All domestic species have these glands except the dog, and their
mucus secretion serves to clear the
urethra of
urine and to lubricate it and the
vagina. The product may also serve as an energy source for the
Spermatozoon.
Urethral glands
In some species, branched tubular
mucous glands are found along the length of the
urethra, especially dorsal to the lumen of the urethra. The exact function of their product is not clear.
Distribution in insects
The male accessory gland is also prevalent in some species of butterflies and moths. An example is the cotton leafworm, or
Spodoptera litura, in which the males transfer MAG to the females during copulation. This results in a wide range of post-mating behavior in the females, the most noteworthy being the decrease in sexual receptivity in the females. This helps to assure that no other males will mate with that female, allowing her eggs to be fertilized by the current male's own sperm.
See also
-
Male accessory gland infection (MAGI)
-
Female accessory glands: Skene's glands and Bartholin's glands (cf. List of related male and female reproductive organs)
