What are Seminal Vesicles?

(Image courtesy of Henry Vandyke Carter, Public domain, via Wikimedia Commons)

​The seminal vesicles or seminal glands are two tube-like glands located between the bladder and the rectum, behind the prostate. Each vesicle consists of a 3-5 cm coiled tube containing multiple pouches.

The seminal vesicles contribute between 50-80% of the components found in semen, specifically the late ejaculate fluids that support the successful transfer of sperm out of the body. The fluid produced by the seminal vesicles is alkaline, meaning it has a high pH, which provides protection for the spermatozoa in the acidic environment of the female vagina. Seminal vesicles also contribute fructose to semen, which is used as an energy source by spermatozoa, as well as other proteins and enzymes.

A critical component of semen that is provided by the seminal vesicles is semenogelin. This protein creates a gel-like barrier around ejaculated spermatozoa to ensure that capacitation does not occur prematurely.

Each seminal vesicle combines with the vas deferens at the ejaculatory duct, which carries semen through the prostate and into the urethra prior to exiting the body during ejaculation.

Nuts & Bolts: Seminal Vesicles

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Key terms:

Alkaline - bases that are soluble in water with a pH greater than 7.0.

Ejaculation - the action of ejecting semen from the body.

Enzyme - a substance produced by a living organism which acts as a catalyst to bring about a specific biochemical reaction.

Protein - essential nutrients for the human body that are one of the building blocks of body tissue and can also serve as a fuel source.

Semen - the male reproductive fluid, containing spermatozoa in suspension

​Spermatozoa - the mature motile male sex cells of an animal, by which the ovum is fertilized, typically having a compact head and one or more long flagella for swimming.

For additional terminology related to male contraception and the male reproductive system, please visit our glossary:

Glossary

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Sources/References:

Gonzales GF. Function of Seminal Vesicles and Their Role on Male Fertility. Asian J Androl 2001 Dec; 3:251-258.

Nieschlag, E., H. M. Behre, and S. Nieschlag. 2010. Andrology: male reproductive health and dysfunction. Springer EBooks. Berlin: Springer. http://site.ebrary.com/id/10361868.

McKay AC, Odeluga N, Jiang J, et al. Anatomy, Abdomen and Pelvis, Seminal Vesicle. [Updated 2020 Jul 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK499854/

Michael H. Ross; Wojciech Pawlina (2010). "Male Reproductive System". Histology: A Text and Atlas, with Correlated Cell and Molecular Biology (6th ed.). p. 828.

Mortimer D. 1994. Practical laboratory andrology. Oxford University Press. New York.

​Standring, Susan, ed. (2016). "Seminal vesicles". Gray's anatomy : the anatomical basis of clinical practice(41st ed.). Philadelphia. pp. 1279–1280.

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