The seminal vesicles are a pair of glands along the back of the bladder base in men and are part of the male genital system. Their main function is to produce a fluid that makes up semen, which is released duringejaculation.
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Anatomy
The seminal vesicles look like two tightly coiled tubular sacs on either side of the back of thebladderbase, or fundus. They are about 2 cm–4 cm (centimeters) long and 1 cm–2 cm in diameter. They usually extend back and out from the base of theprostategland, a bit like rabbit ears.
Structure
At their lower end, each seminal vesicle forms a duct, which joins theductus deferens(which carries sperm cells from the testes). Together, both ducts form the ejaculatory duct, which passes through the prostate gland and joins the prostatic urethra (the portion of the urethra in the prostate gland).
Location
The seminal vesicles are located between the bladder fundusand the rectum.
Anatomical Variations
Occasionally, boys are born with abnormalities of the seminal vesicles. One or both seminal vesicles may be absent (a condition called agenesis). Men withcystic fibrosissometimes have missing seminal vesicles.
Rarely, both seminal vesicles may be on one side.Congenital(at birth) abnormalities of the seminal vesicles are often associated with abnormalities in other parts of the male genitourinary system that makes up the genital and urinary organs, such as the prostate,testes,kidneys, orureters.
Although the seminal vesicles usually extend up and out from the prostate base, they may sometimes turn downward, along the back of the prostate. If this is the case, a doctor performing aprostate exammay mistake the seminal vesicles for a prostate abnormality.This confusion can easily be cleared up with imaging (such as a prostate ultrasound or magnetic resonance imaging, or MRI).
Function
The main function of the seminal vesicles is to produce a fluid that is high in fructose, a sugar that provides nutrients for sperm cells, as well as other proteins, enzymes, and mucus. This fluid is a major component of semen, and it accounts for about 50%–80% of semen volume.
Associated Conditions
Cysts and other malformations of the seminal vesicles are often associated with other problems in the male genitourinary system. For example, people with seminal vesicle cysts at birth are often missing one of their kidneys. Also, the ureters, which usually empty into the bladder, may instead empty into the seminal vesicles or other structures. Congenital abnormalities like these may require surgery for correction.
Other conditions related to the seminal vesicles include the following:
Prostate Cancer
Tests
People with seminal vesicle cysts or infections often have symptoms that are difficult to attribute to a specific organ. They may undergo a general workup looking for signs of infection, such as a physical exam, blood tests, orurinalysis. Men with infertility may undergo analysis of their seminal fluid.
MRI produces the most detailed images of the seminal vesicles. This test is very good at detecting and visualizing seminal vesicle cysts, malformations, and other associated abnormalities of the genitourinary system. MRI is also the best imaging study to determine whether cancer of the prostate, rectum, or bladder has spread to the seminal vesicles.
2 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Bostwick DG. Seminal vesicles. In:Urologic Surgical Pathology. Elsevier; 2020:526-533.e5. https://doi.org/10.1016/B978-0-323-54941-7.00010-4.Clement P, Giuliano F. Anatomy and physiology of genital organs – men. In: Handbook of Clinical Neurology. Vol 130. Elsevier; 2015:19-37. https://doi.org/10.1016/B978-0-444-63247-0.00003-1.Additional ReadingBostwick DG. Seminal vesicles. In:Urologic Surgical Pathology. Elsevier; 2020:526-533.e5. https://doi.org/10.1016/B978-0-323-54941-7.00010-4.Clement P, Giuliano F. Anatomy and physiology of genital organs – men. In: Handbook of Clinical Neurology. Vol 130. Elsevier; 2015:19-37. https://doi.org/10.1016/B978-0-444-63247-0.00003-1.Ernst LM, Ruchelli ED, Ruchelli ED, Huff DS, Huff DS. Seminal vesicle. In: Ernst LM, Ruchelli ED, Huff DS, eds.Color Atlas of Fetal and Neonatal Histology. Springer New York; 2011:157-161. https://doi.org/10.1007/978-1-4614-0019-6_12
2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Bostwick DG. Seminal vesicles. In:Urologic Surgical Pathology. Elsevier; 2020:526-533.e5. https://doi.org/10.1016/B978-0-323-54941-7.00010-4.Clement P, Giuliano F. Anatomy and physiology of genital organs – men. In: Handbook of Clinical Neurology. Vol 130. Elsevier; 2015:19-37. https://doi.org/10.1016/B978-0-444-63247-0.00003-1.Additional ReadingBostwick DG. Seminal vesicles. In:Urologic Surgical Pathology. Elsevier; 2020:526-533.e5. https://doi.org/10.1016/B978-0-323-54941-7.00010-4.Clement P, Giuliano F. Anatomy and physiology of genital organs – men. In: Handbook of Clinical Neurology. Vol 130. Elsevier; 2015:19-37. https://doi.org/10.1016/B978-0-444-63247-0.00003-1.Ernst LM, Ruchelli ED, Ruchelli ED, Huff DS, Huff DS. Seminal vesicle. In: Ernst LM, Ruchelli ED, Huff DS, eds.Color Atlas of Fetal and Neonatal Histology. Springer New York; 2011:157-161. https://doi.org/10.1007/978-1-4614-0019-6_12
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Bostwick DG. Seminal vesicles. In:Urologic Surgical Pathology. Elsevier; 2020:526-533.e5. https://doi.org/10.1016/B978-0-323-54941-7.00010-4.Clement P, Giuliano F. Anatomy and physiology of genital organs – men. In: Handbook of Clinical Neurology. Vol 130. Elsevier; 2015:19-37. https://doi.org/10.1016/B978-0-444-63247-0.00003-1.
Bostwick DG. Seminal vesicles. In:Urologic Surgical Pathology. Elsevier; 2020:526-533.e5. https://doi.org/10.1016/B978-0-323-54941-7.00010-4.
Clement P, Giuliano F. Anatomy and physiology of genital organs – men. In: Handbook of Clinical Neurology. Vol 130. Elsevier; 2015:19-37. https://doi.org/10.1016/B978-0-444-63247-0.00003-1.
Bostwick DG. Seminal vesicles. In:Urologic Surgical Pathology. Elsevier; 2020:526-533.e5. https://doi.org/10.1016/B978-0-323-54941-7.00010-4.Clement P, Giuliano F. Anatomy and physiology of genital organs – men. In: Handbook of Clinical Neurology. Vol 130. Elsevier; 2015:19-37. https://doi.org/10.1016/B978-0-444-63247-0.00003-1.Ernst LM, Ruchelli ED, Ruchelli ED, Huff DS, Huff DS. Seminal vesicle. In: Ernst LM, Ruchelli ED, Huff DS, eds.Color Atlas of Fetal and Neonatal Histology. Springer New York; 2011:157-161. https://doi.org/10.1007/978-1-4614-0019-6_12
Ernst LM, Ruchelli ED, Ruchelli ED, Huff DS, Huff DS. Seminal vesicle. In: Ernst LM, Ruchelli ED, Huff DS, eds.Color Atlas of Fetal and Neonatal Histology. Springer New York; 2011:157-161. https://doi.org/10.1007/978-1-4614-0019-6_12
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