- Seminal vesicle
Name = Seminal vesicle
Latin = vesiculæ seminales
GraySubject = 260
GrayPage = 1246
Caption = Male Anatomy
Prostatewith seminal vesiclesand seminal ducts, viewed from in front and above.
Width = 300
Inferior vesical artery, middle rectal artery
external iliac lymph nodes, internal iliac lymph nodes
MeshName = Seminal+Vesicles
MeshNumber = A05.360.444.713
The seminal vesicles ("glandulae vesiculosae") are a pair of simple tubular glands posteroinferior to the
urinary bladderof males.
Each seminal gland spreads approximately 5 cm, though the full length of seminal vesicle is approximately 10 cm, but it is curled up inside of the gland's structure. Each gland forms as an outpocketing of the wall of
ampullaof each vas deferens.
excretory duct of seminal glandopens into the vas deferens as it enters the prostate gland.
The seminal vesicles secrete a significant proportion of the fluid that ultimately becomes
semen. About 60% of the seminal fluid in humans originates from the seminal vesicles, but is not expelled in the first ejaculate fractions which are dominated by spermatozoa and zinc rich prostatic fluid. In vitro studies have shown that sperm expelled together with seminal vesicular fluid show poor motility and survival, and the sperm chromatin is less protected. Therefore the exact physiological importance of seminal vesicular fluid is not clear. It has been speculated that it is a developmental rest, still seen among some rodents where the last part of the ejaculate form a spermicidal plug which reduces the chances for sperm from a later arriving male to proceed to the oocyte.
The thick secretions contain
proteins, enzymes, fructose, mucus, vitamin C, flavins, phosphorylcholineand prostaglandins. The high fructose concentrations provide nutrient energy for the spermatozoawhen stored in semen in the laboratory. Spermatozoa ejaculated in the vagina are not likely to have contact with the seminal vesicular fluid but transfer directly from the prostatic fluid into the cervical mucus as the first step on their travel through the female reproductive system. The fluid is expelled under sympathetic contraction of the muscularis muscle coat.
Histologically, the seminal vesicles are notable for their tortuous pathways, diverticula, pseudo-stratified columnar epitheliumand cuboidal cellsalong the basal layer.
The height of these columnar cells, and therefore activity, is dependent upon
testosteronelevels in the blood.
The lumen is large and stores the fluid secretions (but not spermatozoa) between
From inside to out, the layers are:
Mucosa- arranged into convoluted folds, significantly increasing surface area
* Muscular - well-developed layer composed of an inner circular and outer longitudinal layer of
* - "Male Reproductive System: prostate, seminal vesicle"
* - "The Male Pelvis: The Urinary Bladder"
* - "The Male Pelvis: Structures Located Posterior to the Urinary Bladder"
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Look at other dictionaries:
seminal vesicle — n either of a pair of glandular pouches that lie one on either side of the male reproductive tract and that in human males secrete a sugar and protein containing fluid into the ejaculatory duct * * * either of a pair of male accessory sex glands… … Medical dictionary
seminal vesicle — Anat. either of two small saclike glands, located on each side of the bladder in males, that add nutrient fluid to semen during ejaculation. [1885 90] * * * ▪ anatomy either of two elongated saclike glands that secrete their fluid contents… … Universalium
seminal vesicle — the enlarged lower end of the genital duct which is secretory in nature and completes the formation of the spermatophores and stores them. The so called seminal vesicles of teleosts (Blennioidea, Gobioidea) are misnamed and do not store sperm;… … Dictionary of ichthyology
seminal vesicle — n. seminal gland, one of the paired glands that produces seminal liquied … English contemporary dictionary
seminal vesicle — 1. A male sac , tube or pouch like structure in which spermatozoa is stored before being discharged; seminal reservoir; vesicula seminalis. 2. (ANNELIDA) A pouch usually formed in a posterior septum of a testicular segment where the latter stages … Dictionary of invertebrate zoology
seminal vesicle — either of a pair of male accessory sex glands that open into the vas deferens before it joins the urethra. The seminal vesicles secrete most of the liquid component of semen … The new mediacal dictionary
seminal vesicle — noun Date: circa 1890 either of a pair of glandular pouches that lie one on either side of the male reproductive tract and in the human male secrete a sugar and protein containing fluid into the ejaculatory duct … New Collegiate Dictionary
seminal vesicle — noun /ˈsɛmɪnəlˌvɛsɪkl/ One of two simple tubular glands located behind the male urinary bladder, responsible for the production of about sixty percent of the fluid that ultimately becomes semen … Wiktionary
seminal vesicle — Organ which stores sperm of male [Holdich and Jones, 1983]. Sac in male independent of testes for storage of spermatozoa (e.g., some anostracans, Chirocephalidae). (Syn. vesicula seminalis) [Moore and McCormick, 1969]. Sac in male, independent of … Crustacea glossary
seminal vesicle — sem′inal ves′icle n. anat. either of two small saclike glands, located on each side of the bladder in males, that add nutrient fluid to semen during ejaculation • Etymology: 1885–90 … From formal English to slang