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The seminal vesicles are a pair of simple tubular glands posteroinferior to the urinary bladder of males.
Anatomy
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 ampulla of each vas deferens.
The excretory duct of seminal gland opens into the vas deferens as it enters the prostate gland.
Function
They secrete a significant proportion of the fluid that ultimately becomes semen. About 70% of the seminal fluid in humans originates from the seminal vesicles.
The thick secretions contain proteins, enzymes, fructose, mucus, vitamin C, flavins, phosphorylcholine and prostaglandins. The high fructose concentrations provide nutrient energy for the spermatozoa as they travel through the female reproductive system. The fluid is expelled under sympathetic contraction of the muscularis muscle coat.
Histology
Histologically, the seminal vesicles are notable for their tortuous pathways, diverticula, pseudo-stratified columnar epithelium and cuboidal cells along the basal layer.
The height of these columnar cells, and therefore activity, is dependent upon testosterone levels in the blood.
The lumen is large and stores the fluid secretions (but not spermatozoa) between ejaculations.
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 smooth muscle
- Connective tissue
Additional images
Illu repdt male.jpg
Male reproductive system.
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Gray402.png
Coronal section of pelvis, showing arrangement of fasciæ. Viewed from behind.
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Gray1136.png
Male pelvic organs seen from right side.
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Gray1152.png
Fundus of the bladder with the vesiculæ seminales.
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Gray1153.png
Vesiculæ seminales and ampullæ of ductus deferentes, seen from the front.
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Gray1156.png
Vertical section of bladder, penis, and urethra.
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Seminal vesicle.JPG
Cross section of seminal vesicle through a microscope.
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External links
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Male reproductive system |
| Scrotum |
layers (skin, Dartos, External spermatic fascia, Cremaster/Cremasteric fascia, Internal spermatic fascia) • Perineal raphe • Spermatic cord |
| Testes |
layers (Tunica vaginalis, Tunica albuginea) • Appendix • Mediastinum • Lobules • Septa • Leydig cell • Sertoli cell • Blood-testis barrier |
| Spermatogenesis |
Spermatogonium • Spermatocytogenesis • Spermatocyte • Spermatidogenesis • Spermatid • Spermiogenesis • Spermatozoon |
| seminal tract |
Seminiferous tubules (Tubuli seminiferi recti, Rete testis, Efferent ducts) • Epididymis (Appendix) • Vas deferens (Ampulla) • Ejaculatory duct |
| urinary tract |
Internal urethral orifice • Urethra (Prostatic, Intermediate, Spongy, Navicular fossa) • External urethral orifice |
| accessory glands |
Seminal vesicles (Excretory duct of seminal gland) • Prostate (Urethral crest/Seminal colliculus/Prostatic utricle/Ejaculatory duct, Prostatic sinus/Prostatic ducts) • Bulbourethral glands |
| Penis |
root (Crus, Bulb, Fundiform ligament, Suspensory ligament) • body (Corpus cavernosum, Corpus spongiosum) • glans (Foreskin, Frenulum, Corona) • fascia (superficial/subcutaneous, deep/Buck's) • Tunica albuginea - Septum of the penis |
cs:Semenný váček
da:Sædblære de:Samenblase dv:މަނި ގޮށް es:Vesícula seminal fr:Vésicules séminales id:Vesikula seminalis it:Vescicola seminale la:Vesicula seminalis lt:Sėklinės pūslelės nl:Zaadblaas ja:精嚢 pl:Pęcherzyk nasienny pt:Vesícula seminal ru:Семенные пузырьки simple:Seminal vesicle sk:Semenný mechúrik fi:Rakkularauhanen sv:Sädesblåsa te:శుక్రకోశం
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