Seminal vesicle

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Seminal vesicle
Male Anatomy
Prostate with seminal vesicles and seminal ducts, viewed from in front and above.
Latin	vesiculæ seminales
Gray's	subject #260 1246
Artery	Inferior vesical artery, middle rectal artery
Lymph	external iliac lymph nodes, internal iliac lymph nodes
Precursor	Wolffian duct
MeSH	Seminal+Vesicles

The seminal vesicles are a pair of simple tubular glands posteroinferior to the urinary bladder of males.

Contents 1 Anatomy 2 Function 3 Histology 4 Additional images 5 External links

[edit] 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.

[edit] Function

They secrete a significant proportion of the fluid that ultimately becomes semen. About 60% 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.

[edit] 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

[edit] Additional images

Male reproductive system.	Coronal section of pelvis, showing arrangement of fasciæ. Viewed from behind.	Male pelvic organs seen from right side.	Fundus of the bladder with the vesiculæ seminales.
Vesiculæ seminales and ampullæ of ductus deferentes, seen from the front.	Vertical section of bladder, penis, and urethra.	Cross section of seminal vesicle through a microscope.

[edit] External links

• Histology at BU 17501loa - "Male Reproductive System: prostate, seminal vesicle"
• SUNY Labs 44:04-0202 - "The Male Pelvis: The Urinary Bladder"
• SUNY Labs 44:08-0103 - "The Male Pelvis: Structures Located Posterior to the Urinary Bladder"

v • d • e 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, Tunica vasculosa testis) • 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, Stereocilia) • 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