Vesicle gland

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Location of the seminal vesicle

The seminal vesicles , even outdated seminal vesicle or seminal vesicle , ( parotid vesiculosa , seminal vesicle , in mammals as seminal vesicle gland, parotid vesicular called) is a paired-scale in the male accessory sex gland that about her Ausführgang, the ductus excretorius , in each case together with the equilateral vas deferens ( Ductus deferens) opens into the urethra in the area of ​​the seed mound . Since in the vesicula seminalis - contrary to previous assumptions - there is no storage of sperm, the term "vesicle gland" is preferable.

Human anatomy

The vesicle gland is paired in men and is located in the pelvic area near the prostate . It is about five centimeters long and consists of a single 15 centimeter long, multi-winding passage with a wide lumen . The surface epithelium is prismatic in one or two layers ; it flattens out with age. It secretes its secretion mainly via exocytosis , apocrine secretion can also occur. The surface relief has a complicated structure; the partitions between two gland sections can be connected to one another via epithelial bridges.

The outer wall contains smooth muscle cells and elastic fibers. This structure enables the secretion to be released quickly during ejaculation .

function

The vesicle gland produces ( depending on testosterone ) an alkaline secretion that is rich in fructose and makes up around 70% of the liquid part of the sperm . The fructose serves the sperm as an energy supplier in the seminal fluid, so that they can reach the female egg cell as quickly as possible and fertilize it during sexual intercourse .

Comparative anatomy

Most other mammals also have a vesicle gland, only in predators it is not developed. However, the bladder character is not pronounced in all species. In the case of even-toed ungulates , it is z. B. a compact gland of bumpy, coarse consistency.

Importance in zoology

In the animal kingdom, containers for storing sperm are also known as “seminal vesicles”. The Latin term for such a storage bag is Receptaculum seminis . Females of ants or bees, for example, store the sperm in it after copulation , only to use them shortly before laying eggs to determine the sex of the new individual.

On the other hand, males (such as dragonflies ) such storage bags serve to give off plenty of sperm during copulation.

literature

  • Uwe Gille: urinary and sexual system, urogenital apparatus . In: Franz-Viktor Salomon et al. (Ed.): Anatomy for veterinary medicine . 2nd ext. Edition Enke, Stuttgart 2008, ISBN 978-3-8304-1075-1 , pp. 389-403 .
  • Ulrich Welsch: Textbook Histology . Elsevier Urban & Fischer, Munich 2010, ISBN 978-3-437-44431-9 , pp. 417 .
  • Gerhard Aumüller u. a .: Dual series anatomy . Thieme, Stuttgart 2010, ISBN 978-3-13-136042-7 , p. 749 f .