Prostate. structure

The prostate gland , prostata, is an unpaired organ of glandular and smooth muscle tissue; Is located in the lower part of the pelvic cavity below the bladder , between it, the anterior wall of the rectum and the anterior part of the urogenital diaphragm. The gland covers the initial part of the urethra , its prostate part, pars prostatica, as well as the ejaculatory ducts , ductus ejaculatorii.

In its structure, it refers to complex alveolar-tubular glands. The prostate gland has the shape of a chestnut. It distinguishes the downward directed to the urogenital diaphragm, the narrower apex of the prostate, the apex prostatae, and the broad, concave surface directed toward the bladder, the base of the prostate gland, the basis prostatae. The anterior surface, facies anterior, faces the pubic symphysis, and the posterior surface, facies posterior, is directed towards the ampulla of the rectum. In the prostate gland, we can also distinguish rounded lower-lateral surfaces, facies inferolaterales, which are oriented respectively to the right and left sides, to the muscle lifting the anus, m. Levator ani. From the latter departs a small pubic-prostate muscle, m. Puboprostaticus, which is attached to the lower lateral surface of the prostate gland.

In the prostate gland secrete the right and left lobes, lobus dexter et lobus sinister. The lobes are divided on the posterior surface of the gland by an indistinctly expressed groove and isthmus of the prostate, isthmus prostatae (median lobe, lobus medius).

The isthmus of the prostate is called its site, located between the place of entry into its base of the neck of the bladder in front and the right and left ejaculatory ducts - behind; In older people, the isthmus is significantly enlarged and is considered as the median part, lobus medius.

The urethra passes through the anterior section of the gland, perforating its apex, so that most of the gland lies behind the canal, and the smaller part lies ahead. In the direction from the top to the bottom, forward through the base of the gland pass the ejaculatory ducts.

The transverse length of the prostate gland is about 4 cm, the longitudinal length is 3 cm, and the thickness is 2 cm; The mass of the gland on average is 20 g. The magnitude and mass of the gland changes with age: in children, they are small; In the elderly age of iron can reach the size of a chicken egg.

The prostate gland consists of parenchyma, parenchyma, and muscle substance, substantia muscularis. Parenchyma is unevenly distributed throughout the organ; In the direction of the rectum, the glandular parenchyma predominates, while in the direction of the urethra the muscular substance is developed more strongly.

The glandular parenchyma surrounds the prostatic part of the urethra; It consists of 30-50 branching alveolar-tubular prosthetic ducts, ductuli prostatici, lined with epithelium.

The main mass and longer glandular grooves are in the posterior and lateral parts of the gland; Only a small number and, moreover, shorter moves are located in the front; The frontal median part is free of them and contains only a muscular substance.

The gland is surrounded by a capsule of the prostate, capsula prostatica, from which the connective tissue fibers and smooth muscles that make up the stroma of the gland go into the gland. The stroma is located between the ducts, dividing the glandular parenchyma into lobules.

The muscle fibers pass into the gland from the wall of the bladder adjacent to its base. The top of the gland located in the urogenital diaphragm contains transverse striated muscle fibers passing from the latter, which form part of an arbitrary muscle - the urethral sphincter, m. Sphincter urethrae. The mouth of glandular ducts, about 30, opens on the surface of the mucous membrane of the prostatic part of the urethra around the seed hillock and on it itself.

The anterior surface of the gland is formed by the smallest part of the gland located in front of the urethra. From the pubic adhesion and the adjacent section of the tendon arch to the anterior and lateral surfaces of the gland follow the pubic-prostate (pubic-cystic) ligaments, ligg. Puboprostatica (pubovesicalia).

Front to the base of the gland adjoins, fusing with it, the bottom of the bladder. The bodies of the seminal vesicles laterally adjoin the posterior part of the base, medially the ampulla of the vas deferens.

The posterior surface of the gland adjoins the septum separating it from the ampulla of the rectum and forming the posterior wall of its capsule.

The lateral surfaces of the gland, being separated by the wall of the capsule, adjoin the medial margins of both muscles that lift the anus, which, with their contraction, can lift the prostate gland.

Under the capsule of the gland are located the veins that enter the prosthetic venous plexus, into which the deep dorsal vein of the penis drains in front.

The isthmus of the prostate gland, isthmus prostatae, adjacent to the posterior wall of the urethra, carries the prostatic papilla embedded in the canal of the canal, utriculus prostaticus; It has the form of a longitudinally located pocket with a length of up to 1 cm and a width of 1-2 mm.

Innervation: nerves of plexus prostaticus, plexus hypogastricus inferior (sympathetic) and nn. Splanchnici pelvici (parasympathetic).

Blood supply: aa. Rectales media, vesicalis inferior. Venous blood flows down the plexus venosus prostaticus, then through vv. Vesicales inferiores in v. Iliaca interna.

Lymphatic vessels divert lymph to nodi lymphatici iliaci interni.

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• Seed cords.
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• Penis.
• Male urethra.