Zonal structure of the prostate gland. Why is it important to know the anatomy of the prostate gland? Zonal division of prostate tissue

And the anterior part of the genitourinary diaphragm. The gland covers the initial part, its prostatic part, pars prostatica, as well as the ductus ejaculatorii.

In terms of its structure, it belongs to the complex alveolar-tubular glands. The prostate gland is shaped like a chestnut. It distinguishes between a narrower apex of the prostate gland, directed downwards towards the urogenital diaphragm, apex prostatae, and a wide base of the prostate gland, with a concave surface, directed towards the bladder, basis prostatae. The anterior surface, facies anterior, faces the pubic symphysis, and the posterior surface, facies posterior, faces the ampulla of the rectum. In the prostate gland, one can also distinguish rounded inferolateral surfaces, facies inferolaterales, which face the right and left sides, respectively, to the levator ani muscle, m. levator ani. From the latter comes a small puboprostatic muscle, m. puboprostaticus, which is attached to the inferolateral surface of the prostate gland.

IN prostate gland The right and left lobes are distinguished, lobus dexter et lobus sinister. The lobes are separated along the posterior surface of the gland by a vaguely pronounced groove and isthmus of the prostate gland, isthmus prostatae (middle lobe, lobus medius).

Isthmus prostate gland is called its section located between the place where the bladder neck enters its base in front and the right and left ejaculatory ducts in the back; in older people, the isthmus is significantly enlarged and is considered as the middle lobe, lobus medius.

The urethra passes through the anterior inferior part of the gland, piercing its apex, so that most of the gland lies behind the canal, and the smaller part lies in front. The ejaculatory ducts pass through the base of the gland from top to back down to front.

Transverse prostate length about 4 cm, longitudinal - 3 cm, and thickness 2 cm; the weight of the gland is on average 20 g. The size and weight of the gland change with age: in children they are small; in old age, iron can reach the size of a chicken egg.

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

Glandular parenchyma surrounds the prostatic part of the urethra; it consists of 30-50 branching alveolar-tubular prostatic ducts, ductuli prostatici, lined with epithelium.

The main mass and longer glandular ducts are located in the posterior and lateral parts of the gland; only a small number and, moreover, shorter strokes are located in front; the most anterior median area is free from them and contains only muscle substance.

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

Muscle fibers pass into the gland from the wall of the bladder adjacent to its base. The apex of the gland, located in the genitourinary diaphragm, contains striated muscle fibers passing from the latter, which form part of the voluntary muscle - the sphincter of the urethra, m. sphincter urethrae. The orifices of the glandular ducts, about 30, open on the surface of the mucous membrane of the prostatic part of the urethra around the seminal mound and on it itself.

Anterior surface of the gland formed by its smallest section, located in front of the urethra. From the pubic fusion and the adjacent section of the tendinous arch to the anterior and lateral surfaces of the gland follow the puboprostatic (pubovesical) ligaments, ligg. puboprostatica (pubovesicalia).

In front, the bottom of the bladder is adjacent to the base of the gland, fused with it. The bodies of the seminal vesicles adjoin the posterior part of the base laterally, and the ampoules of the vas deferens medially.

The posterior surface of the gland is adjacent to the septum that separates it from the ampulla of the rectum and forms the posterior wall of its capsule.

The inferolateral surfaces of the gland, being separated by the wall of the capsule, are adjacent to the medial edges of both levator ani muscles, which, when contracted, can elevate the prostate gland.

Under the capsule of the gland there are veins that enter the prostatic venous plexus, into which the deep dorsal vein of the penis flows in front.

The isthmus of the prostate gland, isthmus prostatae, adjacent to the posterior wall of the urethra, carries the prostatic uterus, utriculus prostaticus, embedded in the seminiferous mound of the canal; it looks like a longitudinally located pocket up to 1 cm long and 1-2 mm wide.

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

Blood supply: ah. rectales media, vesicalis inferior. Venous blood flows through the plexus venosus prostaticus, then through the vv. vesicales inferiores in v. iliaca interna.

Lymphatic vessels drain lymph to the nodi lymphatici iliaci interni.

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Chapter 16

RADIATION ANATOMY OF THE PROSTATE

IN MEN

NORMAL AND TOPOGRAPHIC ANATOMY OF THE PROSTATE

The prostate gland is located in the lower anterior third of the pelvis under the bladder between the symphysis pubis and the rectum. It has the shape of a truncated cone. The anterior, somewhat concave surface of the gland faces the symphysis, and the posterior, slightly convex surface faces the rectum. A vertical groove runs along the middle of the posterior surface of the gland, dividing it into the right and left lobes, although anatomically and functionally it is a single organ. The base of the gland faces the bottom of the bladder, the apex is adjacent to the urogenital diaphragm. The posterior surface of the prostate gland borders the rectum.

The urethra passes through the prostate gland from its base to the apex, located in the median plane, closer to the anterior surface of the prostate. The vas deferens enter the gland at the base, are directed through the thickness of the prostate downwards, medially and anteriorly, opening into the lumen of the urethra (Fig. 16.1).

The prostate gland is a glandular-muscular organ. Its function as a gland is to secrete secretions into the sperm; contraction of the sphincter prevents urine from entering the urethra during ejaculation. A powerful muscular component covers the prostatic urethra. The following fibromuscular zones are distinguished:

1) the anterior fibromuscular zone, covering the anterior part of the prostate gland and being a continuation of the detrusor;

2) longitudinal smooth muscle fibers of the urethra;

3) preprostatic and postprostatic sphincters.

The glandular tissue of the organ is heterogeneous and consists of three types of epithelial cells, differing from each other in histogenesis and ability to metaplasia. Each type of epithelial cell is concentrated in separate zones located in certain areas of the prostate gland. Depending on their location in relation to the vas deferens and the lumen of the urethra, three glandular zones are distinguished (Fig. 16.2).

Rice. 16.1. Anatomy of the male pelvis. Sagittal section.

1 - bladder; 2 - seminal vesicles; 3 - preprostatic sphincter; 4 - vas deferens; 5 - prostate capsule; 6 - rectum; 7 - prostatic urethra; 8 - genitourinary diaphragm; 9 - bulbourethral glands; 10 - membranous urethra; 11 - prostate gland; 12 - anterior fibromascular zone; 13 - periprostatic tissue; 14 - base of the prostate gland; 15 - neck of the bladder; 16 - pubic symphysis; 17 - wall of the bladder; 18 - bottom of the bladder; 19 - mouth of the ureter.

Epithelial (glandular) zones of the prostate gland

1. Central zones located along the urethra. In longitudinal sections, they have the appearance of a cone, tapering from the base of the prostate gland to its apex. On cross sections, each of these zones looks like a truncated oval with a depression in the medial part. The area of ​​these depressions contains the lumens of the vas deferens. The largest number of cells in the central zone is located at the posterior surface of the gland. In the area of ​​the mouth of the vas deferens, which open into the lumen of the urethra, the central zones end.

2. Peripheral zones located lateral to the central one. They occupy the main part of the prostate gland, spreading to the tip of the organ. Displayed as crescent moons

in the lateral parts of the gland. In most cases, prostate cancer develops due to metaplasia of cells located in the peripheral zones.

Rice. 16.2. Scheme of the zonal structure of the prostate gland (cross section).

1 - central zone; 2 - peripheral zone; 3 - intermediate zone; 4 - prostatic part of the urethra; 5 - vas deferens.

3. Intermediate zone localized near the lumen of the urethra. Epithelial cells of the intermediate zones make up only about 5% of the entire glandular tissue of the organ and are the most likely source of the development of prostate adenomas.

The part of the prostate gland between the vas deferens and the posterior surface of the urethra constitutes the middle lobe.

The vascular anatomy of the prostate gland is completely consistent with its zonal structure. The blood supply is carried out by the prostatic arteries, which are a continuation of the inferior cystic arteries. The urethral arteries extend from the prostatic arteries to the inner part of the gland, and the capsular arteries to the outer part. The venous vessels of the prostate gland accompany the arteries of the same name, and leaving the parenchyma, they form plexuses in the surrounding paraprostatic tissue.

ULTRASONIC ANATOMY PROSTATE GLAND

Ultrasound of the prostate gland includes two complementary methods: transabdominal and transrectal ultrasound scanning.

An echographically unchanged prostate gland with longitudinal transabdominal scanning has the appearance of a cone-shaped formation with clear contours located behind the bladder. The gland capsule is revealed as a hyperechoic structure 1-2 mm thick. The prostate tissue has a fairly uniform, finely punctuated structure. When echography performed in a strictly sagittal plane, the neck of the bladder is quite clearly visualized. In a number of patients, the anterior fibromuscular zone and prostatic urethra are identified as hypoechoic zones. When the sensor deviates to the sides from the midline, the lobes of the prostate gland and seminal vesicles are displayed. Seminal vesicles are defined as paired hypoechoic formations located along the posterolateral surfaces of the base of the gland (Fig. 16.3). On transverse echograms, the prostate gland appears as a round or ovoid formation (Fig. 16.4). Anterior to it is the bladder, and posteriorly the rectum. Normally, according to N.S. Ignashin, the supero-inferior size (length) of the prostate gland is 24-41 mm, the anteroposterior size is 16-23 mm, the transverse size is 27-43 mm. A more accurate indicator is the volume of the prostate gland, which normally should not exceed 20 cm 3 . With age, there is a gradual increase in the size of the prostate gland.

Rice. 16.3. Ultrasound of the prostate gland

Longitudinal transabdominal

scanning.

1 - bladder; 2 - prostate gland; 3 - seminal vesicle.

Rice. 16.4. Ultrasound of the prostate gland, transverse scanning.

1 - bladder; 2 - prostate gland.

Transrectal ultrasound is a highly informative method for assessing the structure, size and shape of the gland. On midsagittal sections, the unchanged prostate gland has

the shape of an elongated cone, tapering from its base to the apex, slightly deviating anteriorly. The parenchyma of the gland has a fine granular structure. On echograms it is possible to distinguish between central and peripheral zones. The peripheral zone is characterized by medium echogenicity and has a homogeneous structure. The central zone is less echogenic and is located along the prostatic urethra. Has a cellular structure. The transition zone is not visualized during echography. In elderly patients, there may be no differentiation between the central and peripheral zones. In these cases, it is necessary to focus on the anatomical criteria for the localization of epithelial zones. The size and shape of the right and left lobes are normally approximately the same.

The prostatic urethra has the appearance of a hypoechoic linear structure extending from the base to the apex of the prostate gland. More clearly than with transabdominal ultrasound, the hypoechoic fibromuscular zone, localized in the anterior parts of the prostate gland, is also determined.

The capsule of the gland is clearly visualized in the form of an echo-positive structure with clear contours about 1 mm thick, as well as the neck of the bladder, well delimited from the base of the prostate gland. Between the posterior surface of the prostate gland and the anterior wall of the rectum, a hypoechoic space 4-5 mm wide is detected - periprostatic tissue. The seminal vesicles have the appearance of hypoechoic symmetrical oval structures with clear contours. The size of the seminal vesicles is highly variable. Their transverse diameter ranges from 6 to 10 mm in patients under 40-50 years of age and from 8 to 12 mm in patients over 50 years of age. The diameter of the seminal vesicles after ejaculation is almost halved.

The use of color (CDC) and power Doppler mapping (EDC) makes it possible to obtain an idea of ​​the vascular anatomy of the prostate gland.

A study in the Color Doppler mode allows normal visualization and assessment of the course and direction of the prostatic and urethral arteries in all patients. Capsular arteries, due to the physical characteristics of this method, do not receive their image during color circulation. In EDC mode, it is possible to trace the course of all intraprostatic vessels.

During longitudinal scanning, arteries (sometimes paired) accompanying the urethra and vas deferens are identified in the thickness of the prostate gland. Numerous veins, which usually accompany large arterial trunks, are clearly displayed. Directly in the parenchyma of the peripheral and central zones, only individual signals from the arterial blood flow are detected. It is usually not possible to visualize vessels in the anterior fibromuscular zone due to their smaller diameter and greater distance from the sensor.

With Doppler mapping, the vessels of the capsular arterial plexus are identified more clearly along the posterolateral surfaces of the gland. When scanning in the transverse plane, the capsular arteries, symmetrically penetrating the peripheral part of the prostate gland and moving towards each other, are radially distributed in it, creating a rectilinear fan-shaped vascular pattern.

The most complete picture of the vascular pattern and vascularization of the prostate gland can be obtained using three-dimensional volumetric reconstruction, which allows a three-dimensional representation of the course and relative position of the vessels and parenchyma of the gland.

To assess arterial blood flow in the pulsed Doppler scanning mode, the maximum systolic velocity, resistance (R^) and pulsatility (P) indices are calculated. The density of the vascular network is also assessed. The prostatic artery has a high, narrow, sharp systolic peak and a low-amplitude, flat diastolic peak. The values ​​of peak blood flow velocities in the prostatic artery average 20.4 cm/s (from 16.6 cm/s to 24.5 cm/s), the resistance index is 0.92 (from 0.85 to 1.00). Dopplerograms of the urethral and capsular arteries are comparable to each other, have a wide, medium-amplitude, sharp systolic peak and flat diastolic peak. The values ​​of peak blood flow velocities and resistance index in the urethral and capsular arteries are on average 8.19+1.2 cm/s and 0.58±0.09 cm/s, respectively. Dopplerograms of the prostate veins are a medium-amplitude straight line. The average velocity in the veins of the prostate gland varies from 4 cm/s to 27 cm/s, averaging 7.9 cm/s.

CT ANATOMY OF THE PROSTATE GLAND

On CT, the unchanged prostate gland is displayed as the formation of a homogeneous structure with a densitometric density of 30-65 HU (Fig. 16.5). Located on sections below the exit of the urethra from the bladder. The seminal vesicles are located behind the posterior wall of the bladder and are surrounded by fatty tissue. They are located at an angle to each other. They have the form of symmetrical paired oblong formations up to 50-60 mm long, 10-20 mm wide, which pass into the vas deferens. Separated from the rectum by the peritoneoperineal fascia. Next to the seminal vesicles are the ureters, which are intersected in the medial direction by the vas deferens. CT scan of small

Rice. 16.5. CT scan of the prostate gland.

1 - bladder; 2 - head of the femur; 3 - ampulla of the rectum; 4 - internal obturator muscle; 5 - pubic bone; 6 - prostate gland; 7 - gluteus maximus muscle.

pelvis is highly informative in determining anatomical and topographic relationships, but is not very informative in identifying structural changes in the prostate gland.

CT does not differentiate epithelial and fibromuscular zones due to their identical X-ray density. It is also impossible to visualize the capsule of the gland and the prostatic urethra.

ANATOMY OF THE PROSTATE ABOUT MRI IMAGING

MRT combines the advantages of ultrasound and CT: the method is highly sensitive for detecting structural changes in the prostate gland and provides complete information about the condition of surrounding tissues and organs. When using devices with high magnetic field strength, it is possible to visualize various anatomical structures: fibromuscular zone, central, transitional and peripheral zones. The seminal vesicles, prostatic urethra, seminal tubercle and gland capsule are well differentiated. The zonal structure of the prostate gland is most clearly displayed on T2-VI. The peripheral zone has a high signal intensity, the transitional and fibromuscular zone has a low signal, the central zone is represented by signals of medium intensity (Fig. 16.6-16.8).

Rice. 16.6. MRI of the prostate, T2-VI.

a - coronal plane, b - sagittal plane. Here and in Fig. 16.7, 16.8:

1 - gland capsule; 2 - urethra; 3 - anterior fibromuscular zones; 4 - seminal vesicles; 5 - peripheral zone.

Rice. 16.7. MRI of normal prostate gland. T2-VI. Axial plane.

Rice. 16.8. MRI of normal prostate gland. T2-VI.

Literature

1. Gromov A.I. Ultrasound examination of the prostate gland.- M.: Bioinforser-vis, 1999.- P. 3-15.

2. Zubarev A.V., Gazhonova V.E. Diagnostic ultrasound. Diagnostic ultrasound. Uronephrology.- M.: Firm Strom LLC, 2002.- P. 131-142.

3. Ternovoy S.K., Sinitsyn V.E. Computed tomography and magnetic resonance imaging of the abdominal cavity. Educational atlas. CD-disk. - M.: Vidar-M, 2000.

4. Tsyb A.F., Grishin G.I., Nestaiko G.V. Ultrasound tomography and targeted biopsy in the diagnosis of pelvic tumors. - M.: Kabour, 1994. - P. 31-39.

5. Arning R.G. et al. Technical aspects of transrectal ultrasound of prostate.- Nigmegen Netherland, 1996.- P. 71.

6. HigginsNE., Hricak H., Helms C.A. Magnetic resonance imaging of the body. 2nd ed. - New York: Raven Press, 1992. - P. 939-935.

7. Kaye K. W., Richter L. Ultrasonographic anatomy of normal prostate gland: reconstruction of computer graphics // Urology- 1990.- V. 35.- P. 12-17.

8. McNeal. The prostate gland: morphology and pathology // Monogr. Urol.- 1983, 4:3.- C 159.

9. Robett R., John R. Clinical Magnetic Resonance Imagine. - Philadelphia, 1990. - P. 952-980.

10. Stark D.D., Bradley W.G. Magnetic resonance imaging. 2nd ed.-St. Louis: Mosby-Year Book, 1992.- P. 2058-2078.

11. Wegener O.H. Whole Body Computed Tomography - Boston, 1992. - P. 425-430.

Not everyone knows what it is and what its anatomy is. The prostate is located in the pelvis in men; its main function is the production of secretory fluid necessary for the body to ensure sperm activity. When the function of the gland is disrupted and inflammatory processes or neoplasms appear in it, serious problems arise with urine output and potency.

Knowledge about the structure of the prostate and its functioning will help maintain the health of the organ

The most common prostate pathologies in older men are cancer and hyperplasia. Prostatitis occurs in younger patients and often occurs with complications. Every man needs to know where the prostate is located and how it works, as well as the symptoms of its diseases.

How does the gland work?

The male gland is located in the central part of the pelvis between the bladder, rectum and pubic symphysis.

The anatomy of the prostate is such that it is connected to part of the urethral canal, therefore, with the development of inflammation in the tissues of the prostate gland, problems with urination may occur - pain, weakening of the stream and difficult outflow of urine.

An enlarged prostate leads to disruption of urination and reproductive functions due to compression of the bladder and genital organs

As a result of an increase in the volume of the prostate in men, with prostatitis, adenoma or cancer, compression of the vas deferens occurs, which causes erectile dysfunction and decreased sexual activity.

The gland is attached to the pubic bone by muscle fibers. The space located next to the prostate and pubic area contains veins and fat. Thanks to a network of arteries that have branches from the vessels of the rectum and bladder, the gland is supplied with blood, the outflow of which from its tissues is ensured by the plexus of Santorini.

The anatomy of the prostate gland allows palpation using the rectal method, which helps to determine changes in the organ that occur due to inflammation, hyperplasia and malignant pathology. As a rule, the urologist performs palpation during the initial examination.

The gland is light in weight (about 20 grams) and looks like a chestnut. are about 2*4 cm. In older men, this organ becomes smaller as a result of involution. When hyperplasia or malignant neoplasm appears, the volume of the prostate can increase significantly.

The gland has a groove running along its surface and dividing the organ into several parts. The lobes of the prostate are usually distinguished into left, right and isthmus, called the middle lobe. Inside, the prostate gland consists of alveoli and tubes through which secretory fluid flows.

The anatomical acinus is a structural unit of the prostate, which contains 30–50 such parts.

The parenchyma of the gland is also divided into parts, the central of which is located next to the bladder.

Internal structure of the prostate

Main functions

The structure of the prostate and its location make it possible to call it the “second heart” of a man. Despite the fact that the gland is very small, it plays a vital role in the male body. This body performs the following functions:

1. Secretory - the production of a special fluid that dilutes sperm and maintains its quality necessary for fertilization.
2. The motor gland, thanks to which seminal fluid is released during ejaculation, at the same moment the gland prevents urine from entering the urethral canal.
3. Protective, which helps prevent the penetration of bacteria from the urinary tract into other pelvic organs.

Microscopy of prostate secretion is necessary to assess its functional state

Prostatic fluid contains many biological components: a specific antigen protein, sodium citrate, enzymes, lysozyme. The secretion can stagnate in the gland due to a sedentary lifestyle and irregular sexual contacts. This phenomenon leads to the development of inflammatory processes that cause serious consequences.

Prostate diseases

Most often, urologists diagnose inflammation of the gland. Some men suffer from congestive prostatitis, in which microcirculation in the tissues is disrupted. Against the background of the accumulation of secretions and the entry of bacteria from the urinary tract, an infectious disease develops, accompanied by hyperthermia and intoxication. In the case of prolonged prostatitis and in the absence of therapy, the appearance of cystic formations and purulent foci, areas of fibrosis is possible.

Sclerotic tissue damage leads to decreased potency, deterioration of semen quality and infertility.

Frequent inflammatory processes in the prostate can cause male infertility

Typically, symptoms of inflammatory disease of the gland are expressed in pain in the groin, rectal area, discomfort during sexual intercourse, and problems with erection. The same signs also occur with the development of bacterial prostatitis, which can be caused by infections such as chlamydia and trichomoniasis.

In men over 50 years of age, the risk of prostate hyperplasia increases significantly. This is due to the development of hormonal imbalance, diseases of the endocrine and reproductive systems. Prostate adenoma is diagnosed using ultrasound, laboratory tests, and palpation. This disease is not considered malignant, but carries the risk of developing acute urinary retention. This condition is accompanied by severe intoxication, which is characterized by vomiting, dizziness, severe headaches, weight loss, loss of appetite, yellowness of the skin and mucous membranes. Symptoms arise due to the enlarged prostate squeezing the urinary tract. If such complications develop, emergency hospitalization of the man is required.

Acute urinary retention is a life-threatening condition that requires urgent medical attention.

There are also frequent cases of the development of malignant prostate disease, which is life-threatening not only due to compression of nearby organs by the enlarged gland, but also due to metastases to other organs and tissues.

Depending on the stage and symptoms accompanying prostate cancer, doctors decide on the treatment method.

Today, pathological prostate tissue cells are removed using surgery, radiation or chemotherapy. The stage of the disease is of great importance. If a tumor is detected at the beginning of its development, the chances of restoring health are quite high. After treatment, the patient should regularly visit the urologist. An indicator of the appearance of disorders in the gland is prostatic antigen. If changes in this organ are suspected, a man should regularly donate blood for PSA.

PSA level testing helps prevent prostate tumor recurrence

Preventive measures

In order to avoid the appearance of disorders in the prostate and the development of its dysfunction, men must adhere to some rules, which are as follows:

• You should exercise regularly and take walks;
• avoid hypothermia;
• avoid prolonged sexual intercourse;
• do not delay the ejaculation process;
• Healthy food;
• have sex with a regular partner;
• eliminate alcohol and nicotine;
• consume enough water.

Staying hydrated benefits the entire body

An important preventive measure is an annual visit to the urologist.

If a man has previously been diagnosed with chronic prostatitis, he should be examined more often. If the disease worsens, you should definitely consult a doctor. You should not choose medications and other treatment methods on your own. It is important to remember that untreated chronic gland disease can lead to impotence and infertility.

About the structure of the prostate gland and its functions, see the video below:

The prostate gland is a single glandular-muscular organ of the male reproductive system, located directly below the bladder near the anterior wall of the rectum. The main task of the prostate gland is to produce secretion, which, pouring into the prostatic part of the urethral canal, mixes with the secretion of the seminal vesicles and sperm. At the same time, the sperm acquires the required volume, viscosity and PH level.

Thus, the prostate performs a whole bunch of functions at once:

According to the principle of operation, the prostate is a hormonally dependent organ, which is under the direct control of the internal neurohormonal system “hypothalamus-pituitary-testes”. In particular, a direct dependence of the organ’s functioning on the level of plasma testosterone, as well as its active form – degdrotestosterone, was revealed.

Scheme of the action of the neurohormonal system on the reproductive system

In the hypothalamus, the body produces gonadotropin (GT), a hormone devoid of sex specification. ADT causes the pituitary gland in the brain to produce LH (luteinizing hormone) and FSH (follicle stimulating hormone). LH directly acts on the genitals, activating the production of testosterone by the cells of the testes. The vast majority of the produced male hormone is in the body bound to proteins, and only 2% is in an unbound form.

The prostate is the main target organ for the effects of free testosterone. Penetrating into its cells with the bloodstream, the hormone, with the help of 5-alpha reductase, is reconstructed into active dehydrotestosterone, which, in turn, triggers the synthetic activity of the organ itself. The higher the level of dehydrotestosterone, the higher the level of synthetic activity of the prostate gland, which leads to the gradual proliferation of its glandular part.

Organ structure

In an adult man, after the end of puberty, the prostate weighs on average 20 g and has a round shape (3 by 4 cm) with a complex interweaving of internal systems. It covers the initial section of the urethral canal and the ejaculatory ducts, which are involved in the structural and functional network of the gland.

The wall of the urethra passing through the prostate has 3 layers: mucous, submucosal and muscular. The serous membrane in this area is absent, replaced by the connective tissue capsule of the prostate itself. In the area of ​​the proximal urethra, just behind the internal opening of the urethra, there is a sphincter.

Anatomically, the prostate has an apex, as well as right and left lobes, separated by a groove and connected by an isthmus. Externally, this entire structure is “clad” with a serous membrane.

Zonal division of prostate tissue

At the moment, the so-called zonal system of the structure of the prostate gland, developed by J.E. McNeal in 1981, has become widespread, according to which the organ has 4 glandular zones (central, peripheral and 2 transitional) and 4 fibromuscular layer (anterior fibromuscular stroma and 3 components of the circular muscular layer surrounding the urethral duct). The main landmark for this division is the urethra.

The anterior fibromuscular stroma and the circulatory layer are formed by muscle and connective tissue elements. They are devoid of glandular cells and occupy about 30% of the total volume of the organ. The posterolateral part, located behind the urethra, contains predominantly glandular tissue.

The large difference in the percentage of cancer pathologies is associated with embryonic and morphological differences between these areas. For this reason, different areas of the prostate react differently to hormonal influences. While the pathologically active peripheral region appeared to be highly susceptible to the effects of androgens, the relatively stable central region was more responsive to estrogens. This division is based both on the histological features of different parts of the gland and on their clinical significance. However, in terms of microanatomy, these zones, in turn, consist of a number of structural elements.

Structural components of the prostate

Prostatic glands are structural units of the prostate gland of the tubular-alveolar type. 30-50 pieces of such formations, grouped into lobules, are located in the posterior lateral areas of the prostate (peripheral zone). The discharge of the secreted secretion occurs through special passages that merge to form prostatic ducts that exit directly into the urethral canal in the area of ​​the seminal tubercle. Periurethral glands are located around the lumen of the urethra. In addition to glandular elements, the structure contains layers of connective tissue and muscle bundles of smooth muscle fibers. On the surface, these two non-glandular components form the gland capsule.

Histology

The glandular tissue of the prostate is heterogeneous in its structure and may include 3 types of epithelial cells:

The organ stroma is represented by two types of structural elements:

• a filling matrix of elastin and collagen fibers, glycosaminoglycan molecules;
• cellular elements in the form of fibroblast cells, smooth muscles, lining endothelium.

The connective tissue layers located between the glandular lobules pass to the outer part of the organ, forming its fibrous capsule.

Blood supply

Capsular arteries form a dense vascular network on the surface of the gland. From it, the vessels of the radial network extend inward, which run parallel to the ejaculatory ducts. From top to bottom, along the urethra, the vessels of the urethral network pass.

Each artery in the interlobular space is accompanied by 2-3 veins, which merge in the efferent flow, first into the venous subcapsular plexus, and then into the vesicoprostatic plexus.

Innervation

Both the autonomic and somatic nervous systems are involved in the innervation of the genitourinary system. In particular, the work of the prostate muscles is regulated by the sympathetic autonomic nervous system, which, among other things, is responsible for regulating the work of the bladder body, its neck, as well as the muscles and sphincters of the urethral canal.

Development of the pathological process

A variety of cellular elements can be involved in the development of prostate hyperplasia. Depending on which tissue predominates in the process of abnormal growth, glandular, stromal and mixed hyperplasia are distinguished. However, according to researchers, the beginning of the process is activated precisely in the region of the transitional glandular zone of the prostate, more precisely in its stroma. After diagnosing the problem, it is useful to conduct dynamic observations of the development of the process.

With benign hyperplasia of the transitional (transient) areas, the iron increases inward. In the images this can be seen in the form of so-called “lateral eclipse zones”. In this case, the overgrown lateral zones compress the peripheral and central areas, leading over time to the development of atrophy.

If the paraurethral zones begin to increase in size, a powerful fibromuscular layer acts as a limiter. The only direction for the growth of the gland remains along the urethra, pushing away the wall of the bladder. Another clear sign of the presence of a pathological process is a violation of the ratio of the glandular and non-glandular components of the prostate, which is clearly visible in detailed MRI images of the organ.

Causes of the pathological process

As a rule, one reason for triggering the development of pathology is not enough, so doctors tend to identify a whole package of provoking conditions:

• male gender;
• age;
• hereditary predisposition;
• hormonal changes within the body;
• chronic inflammatory process;
• infections;
• unhealthy lifestyle (reduced physical activity, poor nutrition, bad habits).

Considering the fact that male gender at an older age automatically identifies a person at risk, regular screening is recommended for early detection of a pathological process, especially a malignant type. The introduction of this practice is prompted by mild symptoms of the tumor process, especially in the early stages of development.

Ultrasound diagnostics of the prostate

The high level of development and widespread availability of ultrasound diagnostics place ultrasound at the top of the list of diagnostic procedures for identifying a tumor process in the prostate gland. The quality of the image allows you to see even the most minor deviations from the normal structure.

With a transabdominal scan of the peritoneum, a healthy ultrasound image shows:

• glandular part of the prostate (central, peripheral and transition zones) with normal homogeneous echo density;
• the non-glandular part of the prostate (anterior stroma and areas of the circular muscle layer) have an inhomogeneous structure;
• the contours of the organ are smooth, the fibromuscular capsule is clearly defined;
• dimensions do not exceed 2.4*4.5*4.1 cm;
• The prostate is located symmetrically relative to the urethral canal.

The presence of deviations is indicated by:

• diffuse compactions in the form of areas of echogenic structure without pronounced boundaries;
• areas with weak echogenic density (borders may be pronounced or absent);
• foci of high density (echogenicity is higher than in the area of ​​the fibrous capsule of the gland).

If one of these options is identified, an additional examination is prescribed using laboratory tests (blood test, urine test, biopsy), rectal palpation, uroflowmetry, CT, etc.

We must not forget that timely diagnosis of hyperplasia allows us to slow down further growth of glandular tissue and eliminate the need for surgical intervention. In the early stages of cancer development, a timely response can save or significantly add to the patient’s life. Thus, a timely ectomy or resection of the prostate gland can completely eliminate the problem without consequences for men’s health.

Many men know practically nothing about their own body, especially about the organs that are most important to them. The entire reproductive function of the male body is performed by the prostate gland, which is associated with male hormones. It is this organ that gives a man confidence and also allows him to start a full-fledged family. It is necessary to know the structure of the prostate gland and the features of the organ.

The prostate gland is an exclusively male reproductive organ. The prostate is part of the male reproductive system and is directly dependent on male hormones. The prostate gland is located in the pelvic organs, just below the bladder. The size of the iron resembles a chestnut, and the shape is an inverted trapezoid.

The prostate gland secretes a secretion that provides and influences the life of sperm. If a man has a dysfunction of the prostate, then his risk of infertility, the appearance of a malignant tumor, and problems with erection increases. As a rule, problems with the prostate gland appear in men who have reached the age of 50 years. But it is always possible to avoid illness if you know how the organ works.

Anatomy of the prostate gland in a man

Typically, the prostate gland is located in the pelvis, just below the bladder and seminal vesicles. The rectum is located behind the prostate. The prostate also covers the urethra. Because of its location, all the problems with the disease arise. If a man has prostate disease, he begins to have problems with urination, as the urinary tract becomes blocked due to the growth of the prostate gland. The vas deferens also suffer, which is why sperm does not come out, but accumulates in the bladder. Thus, a man has a problem with potency.

The problem with potency is an acute and almost taboo topic for every man. Many are afraid to talk openly about this and consult a doctor in cases where it is really necessary. Although this must be done. It is necessary to overcome the psychological barrier and let the doctor help.

Prostate secretion

The secreted secretion is the main component of procreation. It is this that affects the vital activity of sperm. In case of problems with the prostate and possible diseases, a man is temporarily or permanently deprived of the opportunity to become a father. Prostatic secretion is not easy. It contains various biological elements. For example:

1. PSA. As a rule, when any disease occurs, doctors check the PSA level using diagnostics. If it is elevated, then some kind of infection is probably developing.
2. Lemon acid. This substance is responsible for preventing the development of bladder stones. Otherwise, men may experience problems.
3. Lysozyme, prostaglandins and immunoglobulins. They are also the main component of prostatic secretion. Typically, these substances are responsible for the immune system. If the prostate gland functions normally, then it is these substances that prevent fungus and other bacteria from entering, which cause various diseases of the pelvic organs.
4. Testosterone. The main male hormone, which is responsible for the entire body and appearance. It is this that influences increased vegetation, sexual activity, etc.
5. Enzymes and vitamins that enter the body and provide sperm with sufficient immunity to normally maintain vital functions for several hours.
6. Juice. It is this substance that is responsible for sperm motility.