What are the divisions of the prostate gland. Areas of the prostate. Ultrasound anatomy of the prostate

The human body has many vital organs and systems that help it stay healthy. One of the most important elements in this list is Often people know almost nothing about the structure of the prostate, which is responsible for the proper functioning of the reproductive and urinary systems. Very often, men pay attention to it too late, when failures and changes begin, dangerous not only for health, but also for life.

Let's learn more about this mysterious, incomprehensible organ in this article in order to understand and prevent many unpleasant moments.

general information

The prostate begins to form at an early stage of embryogenesis, in the first months of embryonic development. It is formed by protrusion of the genital urosinus. During fetal development in men, growth factors of nervous tissues develop in the gland, which further determine the development of the peripheral nervous system.

Although the gland is called the auxiliary organ of a man, not a single system in the body can do the same thing that it can. The prostate produces a special substance called secretion, which is vital for spermatozoa. A healthy man produces 0.2 ml of fluid daily. The secretion of the gland is rich in various nutrients that sperm cells need during their movement through the female genital tract to fertilize the egg.

In the structure of the prostate, enzymes are present in large quantities, in particular, a prostate-specific antigen involved in the liquefaction of sperm. Thus, it affects the activity and vital activity of spermatozoa.

Any malfunction of the organ affects the health of a man, and this can cause infertility.

The structure of the prostate

The prostate gland is part of the male reproductive system and is located directly below the bladder. It encircles the proximal urethra, which extends from the neck of the bladder to the end of the penis. The proximal end surrounding the urethra is round, while the distal end tapers and appears blunt.

The gland is about the size of a walnut and weighs approximately 20 grams. It includes 70% of the mass of the glandular type, as well as smooth muscles and fibrous tissues. This structure is complemented by 50 vas deferens, passing through a part of the urethra, known as the prostatic, as well as two ejacular canals. The organ is surrounded by a thick fibromuscular layer.

Structurally, the structure of the prostate can be divided into zones or lobes as follows: peripheral, central, transitional and fibromuscular zones, or anterior, posterior, lateral and middle lobes.

The transition zone or anterior lobe is associated with a condition known as benign hyperplasia. This mass is a benign tumor and is found mainly in the anterior region, while the peripheral and posterior zones or the posterior lobe are usually associated with prostate cancer.

Production and storage of seminal fluid

Most of you will be surprised to know that about a third of semen is actually released from the prostate gland, but it is.

Due to the fact that the male structure of the prostate and testicles are closely related, when the seed is ejected from the scrotum, it enters the gland, where it mixes with a special alkaline secret secreted by the organ, which blocks the protective functions of the acidic environment in the female genital canal. Thus, it allows the spermatozoa to penetrate and reach the fallopian tubes.

The secret contains the PSA enzyme, citric acid and calcium.

Thus, we can say that one of the most important tasks in the male body is the release of fluid at the time of ejaculation.

The prostate is also a storage site which is partly produced by seminal vesicles or vesicles.

The secretion of prostatic fluid is influenced by male sex hormones, mainly testosterone.

Mixing substances

Due to its structure and function, the prostate performs the task of mixing. The seminal vesicles are used to transport sperm from the testicles. When they reach the organ, they mix there with its own fluids.

Very few may be aware that PSA (prostate specific antigen) is also produced inside the prostate gland. The enzyme in large quantities begins to be released into the blood during cancerous processes and is a tumor marker, which is taken when cancer or prostate adenoma is suspected.

In fact, there is a lot of controversy regarding the validity of this test, as well as its results and variation with several other factors associated with it.

PSA helps sperm stay active inside the uterus by keeping it in a liquid form. Another enzyme performs a preventive action against a special enzyme that makes sperm sticky. As the fluid enters the female body, the PSA begins to dissolve the enzyme, which eventually releases the sperm so they can move forward to the uterus and fertilize the egg effectively.

muscle contraction

And the structure helps her smooth muscles contract during ejaculation, increasing the spread of sperm and seminal fluid along with the secret. Her muscles contribute to the process of ejaculation.

It is believed that the muscles of the organ act spontaneously, without human intervention, and prevent urine from entering the urethra at the time of ejaculation.

The gland also helps to expel sperm through the penis, which is why in medicine it is considered an essential muscle of the male body. She needs a lot of strength in order to develop a high speed of ejection of fluid from her channels so that it easily reaches the cervix.

Interestingly, the male G-spot is located in this gland, so prostate stimulation is used to improve sexual responses.

Filtration of toxins

Another valuable function of the prostate, the structure of the gland determines this, is the ability to filter. Since the reproductive system is extremely important for the body, the gland helps to remove and neutralize all toxins, so that the sperm remains completely safe. Without a doubt, this is one of the main duties of the gland. It helps to improve a man's overall health and naturally avoid life-threatening diseases such as prostatitis, cancer and other problems.

fluid secretion

One of the more necessary features of the structure of the prostate in men is the protection of the urethra with its secretion, providing protection from various infections associated with the urinary tract. These diseases are quite rare in the male body, compared to the female body, so it can be said that prostate secretions are doing their job perfectly.

Urination control

An important function of the prostate - its structure allows you to control the flow of urine. The specific part of the urethra that runs along the prostate gland is known as the prostate. The prostate helps surround the urethra just below the bladder so that fluid flow can be easily controlled. This structural feature helps protect the ejaculate from damage during urination or orgasm.

Two small muscles in the prostate, well known as sphincters, work like gatekeepers to regulate the shutoff valves. These guardians control the flow of fluids at the right time, distinguishing between ejaculation and urine.

If the sphincters are damaged, semen can enter the bladder. This process disrupts normal urination and causes retrograde ejaculation. A patient with this problem needs surgery.

Removal of substances into the blood and lymph

The gland produces the necessary elements for the human body. One of the most important enzymes produced by the prostate gland is known as alpha reductase. This enzyme helps convert testosterone to DHT (dehydrotestosterone), which is 10 times more potent.

The main task of DHT is to control sexual desire.

As the prostate gland and the structure of the organ allow it to function as a filter, testosterone levels are also controlled. If it lingers in the gland for a long time, it can begin to affect the production of the necessary enzymes. Ultimately, this leads to a decrease in sex drive. DHT helps keep you safe from all these troubles.

Dihydrotestosterone is a hormone molecule. Many people are under the misconception that testosterone and DHT lead to various problems in the prostate. In fact, this is due to an excessive increase in estrogen levels.

Everyone should understand that any prostate surgery can lead to major sexual problems. Be more mindful of this while protecting the prostate, and it will help you enjoy a healthy life and normal functioning of the reproductive system.

Diseases of the prostate

The prostate gland is an organ that grows and develops during childhood and adolescence, during puberty. Then it freezes for many years and is at rest for up to 50 years. Unfortunately, in the future, the structure of the prostate changes, the gland gradually increases in size and can cause many problems.

In addition to benign prostatic hyperplasia (adenoma), which leads to urinary incontinence, infections and bladder stones and cancer, another important functional and structural disorder of the prostate is prostatitis. This is an inflammatory process, and in some cases, antibiotic treatment will be needed to alleviate its symptoms.

In old age, the prostate is an organ that can lead to several problems. Most of them are treatable, and early diagnosis will contribute to a positive outcome in the treatment of prostate cancer.

In any case, problems related to the functions of the prostate should be treated by a urologist.

Take care of your health, pay attention to any changes in your body and do not be afraid to consult a doctor. Never forget that early diagnosis and medical attention can save your life!

The prostate is a chestnut-shaped organ of a man and is directly involved in the implementation of the reproductive function.

It is classified as an unpaired organ. Its texture is dense and elastic.

The gland has muscle cells and tissue that plays a supporting role in. It is surrounded by a capsule on all sides. The organ is located in the small pelvis under the bladder.

The organ consists of thirty or more glands and a muscular substance that represents the stroma of the prostate.. Since the glandular region of the organ occupies about a third of the tissues in the capsule, according to modern terminology, the term “prostate gland” is no longer used.

Anatomy of the prostate

The organ is located in the middle abdominal floor of the small pelvis. It has the shape of a cone, the top of which is directed downward. The base is located just below the lower part of the bladder. The prostate consists of two halves (lobes) and an isthmus.

It covers the beginning of the urethra leaving the bladder. The organ is distinguished by a well-visible from all sides, except for the base, the so-called capsule. Directly above the prostate are located: the base of the bladder, testes and ampullae of the vas deferens.

The urogenital diaphragm is located a little lower, in front is the back surface of the pubic joint, and behind is the ampulla of the final part of the digestive system.

Organ Shape

This is the main gland that performs a vital function. equal to 24 ml.

The average density is 1.04 g / cm³. The length of the prostate varies from 2.8 to 4.8 cm. The width is 2.5 - 5 cm, and the thickness is 1.6 - 2.8 cm. In different age periods, the shape and volume of the gland are radically different. Until puberty, the organ has small dimensions and consists only of muscles.

But after 13 - 15 years, the first glandular inclusions begin to appear. The prostate in mature men consists of a homogeneous glandular tissue - connective and smooth muscle.

The structure of the prostate gland in men

It is located in the central part of the small pelvis. It is located between the pubis and the rectum under the base of the bladder. The organ slightly covers the urethral canal.

The prostate gland consists of the following parts:

What is the capsule of the prostate?

The outer layer of the gland is called the capsule.

This is a fairly thin film that adheres closely to the tissue of the organ. Accumulations of connective tissue fibers - the septa of the prostate - go inward from it.

The glandular tissue forms autonomous complexes in the form of lobules of the alveolar tubular structure. Their number ranges from thirty to forty.

There are almost no lobules in the anterior part of the prostate. Here, smooth muscles predominate, which are concentrated near the lumen of the urethral canal.

What are the parts of the vas deferens?

The ducts are completely identical organs of the male urinary system, which are about 49 cm long. The diameter of each of them is 3 mm. They are a continuation of the epididymis.

It is important to note that the vas deferens has four main parts:

1. short testicular(located behind the gonad, closer to the median part of its appendage);
2. cord(rises slightly up in the composition of the spermatic cord medially from its capillaries). Reaches the groin;
3. inguinal(passes directly into the inguinal canal);
4. pelvic(lateral side of the pelvis).

Main functions of the prostate

The gland performs three essential functions:

Due to the numerous unique substances contained in the secret of the organ (spermine, lysozyme, zinc-peptide complex, polyamine), a barrier appears that inhibits the reproduction and subsequent penetration of microbes into the organs of the genitourinary system.

Thus, the infection cannot get inside.

The most dangerous ailments are bacterial. The latter type is more common in mature men who are over forty-five years old. If the body works without failures, then no pathologies are terrible for it.

Diseases of the gland are very common. Therefore, you need to monitor your health and at the slightest sign of a deterioration in the work of the prostate, you must immediately. This will help preserve your life and the normal performance of the whole organism.

Related videos

About the surgical anatomy of the prostate gland in men in the video:

The prostate is an important organ that ensures the normal functionality of the entire urinary system. His diseases appear due to genetic predisposition and sexually transmitted diseases.

Any, even the most insignificant violation in the work of the gland, can lead to the appearance of various problems in other important areas of the body.

and anterior urogenital diaphragm. The gland covers the initial part, its prostatic part, pars prostatica, and also, ductus ejaculatorii.

According to its structure, it belongs to the complex alveolar-tubular glands. The prostate is shaped like a chestnut. It distinguishes downward, towards the urogenital diaphragm, a narrower apex of the prostate, apex prostatae, and a wide, with a concave surface, directed towards the bladder, the base of the prostate, 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 lower lateral surfaces, facies inferolaterales, which are turned to the right and left sides, respectively, to the muscle that lifts the anus, m. levator ani. A small pubic-prostate muscle departs from the latter, m. puboprostaticus, which attaches to the inferolateral surface of the prostate gland.

AT prostate allocate the right and left lobes, lobus dexter et lobus sinister. The lobes are separated along the posterior surface of the gland by an unsharply pronounced groove and isthmus of the prostate gland, isthmus prostatae (middle lobe, lobus medius).

isthmus prostate its area is called, 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 middle lobe, lobus medius.

The urethra passes through the anteroinferior part of the gland, penetrating its apex, so that the greater part of the gland lies behind the canal, and the smaller part lies in front. In the direction from top to bottom forward through the base of the gland, the ejaculatory ducts pass.

transverse prostate length about 4 cm, longitudinal - 3 cm, and thickness 2 cm; the mass of the gland is on average 20 g. The size and mass 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 a parenchyma, parenchyma, and a muscular substance, substantia muscularis. The parenchyma is unevenly distributed throughout the organ; towards the rectum, the glandular parenchyma predominates, while towards the urethra, the muscular substance is more developed.

The glandular parenchyma surrounds the prostatic 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 passages are located in front; the most anterior median area is free of them and contains only muscle substance.

The gland is surrounded by a capsule of the prostate gland, 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.

Muscle fibers pass into the gland from the wall of the bladder adjacent to its base. The top of the gland, which lies in the urogenital diaphragm, contains striated muscle fibers passing from the latter, which form part of an arbitrary muscle - the sphincter of the urethra, m. sphincter urethrae. The mouths of the glandular ducts, about 30, open on the surface of the mucous membrane of the prostatic urethra around the seminal hillock and on it.

Anterior surface of the gland formed by its smallest department, located in front of the urethra. From the pubic fusion 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).

In front of the base of the gland adjoins, fusing with it, the bottom of the bladder. The bodies of the seminal vesicles adjoin the posterior part of the base laterally, and the ampullae of the vas deferens medially.

The posterior surface of the gland is adjacent to the septum separating it from the ampulla of the rectum and constituting the posterior wall of its capsule.

The lower lateral surfaces of the gland, being separated by the wall of the capsule, are adjacent to the medial edges of both muscles that lift the anus, which, when contracted, can lift the prostate gland.

Under the capsule of the gland there are veins that enter the prostate 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 seed mound of the canal; it looks like a longitudinal 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: aa. rectales media, vesicalis inferior. Venous blood flows through the plexus venosus prostaticus, then through the vv. vesicales inferiores in v. iliaca interna.

Lymphatic vessels divert lymph to nodi lymphatici iliaci interni.

You will be interested in this read:

Chapter 16

RADIATION ANATOMY OF THE PROSTATE

MEN

NORMAL AND TOPOGRAPHIC ANATOMY OF THE PROSTATE

The prostate gland is located in the lower anterior third of the small 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, 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 in anatomical and functional terms it is a single organ. The base of the gland faces the bottom of the bladder, the top is adjacent to the urogenital diaphragm. The posterior surface of the prostate borders on 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 in the thickness of the prostate down, 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 release secretions into the composition of the semen, the contraction of the sphincter prevents urine from entering the urethra during ejaculation. A powerful muscular component surrounds the prostatic urethra. There are the following fibromuscular zones:

1) 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 that differ from each other in histogenesis and ability to metaplasia. Each of the types of epithelial cells 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 - urinary bladder; 2 - seminal vesicles; 3 - preprostatic sphincter; 4 - vas deferens; 5 - capsule of the prostate gland; 6 - rectum; 7 - prostatic urethra; 8 - urogenital diaphragm; 9 - bulbourethral glands; 10 - membranous urethra; 11 - prostate gland; 12 - anterior fibromascular zone; 13 - periprostatic fiber; 14 - base of the prostate gland; 15 - bladder neck; 16 - pubic articulation; 17 - bladder wall; 18 - the bottom of the bladder; 19 - the mouth of the ureter.

Epithelial (glandular) zones of the prostate gland

1. Central zones located along the urethra. On longitudinal sections, they look like a cone, tapering from the base of the prostate to its apex. On transverse sections, each of these zones looks like a truncated oval with a depression in the medial part. In the area of ​​these depressions, there are lumens of the vas deferens. The largest number of cells of the central zone is located at the posterior surface of the gland. In the region 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 center. They occupy the main part of the prostate gland, spreading to the top of the organ. Shown as crescents

in the lateral parts of the gland. In most cases, prostate cancer develops as a result of metaplasia of cells located in 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 development of prostate adenomas.

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

The vascular anatomy of the prostate gland is fully consistent with its zonal structure. The blood supply is carried out by the prostatic arteries, which are a continuation of the inferior cystic arteries. From the prostatic arteries to the inner part of the gland, the urethral arteries depart, and to the outer part - the capsular arteries. 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

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

Sonographically unchanged prostate gland with longitudinal transabdominal scanning has the form of a cone-shaped formation with clear contours, located behind the bladder. The gland capsule appears as a hyperechoic structure 1–2 mm thick. The tissue of the prostate gland has a fairly homogeneous fine-dotted structure. With echography performed in a strictly sagittal plane, the neck of the bladder is clearly visualized. In a number of patients, the anterior fibromuscular zone and the prostatic urethra are defined as hypoechoic zones. When the transducer is tilted away from the midline, the prostate lobes and seminal vesicles are displayed. Seminal vesicles are defined as paired hypoechoic formations located on the posterolateral surfaces of the base of the gland (Fig. 16.3). On transverse echograms, the prostate gland is a round or ovoid formation (Fig. 16.4). The bladder is visualized anterior to it, the rectum is visualized posteriorly. Normally, according to N.S. Ignashin, the upper-lower 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. prostate ultrasound

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 intact prostate gland has

the shape of an elongated cone, tapering from its base to the top, slightly deviating anteriorly. The parenchyma of the gland has a fine granular structure. On echograms, one can distinguish between central and peripheral zones. The peripheral zone is characterized by medium echogenicity, has a homogeneous structure. The central zone is less echogenic, 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 of 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, which is localized in the anterior sections 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 limited 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 revealed - periprostatic tissue. 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 up to 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 (CDI) and power Doppler mapping (EDC) makes it possible to get an idea of ​​the vascular anatomy of the prostate gland.

The study in the CFM mode allows all patients to visualize and evaluate the course and direction of the prostatic and urethral arteries in the normal state. Capsular arteries, due to the physical features of this method, do not receive their image in color flow. In the EDC mode, it is possible to trace the course of all intraprostatic vessels.

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

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

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

To assess arterial blood flow in the mode of pulsed Doppler scanning, the maximum systolic velocity, indices of resistance (R^) and pulsation (Pi) are calculated. The density of the vascular network is also estimated. The prostatic artery has a high, narrow, sharp systolic peak and a low-amplitude, gentle diastolic peak. The values ​​of peak blood flow velocities in the prostatic artery are on 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 with each other, they have a wide, sharp systolic peak and a gentle diastolic peak. The values ​​of peak blood flow velocities and the 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 veins of the prostate are a mean-amplitude straight line. The average speed in the veins of the prostate varies from 4 cm/s to 27 cm/s, averaging 7.9 cm/s.

CT ANATOMY OF THE PROSTATE

On CT, the intact prostate gland is displayed as a homogeneous structure with a densitometric density of 30-65 HU (Fig. 16.5). It is located on sections, below the exit of the urethra from the bladder. The seminal vesicles are located behind the posterior wall of the bladder, surrounded by fatty tissue. They are located at an angle to each other. They have the appearance 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 peritoneal-perineal fascia. Next to the seminal vesicles are the ureters, which are crossed in the medial direction by the vas deferens. small CT

Rice. 16.5. CT scan of the prostate.

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

the pelvis is highly informative in determining the anatomical and topographic relationships, however, it 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.

PROSTATE ANATOMY ABOUT MRI IMAGE

MRI 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 state of surrounding tissues and organs. When using devices with a high magnetic field strength, it is possible to visualize various anatomical structures: the fibromuscular zone, the central, transitional and peripheral zones. Seminal vesicles, prostatic urethra, seminal tubercle and gland capsule are well differentiated. The most clearly zonal structure of the prostate gland is displayed on T2-WI. The peripheral zone has a high signal intensity, the transitional and fibromuscular zones have a low one, the central zone is represented by signals of medium intensity (Fig. 16.6-16.8).

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

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 the normal prostate. T2-VI. Axial plane.

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

Literature

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

2. Zubarev A.V., Gazhonova V.E. Diagnostic ultrasound. Diagnostic ultrasound. Uronephrology.- M.: Firma Strom LLC, 2002.- S. 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. TsybA.F., Grishin G.I., Nestaiko G.V. Ultrasound tomography and targeted biopsy in the diagnosis of pelvic tumors.- M.: Kabur, 1994.- S. 31-39.

5. Aarning R.G. etal. Technical aspects of transrectal ultrasound of prostate.- Nigmegen Netherland, 1996.- P. 71.

6. HigginsSW., 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. Robert 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.

The prostate performs a number of important functions in the body:

1. Secretory. The secret produced by this organ includes a liquid and a dense fraction. It consists of proteins, electrolytes, fats and hormones that play a leading role in the functioning of the reproductive system.
2. Transport. Due to the contraction of the smooth muscle fibers of the seminal vesicles and prostate capsules, the process of ejaculation occurs - the release of seminal fluid into the urethra.
3. Thinning. The mobility and viability of spermatozoa is ensured by the liquefaction of sperm, which occurs due to the prostate gland.
4. Barrier. Thanks to it, the penetration of pathogenic bacteria from the urethra into the cavity of the upper urinary tract is difficult.

REFERENCE! The prostate is also involved in the regulation of testosterone synthesis and ensures the quality of the erection mechanism.

What produces?

The prostate gland secretes a liquid that has a specific odor and has a slightly alkaline reaction.

The composition of this liquid includes enzymes, amino acids, lipids, proteins, citric acid.

In addition, it contains sulfur, potassium, calcium, phosphorus, sodium, zinc and chlorine.