Male urethra starts at the bottom Bladder internal opening, ostium urethrae internum, and ends on the head of the penis with an external opening, ostium urethrae externum. Its length is 20-22 cm.
In the urethra several parts are distinguished.
1. Intrawall part (preprostatic part), pars intramuralis (pars preprostatica) of the male urethra.
2. Prostatic part of the male urethra, pars prostatica.
3. The intermediate part of the male urethra (membranous part), pars intermedia (pars membranacea).
4. The spongy part of the male urethra, pars spongiosa.
First, intramural part of the male urethra is actually a continuation of the neck of the bladder, the muscle bundles of which cover the beginning of the urethra. These muscle bundles are isolated under the name of the involuntary internal urethral sphincter, m. sphincter urethrae internus. Outside of urination, the pars intramuralis is closed.
Prostatic part of the male urethra the widest, the diameter of its middle (sinus prostaticus) is 11 - 12.5 mm. The length of the prostatic part is 3-4 cm. The urethra passes in it in front of the middle lobe in the form of a slightly curved arc, convexly facing backwards. The prostatic uterus, utriculus prostaticus, and the paired ductus ejaculatorius open into the prostatic part of the urethra on the seminal mound, colliculus seminalis, and the ductuli prostatici open on the sides of the seminal mound in the sinus prostaticus.
Intermediate part of the male urethra, pars intermedia, was formerly called membranous (pars membranacea). Currently, this part of the urethra is defined as located between the prostatic and spongy parts, that is, from the distal end of the seminal hill to the membrana perinei (fascia urogenitalis inferior). This is the shortest (1.5-2.5 cm) and most narrow part urethra. This narrowness is due to the circular striated muscle, m. sphincter urethrae externus, which is a voluntary sphincter of the urethra. The sphincter lies in the same layer with the deep transverse perineal muscle, the lower surface of which is covered by the membrana perinei. Outside, on the sides of the external sphincter, there are paired bulbourethral glands, glandulae bulbourethrales (Cooper's glands).
Spongy part of the male urethra has a length of 14-15 cm. It is located 1.5-2 cm downward from the symphysis. After passing through the perineal membrane, the urethra enters the bulbus penis and then goes into the corpus spongiosum penis to the external opening. The ducts of the bulbourethral glands flow into the bulb.
Urethra They are also divided into fixed and movable sections. The first includes the first three parts of the urethra, that is, intramural, prostatic and intermediate, as well as the initial (bulbar) part of the spongy part. The mobile section makes up the pars spongiosa. The boundary between them is determined by the ligament that suspends the penis. As a result, two curvatures are formed along the urethra: subpubic, fixed, with its convexity directed downward and posteriorly, and prepubic, mobile, with its convexity directed forward and upward. By lifting the movable part of the penis up to the abdomen, one bulge can be eliminated, and then the course of the urethra will resemble Latin letter U, that is, one common bend will be preserved. This greatly facilitates the insertion of metal instruments (catheter, cystoscope, etc.) into the urethra.
During catheterization of the male urethra you need to remember that the urethra has three narrowings: at the internal sphincter, at the external sphincter (the narrowest part) and at the external opening of the urethra. However, the walls of the urethra are elastic and allow instruments with a diameter of up to 10 mm (bougie, catheter) to pass through.
Blood supply to the male urethra carried out at the expense of a. Pudenda interna. Outflow venous blood occurs through the veins of the penis in venous plexus Bladder.
Innervation of the male urethra carried out from the genital plexus.
Lymphatic drainage from the male urethra occurs in the inguinal lymph nodes.
The urethra or urethra refers to the excretory organs as well as the kidneys, ureters, and bladder.
If we talk in simple language, then - this is a tube, which in women is intended for the removal of urine, and in men for the release of urine and sperm.
We’ll talk further about what this organ is, what it consists of, and how it functions.
Similarities and differences
The human urethra, or urinary tract, is a tubular organ that runs from the bladder to the external genitalia. In men and women, it differs in its structure and colonization by microflora.
The organ in both sexes resembles a soft, elastic tube.
Its walls consist of 3 layers:
In men, the urinary tract passes through the penis to the outlet and serves to drain urine and release ejaculate during orgasm. In women, it goes from the bladder to the external opening, which is located between the clitoris and vagina, and is needed only for the removal of urine.
The external urethral sphincter is formed as paired muscles. It compresses part of the urethra. IN female body these muscles are attached to the vaginal area and are capable of compressing it.
The muscles of the urethra in men are connected to the prostate. The internal sphincter has a fairly strong muscle located near the exit from the bladder.
Microflora in the organ
The channel for excreting urine in representatives of different sexes differs in microflora. Immediately after the birth of a child, various microorganisms enter his skin. They gradually penetrate into the body and settle on the mucous membranes and internal organs.
Bacteria cannot penetrate further than the mucous membranes; this process is hampered by the body's internal secretions, urine, and ciliated epithelium, so they become attached to them. Pathogenic organisms that remain on the mucous membranes become the innate human microflora. 
The female urethral mucosa contains several times more bacteria than the male urethral mucosa. It is dominated by lactobacilli and bifidobacteria. They produce acid, creating an acidic environment. If there are few bacteria, then acidic environment is replaced by alkaline, which allows inflammatory processes to develop.
As we grow older, the beneficial microflora in the female urethra becomes coccal. The microflora of the male urethra is represented by streptococci, corynebacteria, and staphylococci; it does not change throughout life.
The composition of microflora may vary depending on large quantity sexual partners. Frequently changing partners introduces dangerous microbes into the body that can cause serious illness.
Men's channel
The male urethra during the embryonic period is similar to the female one, as it consists of the same structures. And once formed, it begins to differ significantly, becomes longer and smaller in diameter, is located inside the penis, and its functions, in addition to urine output, also include ejaculation.
Redistributing these functions male body depends entirely on the degree of blood filling of the corpora cavernosa and corpus spongiosum that surround the male urethra. With erection, the blood supply to the penis occurs, ejaculation occurs, and in the absence of blood supply to the penis, the process of urination occurs.
The male urinary canal has a length of 18-22 cm. In a state of excitement, the length becomes a third longer, in boys before puberty it is a third less.
The urethra in men is divided into posterior (the distance from the internal opening to the beginning of the corpus cavernosum) and anterior (the remotely located part of the canal).
It has two bends in the shape of the letter S:
- The upper (infrapubic) bend bends around the pubic symphysis (half-joint) from below as it passes from top to bottom of the membranous part of the urethra into the cavernous one.
- The lower one (prepubic, prepubic) is located at the point of its transition from the fixed part of the urethra to the mobile one.
When the penis is raised, both curves form one common one, the concavity of which is directed forward and upward.
Throughout its entire length, the male urethra is not the same in lumen diameter; narrow parts alternate with wide ones.
The extensions are located in the prostatic, bulbous part and at the end of the urethral canal (where the scaphoid notch is located). The narrowings are located at the internal opening of the urinary canal, in the area of the urogenital diaphragm, at the external opening of the urethra.
Conventionally, the male urethra is divided into 3 parts:
- Prostatic(prostatic). It has a length of 0.5-1.5 cm. It consists of tubules for ejaculate release and 2 ducts (prostatic and sperm excretory).
- Sponginous(spongy). The urethral part is located along the penis in its lower part and has a length of 13-16 cm.
- Cavernous(membranous). The longest section of the male urethra, the length of which is approximately 20 cm. The spongy section contains ducts of numerous small tubules. It is located deep in the perineum, passes through the urogenital diaphragm, which has a muscular sphincter.
The male urethra originates from the urinary sac. Smoothly moving into the prostate area, it crosses this gland and ends at the head of the penis, where urine and seminal fluid come out.
The average size of the urethral lumen in men along its entire length is 4-7 mm, in boys 3-6 mm.
Female urinary tube
The female urethra is an anteriorly directed, straight tube passing close to the elastic vaginal wall and pubic bone. Its length is 4.8-5 cm, and its diameter is 10 - 15 mm, while it is easily stretched.
Inside, the urinary canal is lined with a mucous membrane, which has the appearance of longitudinal folds, due to which the urethral lumen appears smaller. In the female urethra there is a special obstructing pad consisting of connective tissue, veins, elastic threads. It closes the duct of the urinary canal.
The female urethra does not perform reproductive functions, although substances are released through it that can be used to determine whether a woman is pregnant or not. The female urethra is surrounded by tissues that are similar in structure to the corpus spongiosum of the penis, and the corpus cavernosum of the clitoris, which is similar to the corpus cavernosum of the penis, is located in front of the urethra.
The urethra itself is hidden in the tissues of the pelvis and therefore does not have mobility. Its anterior surface is adjacent to the tissues that cover the pubic symphysis, and in distant places to the legs of the clitoris. The posterior surface of the external urethral outlet is adjacent to the anterior wall of the vagina.
It is closely connected to the anterior wall of the vagina and is firmly attached to the lower branches of the pubic bones, as well as partially to the ischial bones.
Since it is short and wide in women, located next to the vagina and anus, the danger of bacteria, microbes and other pathogenic microflora entering it is much higher in women than in men. Therefore, they are more susceptible to genitourinary infections.
External hole
In the male half of humanity, the main part of the urethra passes inside the penis, and the outlet is located at the top of its head. If it is not there, such a violation is called. If there is partial or complete clefting of the anterior wall of the urethra, the disorder is called.
The external urethral canal in the fair sex is located between the clitoris (slightly below it by about 3 mm) and the entrance to the vagina.
The location of the external opening may vary. If the lower wall is underdeveloped, it will be located on the anterior wall of the vagina, distant from the entrance.
This process is called hypospadias. The outer hole has a diameter of approximately 0.5 cm, its shape can be round or star-shaped.
Functions of the urethra
The organ performs not exactly the same functions in representatives of different sexes. The urethra in the fair sex is intended exclusively for holding urine in the bladder and removing it from the body. It has no other functions.
The male urethra has 3 functions:
- Retains urine in the bladder. This process occurs due to the internal and external sphincters, which close the urethra. When the bladder is half full, the internal sphincter plays a big role. When the bladder overflows, the external sphincter comes into play.
- Removing urine from the body. If there is more than 250 ml of urine in the bladder, a man has the urge to go to the toilet. At the same time, the muscles of the external sphincter relax, and under the influence of the contractile actions of the bladder and abdominal wall urine begins to come out. It is released with great force at first, and then the stream becomes weaker and shorter.
- Release of seminal fluid during orgasm. The internal sphincter contracts, causing the seminal mound to swell, the prostate muscles to contract, and the external sphincter muscles to relax. The ejaculate is ejected in shocks due to the contractile movements of the seminiferous mounds, prostate muscles, ejaculatory duct, and contractions of the bulbospongiosus muscles.
The urethra is an organ of the human urinary system designed to remove fluids from the human body.
Although in men and women it differs in structure, location, and functions, representatives of both sexes need to monitor the health of the urethra, because problems with it can significantly complicate life.
Urinary incontinence is the process of involuntary urination that occurs as a result of poor hygiene and various colds. This disease is a problem throughout the world and is quite common. Urinary incontinence can affect both men and women equally. For a more complete understanding of this disease, it is worth taking a closer look at how the urinary system of the human body works.
Urine is formed in the kidneys after blood is filtered. Urine passes through the ureters into the bladder, where it accumulates until a certain point. When it accumulates sufficient quantity urine to remove it, a signal is sent to the human brain, which carries the information of the urge to remove unnecessary fluid. If exceeded permissible norm volume of fluid, the bladder may empty involuntarily, to avoid bladder rupture. If urination occurs unexpectedly for a person, that is, a weak signal is sent to the brain that a person is not able to feel, this means that the person needs to begin treatment for the urethral sphincter.
The sphincters that compress the entrance to the urethra are controlled by the cerebral cortex. Normal person can independently control the process of urination within reasonable limits. When urinating, the cerebral cortex sends signals to the bladder, in which the bladder itself contracts and the sphincters unclench. But with some problems, the brain loses control over urination and the bladder empties without “permission.”
The nature of the disease of the urethral sphincter.
Drug treatment of the urethra depends on the nature of the disease.
- Stressful.
- Mixed.
- Urgent or imperative.
- Involuntary urination due to bladder overflow.
- Functional.
Stress incontinence is defined by a disruption of the mechanism that prevents bladder emptying. Sometimes it can even occur during sneezing, quickly climbing stairs, running and other active dynamic movements, during which intra-abdominal pressure increases. This type of incontinence often occurs in patients who have undergone prostate surgery associated with cancerous tumors and hyperplasia prostate gland. Also, the reason may be a weakening of the pelvic muscles, which can lead to sagging of the bladder. Sagging of the bladder can lead to compression of the bladder neck and its angle in relation to the urethra. The resulting pressure then prevents the internal sphincter from closing completely, which can lead to sphincter rupture.
Urgent or imperative incontinence always follows a strong urge that requires immediate urination. Usually occurs completely unexpectedly. This type of incontinence is often the main symptom of an overactive urethra.
Involuntary urination occurs when the bladder is unable to empty completely due to reduced bladder activity or any obstruction to the flow of urine. The bladder does not empty completely, so it increases in size, as a result of which the internal sphincter stretches and urine flows out. This may be due to damage spinal cord or complications of certain diseases, such as diabetes.
Functional incontinence is determined mental illness patient, for example, with fear or reluctance to go to the toilet, as well as in people in a state of severe depression.
Risk groups for urge urinary incontinence include smokers, patients diabetes mellitus and infections urinary tract, elderly people, obese people, etc.
Mental state of the patient and treatment of involuntary urination.
The consequences of urinary incontinence are not always fatal, but quite unpleasant. From medical consequences It can be noted that the chance of urinary tract infection and perineal skin irritation increases. But more attention should be paid to the psychological consequences. The patient may experience embarrassment, awkwardness, and a feeling of helplessness. Confusion when communicating with a doctor will hinder the correct diagnosis and treatment. To avoid getting their laundry wet and spreading the characteristic smell, people try to stay at home as much as possible, some become real hermits. Severe cases incontinence often requires the insertion of a special tube directly into the urethra, through which fluid flows into an external container. As a result, bacterial infection of the urinary system and bedsores of the urethra may occur.
There are many treatment options for the urethral sphincter; the doctor can decide on the course of treatment, taking into account the characteristics of the patient’s disease.
Treatment of urethral disease can be carried out either through a course of drug therapy or surgical intervention. Of course, this depends on the neglect of the disease of the urinary and urinary system.
For urgent or mixed types of incontinence, anticholinergic drugs, adrenergic blockers, antidepressants and injections into the bladder are used, which reduce the sensitivity of the bladder to periodic nerve impulses. In conditions of stress incontinence, it can be used folk remedies, good results are also provided by special surgical techniques, and spectrum medications, such as antidepressants, duloxetine, adrenergic agonists.
Male urethra, or urethra, urethra masculina, is a hollow unpaired organ. It has the shape of a tube that begins with an internal opening, ostium urethrae internum, in the anterior inferior part of the bladder and ends with an external opening, ostium urethrae externum, on the head. There are three parts of the urethra:
- Prostatic part, pars prostatica;
- Membranous part, pars membranacea;
- Spongy part, pars spongiosa.
Prostatic part, pars prostatica, the urethra penetrates the prostate gland in a vertical direction. Its length is 30-35 mm. The middle section of the prostatic part is expanded, and the initial and final sections are narrowed. On back wall In the prostatic part of the urethra there is a seminal tubercle, colliculus seminalis, and on the sides of the tubercle there are numerous excretory ducts.
Membranous part, pars membranacea, the urethra penetrates the urogenital diaphragm with a length of 15-20 mm from the apex of the prostate gland to the bulbuspenis. The diameter of the membranous part ranges from 3-4 mm. This is the narrowest part of the urethra, which must be taken into account when inserting instruments through the urethra into the bladder. The membranous part of the urethra is limited by tufts of striated and smooth muscles, which form the voluntary closure of the urethra, m. sphincter urethrae.
Spongy part, pars spongiosa, is the longest part of the urethra, its length is 100-120 mm. The urethra is divided into bulbous and hanging sections, the lumen diameter is 6-10 mm. Numerous urethral glands, gll, open into the bulbous section of the urethra. urethrales, and ducts of the bulbourethral glands, gll. bulbourethral (Cowperi).
The male urethra has three narrowings: at the internal opening, in the membranous part and at the external opening, as well as an expansion: in the prostatic part, in the bulb of the male penis and in front of the external opening, in the navicular fossa, fossa navicularis. Along the entire length of the urethra, two bends are formed in the sagittal plane - upper and lower. In children, the prostatic part of the canal is longer. The lumen of the urethra expands when sperm and urine pass through, and when a catheter or cystoscope is inserted into the urethra.
In clinical practice, the urethra is divided into two sections: the posterior part is fixed and the anterior part is mobile. The fixed section, in turn, is divided into intravesical (5-6 mm long), prostatic (30-35 mm) and membranous (15-20 mm). The intravesical section is the sphincter of the bladder.
The structure of the male urethra
The wall of the urethra consists of three membranes:- Mucous membrane, tunica mucosa;
- Submucosa, tela submucosa;
- Muscular membrane, tunica muscularis.
In the spongy part there is no muscular layer. The mucous membrane contains many mucous glands, gll. urethrales. In the submucosal layer there are peri-urinary lacunae, which can be the site of specific and nonspecific inflammation. The muscular coat is well developed in the prostatic and membranous parts and has two layers: the inner - longitudinal and the outer - circular. The circular layer of muscles in the initial part of the urethra forms the voluntary internal urethral sphincter, m. sphincter urethrae intemus. In the membranous part, the urethra is limited by the muscle - the urethral closure, m. sphinter urethrae, which is a voluntary sphincter of the urethra.
Topography of the male urethra
The male urethra is located in the pelvic cavity and in the spongy substance of the penis. The prostatic part of the urethra is limited on all sides by the prostate gland. The membranous part passes through the urogenital diaphragm. Adjacent to its posterior surface is the bulbourethral gland, gl. bulbourethralis (Cowperi).X-ray anatomy of the male urethra. When the urethra is full contrast agent it has the appearance of a tube, on which its narrowing is visible.
Blood supply The male urethra is carried out by the branches of the inferior vesical arteries, the arteries of the bulb of the male penis and the arteries of the urethra. The veins of the canal form the venous plexus. Venous outflow is carried out into the vesical and perineal veins.
Lymph drainage carried out from the prostatic and membranous parts of the canal to the internal iliac, and from the spongy part to the inguinal lymph nodes.
Innervation The male urethra is carried out by branches, nn. penis and n. dorsalis penis. as well as plexus prostaticus.
The urethra (urethra) is designed to periodically remove urine from the bladder and expel semen (in men).
Male urethra is a soft elastic tube 16-20 cm long. It originates from the internal opening of the bladder and reaches the external opening of the urethra, which is located on the head of the penis.
The male urethra is divided into three parts: prostatic, membranous and spongy. Prostatic part is located inside the prostate and has a length of about 3 cm. On its posterior wall there is a longitudinal elevation - the ridge of the urethra. The most prominent part of this ridge is called seminiferous mound or spermatic tubercle, at the top of which there is a small depression - prostatic uterus. On the sides of the prostatic uterus, the openings of the ejaculatory ducts, as well as the openings of the excretory ducts of the prostate gland, open.
Membranous part starts from the apex of the prostate gland and reaches the bulb of the penis; its length is 1.5 cm. At this point the canal passes through the urogenital diaphragm, where around it due to concentric bundles of striated muscle fibers an arbitrary urethral sphincter.
Spongy part - the longest (about 15 cm) part of the urethra, which runs inside the corpus spongiosum of the penis.
Mucous membrane The prostatic and membranous parts of the canal are lined with multilayer cylindrical epithelium, the spongy part with single-layer cylindrical epithelium, and in the area of the glans penis with multilayer squamous epithelium.
The female urethra is wider than the male urethra and much shorter; it is a tube 3.0-3.5 cm long, 8-12 mm wide, opening into the vestibule of the vagina. Its function is to excrete urine.
In both men and women, when the urethra passes through the urogenital diaphragm, there is an external sphincter, which is subject to the human consciousness. The internal (involuntary) sphincter is located around the internal opening of the urethra and is formed by a circular muscle layer.
Mucous membrane The female urethra has longitudinal folds and depressions on the surface - lacunae of the urethra, and the glands of the urethra are located in the thickness of the mucous membrane. The fold on the posterior wall of the urethra is especially developed. Muscularis consists of outer circular and inner longitudinal layers.
Kidney physiology
Urine formation consists of three processes: filtration, reabsorption (reabsorption) and tubular secretion.
The formation of urine in the kidney begins with ultrafiltration of blood plasma at the point of contact of the vascular glomerulus and the nephron capsule (Bowman's capsule, Shumlyansky-Bowman's capsule) as a result of the difference in blood pressure. From the capillaries of the glomerulus, water, salts, glucose and other blood components enter the capsule cavity. This is how the glomerular filtrate is formed (it lacks blood cells and proteins). About 1200 ml of blood passes through the kidney in 1 minute, which is 25% of all blood ejected by the heart. The transition of fluid from the glomerulus to the capsule in 1 minute is called speed glomerular filtration. Normally, in men, the glomerular filtration rate in both kidneys is 125 ml/min, in women - 110 ml/min, or 150-180 liters per day. This primary urine.
From the capsule, primary urine enters the convoluted tubules, where the process occurs reabsorption(reabsorption) of liquid and the components contained in it (glucose, salts, etc.). Thus, in the human kidneys, out of every 125 liters of filtrate, 124 liters are absorbed back. As a result, from 180 liters of primary urine, only 1.5-1.8 liters of final urine are formed. Some metabolic end products (creatinine, uric acid, sulfates) are poorly absorbed and penetrate from the lumen of the tubule into the surrounding capillaries by diffusion. In addition, cells renal tubules as a result of active transfer, a sufficient amount of unnecessary substances is removed from the blood into the filtrate. This process is called tubular secretion and is the only way to concentrate urine. A fall blood pressure may lead to cessation of filtration and urine production.
Regulation of urine formation carried out by the neurohumoral route. Nervous system and hormones regulate the lumen renal vessels, maintain up to a certain value blood pressure, contribute to normal urine formation.
Pituitary hormones have a direct effect on urine formation. Somatotropic and thyroid-stimulating hormones increase diuresis, and antidiuretic hormone reduces urine formation (stimulates the process of reabsorption in the tubules). Insufficient amounts of antidiuretic hormone cause diabetes insipidus.
The act of urination is a complex reflex process and occurs periodically. In a full bladder, urine puts pressure on its walls and irritates the mechanoreceptors of the mucous membrane. The resulting impulses along the afferent nerves enter the brain, from which impulses along the efferent nerves return to the muscular layer of the bladder and its sphincter; When the muscles of the bladder contract, urine is released through the urethra.
The reflex center for urination is located at the level of the II and IV sacral segments of the spinal cord and is influenced by the overlying parts of the brain - inhibitory influences come from the cerebral cortex and midbrain, excitatory influences come from the pons and posterior hypothalamus. Cortical influences, which provide an impulse for the voluntary act of urination, cause contraction of the muscles of the bladder, and internal pressure in it increases. The neck of the bladder opens, the posterior urethra widens and shortens, and the sphincter relaxes. Due to the contraction of the muscles of the bladder, the pressure in it increases, and in the urethra decreases, which causes the bladder to enter the emptying phase and remove urine out through the urethra.
Daily amount of urine (diuresis) in an adult, the normal level is 1.2-1.8 liters and depends on the fluid entering the body, ambient temperature and other factors. The color of normal urine is straw yellow and most often depends on its relative density. The urine reaction is slightly acidic, the relative density is 1.010-1.025. Urine contains 95% water, 5% solids, the main part of which is urea - 2%, uric acid - 0.05%, creatinine - 0.075%. Daily urine contains about 25-30 g of urea and 15-25 g of inorganic salts, as well as sodium and potassium salts. Only traces of glucose are found in the urine.
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