URINARY SYSTEM

Urinary System

The urinary system includes several major and minor organs: the bladder, two kidneys, two ureters (these are tubes which lead from the kidneys to the bladder), and the urethra - this is a tube which leads from the bladder to the exterior of the body. The urinary tract is a little like a plumbing system, with special pipes that allow water, salts, and other waste products to flow through them. The kidneys are a sort of filter system for the blood. They reabsorb nearly 99% of the fluid which moves through them back into the blood, and send just two to four pints of waste (or urine) to the bladder, where it is stored until the body is ready to dispose of it. The kidneys permit the blood to keep glucose, salts and vital minerals after removing the waste products and other dangerous compounds; these are then passed out through the ureters to the bladder and are expelled in urine. The urine is produced in the kidneys; it trickles down twenty-four hours a day through two long tubes called ureters - these are between ten and twelve inches long, and they connect the kidneys to the bladder. The ureters are around one quarter of an inch in diameter. Their muscular walls contract, which creates a wave motion that forces the urine down into the bladder. Each ureter enters the bladder through a tunnel in the bladder wall, which is angled to prevent the urine from running back into the ureter when the bladder contracts. The bladder expands, and stores the urine until it can be eliminated. The tube through which the urine flows from the body is called the urethra.

Disorders

Your health very much depends on your urinary system functioning well. Waste products build up in the body when this system fails to function. Serious disorders, and even death, may result. Please consult your doctor immediately if you have any of the symptoms of the disorders discussed in this article.

Nephritis is the inflammation of the nephrons of the kidney, often called Bright's disease. It can be caused by most anything that irritates the kidneys, such as exposure to turpentine, bichloride of mercy, or even exposure to a cold. Bright's disease may follow very mild throat infections, so it is wise always to avoid fatigue or chilling, or anything that lowers resistance to colds. Toxins also cause nephritis, such as from scarlet fever, tonsillitis, alcohol, or measles. There are two kinds of nephritis: acute and chronic. In acute nephritis, the symptoms vary, but generally they involve dropsy in the ankles and eyelids, presence of albumin in the urine, suppression of urine, and sometimes convulsions. In most cases, there is no damage to the kidneys or other body parts, but in very severe cases death can result. When the kidneys suffer permanent damage, nephritis is chronic.

The symptoms of the chronic type of nephritis are somewhat the same as the acute type because there is almost always dropsy in the legs and eyelids. The urine becomes suppressed, complexion becomes pale, skin becomes puffy, and there is a possibility of complete urine suppression. The blood vessels supplying the nephrons of the kidney tissue can harden making it hard to force blood through the kidneys and resulting in a decrease in urine. Much can be done to slow down the progress of chronic nephritis.

Pyelonephritis is generally called "pelvis nephritis" and refers to inflammation of the renal pelvis and connective tissues of the kidney. As with cystitis, pyelonephritis is usually caused by bacterial infection but can also result from viral infection, mycosis, calculi, tumors, pregnancy, and other conditions. Acute pyelonephritis develops rapidly and is characterized by chills, fever, pain in the sides (flank), nausea, and an urge to urinate frequently. This often is the result of the spread of infection from the lower urinary tract or through the blood from other organs. Chronic pyelonephritis is thought to be caused by an autoimmune disease but is often preceded by a bacterial infection or urinary blockage.

Cystitis is an inflammation of the bladder and most often occurs because of an infection when bacteria enters the bladder through the urethra. Women are known to have this condition more than men because the female urethra is shorter and closer to the anus than the male's and is a source of bacteria. Symptoms of cystitis are persistent frequency of urination and also suprapublic pain. The inflammations of the bladder may be characterized by pelvic pan, an urge to urinate frequently, and also hematuria. Urethral syndrome and interstitial cystitis are two common forms of this inflammation and are "nonbacterial" forms. Interstitial is an autoimmune disease of the bladder, and urethral syndrome occurs most in young women but develops into a bacterial infection.

Urethritis is an inflammation of the urethra that results most of the time from a bacterial infection, often from gonorrhea. Males, especially infant males, suffer from urethritis more than females. It is an infection of the urethra, the pathway for urine and semen. Symptoms are pain, a burning sensation during urination or erection, and a discharge from the urethral opening on the tip of the penis. Most cases of urethritis can be treated with antibiotics. This is easily transmitted from one partner to another sexually.

Urinary tract infection

A urinary tract infection (UTI) is a bacterial infection that affects part of the urinary tract. When it affects the lower urinary tract it is known as a simple cystitis (a bladder infection) and when it affects the upper urinary tract it is known as pyelonephritis (a kidney infection). Symptoms from a lower urinary tract include painful urination and either frequent urination or urge to urinate (or both), while those of pyelonephritis include fever and flank pain in addition to the symptoms of a lower UTI. In the elderly and the very young, symptoms may be vague or non specific. The main causal agent of both types is Escherichia coli, however other bacteria, viruses or fungi may rarely be the cause.

Urinary tract infections occur more commonly in women than men, with half of women having at least one infection at some point in their lives. Recurrences are common. Risk factors include female anatomy, sexual intercourse and family history. Pyelonephritis, if it occurs, usually follows a bladder infection but may also result from a blood borne infection. Diagnosis in young healthy women can be based on symptoms alone. In those with vague symptoms, diagnosis can be difficult because bacteria may be present without there being an infection. In complicated cases or if treatment has failed, a urine culture may be useful. In those with frequent infections, low dose antibiotics may be taken as a preventative measure.

In uncomplicated cases, urinary tract infections are easily treated with a short course of antibiotics, although resistance to many of the antibiotics used to treat this condition is increasing. In complicated cases, longer course or intravenous antibiotics may be needed, and if symptoms have not improved in two or three days, further diagnostic testing is needed. In women, urinary tract infections are the most common form of bacterial infection with 10% developing urinary tract infections yearly.

Nephrotic syndrome

Nephrotic syndrome is a group of symptoms that include protein in the urine, low blood protein levels, high cholesterol levels, high triglyceride levels, and swelling.

Causes

Nephrotic syndrome is caused by different disorders that damage the kidneys. This damage leads to the release of too much protein in the urine.

The most common cause in children is minimal change disease. Membranous glomerulonephritis is the most common cause in adults.

This condition can also occur from:

• Cancer
• Diseases such as diabetes, systemic lupus erythematosus, multiple myeloma, and amyloidosis
• Genetic disorders
• Immune disorders
• Infections (such as strep throat, hepatitis, or mononucleosis)
• Use of certain drugs

It can occur with kidney disorders such as:

• Focal and segmental glomerulosclerosis
• Glomerulonephritis
• Mesangiocapillary glomerulonephritis

Nephrotic syndrome can affect all age groups. In children, it is most common between ages 2 and 6. This disorder occurs slightly more often in males than females.

Symptoms

Swelling (edema) is the most common symptom. It may occur:

• In the face and around the eyes (facial swelling)
• In the arms and legs, especially in the feet and ankles
• In the belly area (swollen abdomen)

Other symptoms include:

• Foamy appearance of the urine
• Poor appetite
• Weight gain (unintentional) from fluid retention

Treatment

The goals of treatment are to relieve symptoms, prevent complications, and delay kidney damage. To control nephrotic syndrome, you must treat the disorder that is causing it. You may need treatment for life.

Treatments:

• Keep blood pressure at or below 130/80 mmHg to delay kidney damage. Angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) are the medicines most often used. ACE inhibitors may also help decrease the amount of protein lost in the urine.
• You may take corticosteroids and other drugs that suppress or quiet the immune system.
• Treat high cholesterol to reduce the risk of heart and blood vessel problems. A low-fat, low-cholesterol diet is usually not very helpful for people with nephrotic syndrome. Medications to reduce cholesterol and triglycerides (usually statins) may be needed.
• A low-salt diet may help with swelling in the hands and legs. Water pills (diuretics) may also help with this problem.
• Low-protein diets may be helpful. Your health care provider may suggest eating a moderate-protein diet (1 gram of protein per kilogram of body weight per day).
• You may need vitamin D supplements if nephrotic syndrome is long-term and not responding to treatment.
• Blood thinners may be needed to treat or prevent blood clots.

The outcome varies. The condition may be acute and short-term or chronic and not respond to treatment. The complications that occur can also affect the outcome.

Some people may eventually need dialysis and a kidney transplant.

Bladder

The urinary bladder is the organ that collects urine excreted by the kidneys before disposal by urination. A hollow muscular, and distensible (or elastic) organ, the bladder sits on the pelvic floor. Urine enters the bladder via the ureters and exits via the urethra.

Bladders occur throughout much of the animal kingdom, but are very diverse in form and in some cases are not homologous with the urinary bladder in humans.

The human urinary bladder is derived in embryo from the urogenital sinus and, it is initially continuous with the allantois. In males, the base of the bladder lies between the rectum and the pubic symphysis. It is superior to the prostate, and separated from the rectum by the rectovesical excavation. In females, the bladder sits inferior to the uterus and anterior to the vagina; thus, its maximum capacity is lower than in males. It is separated from the uterus by the vesicouterine excavation. In infants and young children, the urinary bladder is in the abdomen even when empty