How Does the Urinary System Work?
Your body takes
nutrients from food and uses them to maintain all bodily functions including
energy and self-repair. After your body has taken what it needs from the food,
waste products are left behind in the blood and in the bowel. The urinary
system works with the lungs, skin, and intestines-all of which also excrete
wastes-to keep the chemicals and water in your body balanced. Adults eliminate
about a quart and a half of urine each day. The amount depends on many factors,
especially the amounts of fluid and food a person consumes and how much fluid
is lost through sweat and breathing. Certain types of medications can also
affect the amount of urine eliminated.
The urinary system
removes a type of waste called urea from your blood. Urea is produced when
foods containing protein, such as meat, poultry, and certain vegetables, are
broken down in the body. Urea is carried in the bloodstream to the kidneys.
The kidneys are
bean-shaped organs about the size of your fists. They are near the middle of
the back, just below the rib cage. The kidneys remove urea from the blood
through tiny filtering units called nephrons. Each nephron consists of a ball
formed of small blood capillaries, called a glomerulus, and a small tube called
a renal tubule. Urea, together with water and other waste substances, forms the
urine as it passes through the nephrons and down the renal tubules of the
kidney.
From the kidneys,
urine travels down two thin tubes called ureters to the bladder. The ureters
are about 8 to 10 inches long. Muscles in the ureter walls constantly tighten
and relax to force urine downward away from the kidneys. If urine is allowed to
stand still, or back up, a kidney infection can develop. Small amounts of urine
are emptied into the bladder from the ureters about every 10 to 15 seconds.
The bladder is a
hollow muscular organ shaped like a balloon. It sits in your pelvis and is held
in place by ligaments attached to other organs and the pelvic bones. The
bladder stores urine until you are ready to go to the bathroom to empty it. It
swells into a round shape when it is full and gets smaller when empty. If the
urinary system is healthy, the bladder can hold up to 16 ounces (2 cups) of
urine comfortably for 2 to 5 hours.
Circular muscles
called sphincters help keep urine from leaking. The sphincter muscles close
tightly like a rubber band around the opening of the bladder into the urethra,
the tube that allows urine to pass outside the body.
Nerves in the
bladder tell you when it is time to urinate, or empty your bladder. As the
bladder first fills with urine, you may notice a feeling that you need to
urinate. The sensation to urinate becomes stronger as the bladder continues to
fill and reaches its limit. At that point, nerves from the bladder send a
message to the brain that the bladder is full, and your urge to empty your
bladder intensifies.
When you urinate,
the brain signals the bladder muscles to tighten, squeezing urine out of the
bladder. At the same time, the brain signals the sphincter muscles to relax. As
these muscles relax, urine exits the bladder through the urethra. When all the
signals occur in the correct order, normal urination occurs.
Andropause related urinary problems
Men do experience different urinary problems as they age. While
some urinary problems have causes generally unrelated to hormones, a number of
the more common urinary problems such as Benign Prostatic Hyperplasia (BPH),
Interstitial Cystitis (IC -- commonly referred to as Painful Bladder Syndrome)
and urinary incontinence appear to have hormonal causes or contributors.
Benign Prostatic Hyperplasia
Benign Prostatic Hyperplasia (BPH) is an enlargement of the prostate gland. Prostate
enlargement squeezes the urethra, impeding the flow of urine and making
urination difficult or, sometimes, impossible. While BPH is common especially in men over the
age of 60, it does not always cause blockages. For those with benign prostatic
hyperplasia, other urinary problems in men like frequent
urination are common. Severe Benign Prostatic Hyperplasia (BPH) can lead
to kidney stones.
Growth of the prostate is influenced by hormones including
testosterone, estrogen and dihydrotestosterone (DHT), a hormone closely related
to testosterone. The results of the multiple researches are conclusive. Testosterone
levels almost always decrease during andropause. At the same time that
testosterone levels are declining, estrogen levels tend to be on the increase.
One way men produce estrogen is by using the enzyme aromatase to convert
testosterone to estrogen, using
an enzyme called aromatase. Aromatase levels commonly increase in men as
they age, resulting in increased estrogen production and decreased testosterone
in the body.
These hormonal changes as men age have been associated with
Benign Prostatic Hyperplasia (BPH), and balanced levels of estrogen, testosterone
and DHT can effectively reduce or eliminate BPH.
Kidney Stones
Kidney stones is the term commonly used to refer to
stones, or calculi, in the urinary system. Stones form in the kidneys and may
be found anywhere in the urinary system. They vary in size. Some stones cause
great pain while others cause very little. The aim of treatment is to remove
the stones, prevent infection, and prevent recurrence. Both nonsurgical and
surgical treatments are used. Kidney stones affect men more often than women.
Interstitial Cystitis (Painful Bladder Syndrome)
Painful Bladder
Syndrome (Interstitial Cystitis - IC) is a disorder in which the wall of
the bladder becomes inflamed, leading to a variety of urinary problems. The
consequences of Interstitial Cystitis can include thickening and scaring of the
walls of the bladder; diminished bladder capacity resulting in the need for
frequent urination; bleeding; and ulcers in the bladder lining.
The cause of Interstitial Cystitis is not fully understood,
but there are studies which seem to indicate a relationship between low
testosterone levels and Painful Bladder Syndrome in men. In these studies men
with IC were found to disproportionately show diminished levels of
testosterone. When treated with testosterone hormone replacement therapy some
men enjoyed relief from symptoms of Painful Bladder Syndrome.
Urinary incontinence in men
Male urinary incontinence is a loss of bladder control that causes the unintentional
passage of urine. Urinary incontinence is a component of a wide range of male
health issues, and urinary incontinence in men can have a wide range of causes.
Incontinence can
often be helped without medicine or surgery. The squeeze-and-hold exercises
known as Kegel's can decrease incontinence symptoms by strengthening the
muscles used to stop urination. These exercises are often combined with
biofeedback and a type of behavior modification known as bladder retraining.
Diet changes, smoking cessation and cutting back on caffeine and alcohol can
also be helpful.
While the most frequent male urinary problems, related to
the andropause, or caused by hormonal misbalance, were presented above, there
are multiple other health issues, which have other common sources and origins.
Brief overview is provided below.
Bladder Cancer
A disease of elderly adults, bladder cancer occurs in adults
older than 60 years in 70% of cases. Ninety percent of bladder cancer in the
United States is transitional cell carcinoma. Cigarette smoking is the single
greatest risk factor, and tobacco cessation has been shown to decrease the
risk. Occupational exposure to aromatic amines, such as aniline dyes, is also
an established risk factor.
Prostatitis
Prostatitis is inflammation of the prostate gland
that results in urinary frequency and urgency, burning or painful urination, a
condition called dysuria, and pain in the lower back and genital area, among
other symptoms. In some cases, prostatitis is caused by bacterial infection and
can be treated with antibiotics. But the more common forms of prostatitis are
not associated with any known infecting organism. Antibiotics are often
ineffective in treating the nonbacterial forms of prostatitis.
Proteinuria
Proteinuria is the presence of abnormal amounts of
protein in the urine. Healthy kidneys take wastes out of the blood but leave in
protein. Protein in the urine does not cause a problem by itself. But it may be
a sign that your kidneys are not working properly.
Renal Failure
Renal (kidney) failure results when the kidneys are not
able to regulate water and chemicals in the body or remove waste products from
your blood. Acute renal failure (ARF) is the sudden onset of kidney failure.
This condition can be caused by an accident that injures the kidneys, loss of a
lot of blood, or some drugs or poisons. ARF may lead to permanent loss of
kidney function. But if the kidneys are not seriously damaged, they may
recover. Chronic kidney disease (CKD) is the gradual reduction of kidney
function that may lead to permanent kidney failure, or end-stage renal disease
(ESRD). You may go several years without knowing you have CKD.
Urinary Tract Infections
Urinary tract infections (UTIs) are caused by
bacteria in the urinary tract. Women get UTIs more often than men. UTIs are
treated with antibiotics. Drinking lots of fluids also helps by flushing out
the bacteria.
The name of the UTI depends on its location in the urinary
tract. An infection in the bladder is called cystitis. If the infection is in
one or both of the kidneys, the infection is called pyelonephritis. This type
of UTI can cause serious damage to the kidneys if it is not adequately treated.
Urinary Retention
Urinary retention, or bladder-emptying problems, is a
common urological problem with many possible causes. Normally, urination can be
initiated voluntarily and the bladder empties completely. Urinary retention is
the abnormal holding of urine in the bladder. Acute urinary retention is the
sudden inability to urinate, causing pain and discomfort. Causes can include an
obstruction in the urinary system, stress, or neurologic problems. Chronic
urinary retention refers to the persistent presence of urine left in the
bladder after incomplete emptying. Common causes of chronic urinary retention
are bladder muscle failure, nerve damage, or obstructions in the urinary tract.
Treatment for urinary retention depends on the cause.
Sources and Additional
Information:
