Tag Archives: bladder

The Urinary System

What Does The Urinary System Do?

The urinary system eliminates waste from the body, in the form of urine.

The kidneys remove waste from the blood. The waste combines with water to form urine. From the kidneys, urine travels down two thin tubes called ureters to the bladder. When the bladder is full, urine is discharged through the urethra.

Urinary System

What Makes Up The Urinary System?

Kidneys

A pair of purplish-brown organs located below the ribs toward the middle of the back. Their function is to remove liquid waste from the blood in the form of urine; keep a stable balance of salts and other substances in the blood; and produce erythropoietin, a hormone that aids the formation of red blood cells.

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.

Ureters

Narrow tubes that carry urine from the kidneys to the bladder. Muscles in the ureter walls continually tighten and relax forcing urine downward, away from the kidneys. If urine backs up, or is allowed to stand still, a kidney infection can develop. About every 10 to 15 seconds, small amounts of urine are emptied into the bladder from the ureters.

Bladder

A triangle-shaped, hollow organ located in the lower abdomen. It is held in place by ligaments that are attached to other organs and the pelvic bones. The bladder’s walls relax and expand to store urine, and contract and flatten to empty urine through the urethra. The typical healthy adult bladder can store up to two cups of urine for two to five hours.

Sphincter muscles

Circular muscles that help keep urine from leaking by closing tightly like a rubber band around the opening of the bladder.

Nerves in the bladder

These alert a person when it is time to urinate, or empty the bladder.

Urethra

The tube that allows urine to pass outside the body. The brain signals the bladder muscles to tighten, which squeezes urine out of the bladder. At the same time, the brain signals the sphincter muscles to relax to let urine exit the bladder through the urethra. When all the signals occur in the correct order, normal urination occurs.

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.

5 Interesting Facts About The Urinary System

  1. Adults pass about a quart and a half of urine each day.

  2. The volume of urine formed at night is about half that formed in the daytime.

  3. Normal urine is sterile. It contains fluids, salts and waste products, but it is free of bacteria, viruses and fungi.

  4. In ancient Egypt and Ireland, women stood to urinate. It was the men who sat or squatted.

  5. Since urine contains large amounts of urea, it is an excellent source of nitrogen for plants and a good accelerator for compost.

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.

What Can Go Wrong With Your Urinary System?

Problems in the urinary system can be caused by aging, illness, or injury. They range in severity from easy to treat to life threatening. These are examples:

Benign Prostatic Hyperplasia (BPH)

BPH is a condition in men that affects the prostate gland, which is part of the male reproductive system. The prostate is located at the bottom of the bladder and surrounds the urethra. BPH is an enlargement of the prostate gland that can interfere with urinary function in older men. It causes blockage by squeezing the urethra, which can make it difficult to urinate. Men with BPH frequently have other bladder symptoms including an increase in frequency of bladder emptying both during the day and at night. Most men over age 60 have some BPH, but not all have problems with blockage. There are many different treatment options for BPH.

Painful Bladder Syndrome/Interstitial cystitis (PBS/IC)

PBS is a chronic bladder disorder also known as frequency-urgency-dysuria syndrome. In this disorder, the bladder wall can become inflamed and irritated. The inflammation can lead to scarring and stiffening of the bladder, decreased bladder capacity, pinpoint bleeding, and, in rare cases, ulcers in the bladder lining. The cause of IC is unknown at this time.

Kidney Stones

This 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.

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 (Kidney) Failure

Renal 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 (UTIs)

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 Incontinence

Urinary Incontinence, or loss of bladder control, is the involuntary passage of urine. There are many causes and types of incontinence, and many treatment options. Treatments range from simple exercises to surgery. Women are affected by urinary incontinence more often than men.

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.

How Do Your Keep Your Urinary System Healthy?

To keep your urinary system healthy, follow these tips . . .

  1. Drink water when you feel thirsty.

    When you urinate, you are eliminating waste products from your system. To keep your urine flowing normally and avoid blockages, be sure to drink when you are thirsty. The American Dietetic Association recommends eight 8oz. glasses per day.

  2. Go easy on the salt, which makes you retain water.

    Too much salt in your diet keeps the salt/mineral/water balance in your kidneys off kilter. A high-sodium diet has been associated with elevated blood pressure. Long-term, uncontrolled high blood pressure can lead to kidney damage. A high-salt diet may also contribute to the development of kidney stones. Paying attention to sodium labels on processed foods and reducing intake of canned soups and vegetables, luncheon meats, hot dogs, and sausages, may help you lower your risk for developing calcium-based kidney stones.

  3. Consider reducing your caffeine intake.

    Drinking caffeinated beverages may irritate your bladder and serve as a diuretic (increase your need to urinate). The more caffeine you drink, the more you may have to urinate.

This article is part of a series called “Your Body: An Owner’s Manual” which explains how your body systems work and how to maintain them. The first article in the series included a picture of my wife, fitness coach Kathie Lamir, who exemplifies a healthy body. Pictures of Kathie were so well received that I have included one with each article in the series

Fitness Authority Kathie Lamir

Shrinkage! How Our Body Parts Get Smaller As We Age

ShrinkageWhen I say “shrinkage,” what do you think of?

Many of you immediately thought of the Seinfeld episode where George Costanza was seen naked by Jerry’s girlfriend after he came out of the pool. He tried to explain his teeny weenie by claiming “shrinkage.”

Well, it turns out that’s just part of the story.

As we get older there’s plenty of shrinkage, including our height, heart, brain, bladder, facial bones and, yes, sex organs.

Height Shrinkage

Most of us lose at least 1/3 of an inch in height every decade after the age of 40.

By 80, most men will be 2 inches shorter than they were in their prime, and women will be as much as 3.15 inches shorter.

What causes this?

Beginning at about 35, our bones lose minerals, especially calcium. Because our body’s ability to grow new bone tissue slows, our bones shrink slightly (and become more brittle and more likely to collapse as well as more likely to break, a condition known as osteoporosis).

In addition, the discs between the bones of our spine flatten over time, also contributing to making us shorter.

Temporary Height Shrinkage: Did you know that our discs temporarily flatten daily as we stand and move around? When we lie down at night, the discs reabsorb fluid and return to normal. That’s why we shrink by as much as ½ inch during the day but regain the height over night.

What can you do to protect yourself against height shrinkage?

First, choose the right parents. Not everyone get shorter, or shortens as much. There is a definite hereditary component.

Beyond that, a healthy lifestyle is your best protection.

Research has shown that people who engaged in moderately vigorous aerobic activity lost only about half as much height as those who stopped exercising in middle age or never exercised at all.

To help stave off osteoporosis, you should stick to a healthy diet with adequate calcium and vitamin D.

Smoking, alcohol and excess caffeine (more than eight cups of coffee or tea a day) can affect bone health, too.

Maintaining good posture will also protect ageing discs.

Heart Shrinkage

Our heart shrinks by an average 0.3 grams per year beginning in middle age.

According to researchers at Johns Hopkins University, with every year it takes longer for the heart muscles to squeeze and relax, by around 2 to 5 %, and the amount of blood pumped out of the heart falls by 9 millilitres a year.

A poor blood supply leaves you more prone to heart failure.

How do you protect yourself against the effects of a shrinking heart?

Like all muscles, the heart becomes stronger and less likely to shrink if it is exercised.

Exercises that benefit your heart include walking, climbing stairs, gardening, vigorous housework, dancing or using home or gym exercise equipment.

Brain Shrinkage

Starting around the age of 20, your brain shrinks by as much as 10 to 15 % over your lifetime.

Doctors don’t know why this is, but studies show the process appears to be accelerated by smoking, drinking alcohol and diabetes.

Being overweight and having high cholesterol levels also appear to have an impact.

Scans show the frontal and temporal lobes (which control thinking, planning and memory) shrink most.

However, contrary to expectation, the shrinkage doesn’t necessarily affect our thinking capacity, and cognitive tests have shown men and women perform similarly despite increasingly different brain sizes.

Can we protect against brain shrinkage?

Keeping mentally active throughout your life is key.

Avoiding excess alcohol also helps (post-mortems show alcoholics have smaller, shrunken brains), as does getting adequate sleep.

Bladder Shrinkage

At the age of 25, the average person’s bladder can hold 2 cups of liquid, but by 65 its capacity is half that.

Capacity and function shrink with age because of physiological changes to the muscle structure.

Is bladder shrinkage inevitable?

Avoid excess caffeine or alcohol because they irritate the bladder.

Men and women should also do regular pelvic floor exercises to boost bladder control.

Facial Bone Shrinkage

Scientists used to think loss of muscle tone and gravity led to facial ageing, but more recent thinking is that the facial bones actually shrink in size, sucking in the skin and muscle around them.

The jawbone is most prone to shrinkage.

Experts believe women lose facial bone structure earlier than men (women in their early 40s, men 10 to 15 years later).

Is there any hope of avoiding or slowing facial bone shrinkage?

The key is to practice good dental hygiene to prevent tooth decay and loss which can aggravate the process.

Sex Organ Shrinkage

Both male and female sexual organs shrink with age.

With men this occurs for two reasons.

First, fatty substances (plaques) are deposited inside tiny arteries in the penis, restricting blood flow. This poor circulation leads to ‘atrophy’ of the tissue within the penis — leading to loss of length and thickness.

Second, there is a gradual build-up of relatively inelastic collagen (scar tissue) within the stretchy, fibrous sheath that makes erections possible.

If a man’s erect penis is 6 inches long when he is in his 30s, it might be 5 inches or 5½ inches when he reaches his 60s or 70s.

In addition, beginning around the age of 40, the testicles begin to shrink, by up to a 1/3 inch in diameter between the ages of 30 and 60.

In women, changes are related to reduced levels of estrogen, which reduce blood flow to the area. The uterus also shrinks, returning to the size of a pre-adolescent girl, as the body registers that the organ is no longer active and so spares vital resources that other, still active organs can use.

Dwindling estrogen levels mean mammary glands and milk-producing tissue wither, to be replaced by fat, so the breasts lose their bulk. Natural wear-and-tear on the supporting skin and ligaments makes them more likely to drop.

Is there anything you can do to protect against sex organ shrinkage?

For men, a healthy diet that is good for your heart will also be good for your sex life — as healthy arteries all over your body mean better blood flow to the penis.

Women can do little about breast changes (apart from wear a well-fitting bra), but for both men and women, regular sex can slow the shrinking process.

Largely, it’s a case of use it or lose it.

These Body Parts Don’t Shrink, They Keep Growing!

While all this shrinking is going on, our nose, ears and feet keep growing.

The inner part of the ear lobe (the ‘concha’) remains the same size, but most ears become steadily longer.

The traditional explanation has been they are made up cartilage, which continues to grow after bones.

However, gravity is another factor. Cartilage, like skin, becomes thinner and loses its elasticity as we age, with collagen and elastin fibres breaking down.

This allows skin to stretch and sag, the tip of the nose to lengthen and droop, and the ears to stretch down.

Our feet become longer and wider with age, as the tendons and ligaments which link the many tiny bones lose elasticity.

Podiatrists estimate that the over-40s can gain as much as one shoe size every ten years.

The tiny joints between the toe bones deteriorate, allowing the toes to spread out, and the arch of the foot to flatten.

The protective fat pads on the heels and balls of the feet also flatten through wear and tear.

What’s the take-away from all this? Eat right and exercise regularly to put the most life in your years.