Urinary System


The purpose of this course is to instruct the student on the basic anatomy and physiology of the urinary system, disorders of, changes in aging, nursing assessment and treatments.


Upon completion of this course, the student should be able to:

  1. The student will be able to identify and describe the basic parts of the urinary system and how they relate to her nursing care..
  2. The student will be able to explain in l the functions of the urinary system and importance of proper function related to the nursing role..
  3. The student will be able to verbalize the common disorders of urinary systems and the effects they have to the patient.
  4. The student will have the knowledge and be able to identify the signs and symptoms associated with urinary disorders/disease and the nurses role in each.
  5. The student will have knowledge of currant treatments and tests used for urinary disorders and their responsibilities in relationship to them.


The urinary system is a group of organs that produce and excrete urine from the body.

Urine is a transparent yellow fluid containing unwanted waste products, mostly water, salts and nitrogen. Urine is slightly acidic and has a pH of 4.6 to 8.0. Abnormal findings would be keytone bodies, pus, blood, bacteria, glucose and certain crystals.

The major organs of the urinary system are the kidneys; a pair of bean-shaped organs that filter out substances that are contained in the blood. The entire bodies blood supply which is approximately 7-8% of the persons body weight; filters through these bean-shaped organs every thirty seconds, this produces what we call urine. Urine flows from the kidneys through two long, thin tubes called ureters. With a constant wave like action the urine moves itself along a provided path. The ureters transport the urine to the bladder, a very large vascular muscular organ. The bladder can store large amounts of urine, which excrete through a tube shaped urethra, to the outer meatus, (opening of the body); and is held inside the body by a elastic ring like muscle called the urinary sphincter muscle, which allows for spontaneous emptying.

An average adult produces approximately 1.5 liters of urine each day; the body needs this much at a minimum to avoid dehydration. The body needs to excrete approximately .5 liters daily to rid it self of unwanted waste.

Excessive or inadequate production of urine may indicate illness and a urinalysis or twenty-four urine may be ordered to determine the cause.

The presence of glucose, or blood sugar, in the urine may be a sign of diabetes; bacteria in the urine signal an infection of the urinary system; and red blood cells in the urine may indicate cancer or other disease processes in the urinary tract.


The kidneys are embedded in the dorsal portion of the abdomen. They are found in the fat tissue on either side of the back bone, the right kidney is slightly lower then the left, they both fall in at about waist level. The kidneys are reddish-brown in color. Each kidney is approximately 11cm long, 6 cm wide and 2 1/2 cm thick, each weighing in at 140 to 160 grams (5-6 oz) and as stated earlier are shaped like a kidney bean (hence the name).

On the inner border of the kidneys lies a border, or a depression called a hilum, this is where the renal artery, the renal vein, and the ureter connect with the kidney.

There are over 1700 liters (450 gal) of blood passing through the renal artery to the kidneys every day. The kidneys filter the blood and return it to the heart via the renal vein. The kidneys specialized tissue function to maintain balance, (homeostasis). The kidneys actually determine the water and chemical composition of the blood, which in turn determines the content of the tissue fluid that surrounds the cell.

Each kidney works as a complex filtration network and reabsorption system. Each kidney consists of more then 2 million coiled channels called nephrons, which perform this critical blood-filtering function and produce urine in the process.

The top of the nephron is shaped like a cup and is called the Bowmens capsule, it surrounds a cluster of capillaries (the smallest blood vessel) called a glomerulus. Blood flows into each of the glomerulus by way of arterioles, (the smaller end of an artery), these run down long the descending and ascending tubes; these tubes merge into the kidney pelvis, a funnel- shaped area at center of the kidney.

The upper portion of the kidney is bulblike and filters water, urea (the nitrogen-containing breakdown product of protein), salts, glucose, amino acids, (the bodyís building blocks of protein), yellow bile (compounds formed from the liver), and other trace elements from the blood.

As this material moves through the glomerulus many of these filtered materials are reabsorbed into the blood to be reused by the body. They help maintain the normal body functions. Less then 1% of the water and other materials remain behind to be secreted as waste/urine.

These waste materials then pass from the nephrons into the renal pelvis. From the renal pelvis, waste seeps out of the kidney into the ureter. The ureter is a tube that comes from each kidney down into the bladder. The ureter is approximately 25 to 30 cm (10 to 12 in) long and about .5 cm in diameter. The ureter empties into a hollow, muscular sac called the urinary bladder. There is a flap of tissue at the point where the ureter meets the bladder it acts as a valve to prevent the back flow of urine.

The urinary bladder is able to expand and contract according to how much urine it has in it. As the bladder fills with urine the walls become thinner, they can stretch to the size of 12.5 cm. (5in), or more.

As the bladder becomes full, receptors that are sensitive to pulling/stretching become stimulated and you know it is time to empty your bladder. When the person is ready to void the urine the sphincter muscle relaxes and urine is able to leave the body through the urethra. The urethra is a tube leading from the bladder to the outside of the body. It is 3.8cm (1 1/2 in) in the female and is strictly used for urinary output. In the male the urethra is approximately 20cm (8 in) long; it passes through the penis to excrete the urine and also serves as a passage way for semen during intercourse. When the penis is erect, the opening from the bladder cuts off blocking the probability of urine being passed on to the female.

The kidney is a very complex organ, they have three main functions

1.) To filter materials from the blood that are no longer needed, the body has in excess and then to return the useable products back into the blood system.

2.) To maintain water and electrolyte balance, ensuring that the amount of water in the body tissues remains at a constant level; IE; if a person drinks a lot of water one day, but a little water the next day, the kidneys are able to adapt by regulating the water balance in the tissues.

3.) To maintain acid base balance. In other words the function of the kidneys is to assist the body in maintaining homeostasis, which is the balance of blood and body fluids that is needed by the body to allow all processes to run smoothly. By controlling salt levels, the kidneys help regulate blood pressure.

These processes are vital and rely on normal functioning of the kidneys. If the kidneys are diseased so that they are not functioning, death will result. Each part of the urinary system has its own specialized function, but all of the parts must be working in unison for the whole system to work properly.

All vertebrates dispose of excess water and waste by means of kidneys. The kidneys of fish and amphibians are much simpler then mammals. Fish and amphibians absorb a great deal of water and, as a result must rid themselves of large quantities of urine. In comparison to the urinary system of a bird and reptile are designed to conserve water; these animals produce urine that is solid or semisolid.


Urologists are physicians who specialize in treating urinary disorders and diseases.

Renal failure is one of the most serious disorders found in this system. Renal failure can be total or partial either way it is very serious. Renal failure slows or stops the filtration of blood, causing toxic waste products to build up in the blood.

Lets look at the differences between acute and chronic renal failure.

Acute renal failure is characterized by a sudden occurrence, decreased amount of urinary output, (less then 500cc qd)(oliguria) and rapid accumulation of nitrogenic wastes in the blood (azotemia). Acute type of failure can come from hemorrhage, trauma, burn, and toxic injury to the kidneys, severe infections or blockage to the lower urinary track. Many forms of acute renal failure are reversible when the cause is corrected.

Chronic renal failure is a progressive deterioration of kidney function over a long period of time. Chronic renal failure may result from many diseases such as diabetes, lupus, AIDS, and myeloma. If caught early enough the degenerative process can be slowed but not reversed. Early signs include sluggishness, fatigue, and mental dullness; later this disorder can progress to zero urine output, (anuria), convulsions, GI bleed, malnutrition, and various neuropathies, and the skin will becomes yellow. CHF and hypertension are complications that occur from the hypervolemia associated with increased volume from no urinary output. Treatment is restricted water and protein intake, diuretics. When all else fails the patient must begin long term hemodialysis and many times kidney transplant.

Urinary calculi, commonly known as kidney stones, results from a gradual build up of crystallized salts and minerals in the urine, (many times related to calcium, uric acid). They be found anywhere from the kidney to the bladder and vary in size, from fine grains of sand to the size of an orange. Certain factors add to the formation of these stones, including infection, urinary stasis and periods of immobility and hypercalciuria (to much calcium in the urine). This is a more common occurrence in men in their 50ís. If you have had one stone your chances of getting another is increased.

Urinary calculi can be very painful, mostly if they obstruct a passageway that carries urine. Usually, the stones pass through and out of the urinary tract on their own, scratching there way along the interior line of whatever area they come into contact with. When a large stone finds it way down the urethra it can be extremely painful. If they fail to pass themselves through they can be broken up using an ultrasound method called lithotripsy.

Urinary tract infection, (UTI) is an infection of one or more of the structures in the urinary tract. Most UTIís happen from bowel organisms, (E-coli). Women are more prone to UTIís because of the shortness of their urethra.

Infections of the lower urinary tract are called cystitis. This is an inflammation of the urinary bladder, most often caused by ascending infection from the urethra; it can also be caused by sexual intercourse. Signs and symptoms of a lower UTI are; frequency of urination, urgency of urination, burning upon urination. The urinalysis may show bacteria, pus and red blood cells. Treatment of antibiotics, fluids, and educating the patient on possible causes helps to avoid future episodes. Some people are more prone to reoccurring UTIís.

Infections of the upper urinary tract are called pyelonephritis. This is an infection of renal pelvis, tubules, (tubes), in the kidneys. The bacteria may enter through the bladder via the ureters or through blood stream.

Many times this upper UTI is caused by reflux of urine up through the ureters from a faulty valve, that is suppose to prevent this from happening. Sign and symptoms are chills and fever; flank pain. A urinalysis will show bacteria, pus. The s/s are pretty much the same as for the lower UTI except the bacteria in the urine found on the urinalysis are coated with antibodies that happens only in the renal pelvis. An upper UTI is more serious due to the fact it can cause damage and death to tissues in the kidneys if not treated,

Kidney and bladder cancer has been on rise for the past thirty years. These cancers have been linked to various causative agents, primarily cigarette smoking, abuse analgesics, obesity and certain industrial chemicals. Treatment typically includes removal of cancer tissue, followed by radiation therapy.


There are many inherited and congenital disorders of the urinary system.

Polycystic renal disease is a disease of many cysts that formed in the kidneys, reducing the amount of functioning that the renal tissue can do. Kidney dialysis or transplant is most often needed to prevent kidney failure or even death. Hypospadias is a birth defect in which the male urinary opening is misplaced on the penis; it may be under the head of the penis or as far away as the scrotum. Surgery before the child reaches twenty-four months old can correct the defect, permitting normal urination and, later, sexual intercourse.


There are a number of age-related changes that effect the urinary system. As an individual age, the kidneys function less efficiently. A person eighty years old will have half the nephrons as that of a newborn baby. If only half the nephrons are there then the kidneys decrease at least that much in their ability to filter and function. For this reason, an elderly person is much more likely to have a drug reaction then a middle aged or young person would. The kidney is less efficient in removing the drug from the bloodstream.

Arteriosclerosis, (thickening & loss of elasticity to arterial wall, decreasing blood flow) can affect the blood vessels that supply the urinary system. When circulation is poor, there is a greater chance of developing infection as well as decreased ability to recover from illness or injury.

There are age-related changes that decrease the elasticity of the ureters, bladder, and urethra. As muscle tone decreases, the amount of urine the bladder can hold is reduced. Many times the elderly person will not be aware of the need to void until their bladder is almost full or full. This leads to:

* Frequency-- the need to urinate often

* Urgency-- an immediate need to urinate

* Nocturia-- waking at night to urinate

* Incontinence-- inability to hold urine

The first three of the above definitions lead to the fourth; incontinence. Incontinence can also come from certain medications, but whatever the reason it is a serious problem. It is a physical problem with the potential of the skin to breakdown from the exposure to acidic urine on the skin. Many rashes and pressure sores, (decubitis ulcers), come from a patient being incontinent.

Incontinence also as a large effect on the psychological aspect of the patient health. Incontinence is very distressing and embarrassing; if you can remember ever wetting your pants as a child you know what I am talking about. Patients with neurological disorders (related to the nervous system), frequently have no control of their bladder functions because the brain is unable to receive signals to control urination. Many times this leads a person with a neurological disorder to have a urinary catheter inserted (a tube that is inserted into the bladder to drain urine into a collection bag).

Urinary tract infections, (reviewed previously), are a common thing in many people in different age groups, however, the elderly when confined to bed, or when they have a catheter, or when they are incontinent of bowel, have an increased chance of getting a UTI.

Immobility has serious effects on the urinary system primarily because of the incomplete emptying of the urine from the bladder and kidneys. When urine is retained too long as with any fluid standing still, it begins to grow bacteria, resulting in infection and development of kidney stones (calculi).

Incomplete emptying of the bladder may be related to patient positioning when urinating. When a patient is confined to bed and has to use a bedpan their positioning is extremely important. When placing a patient on a bed pan make sure it is placed correctly under them, also the patient should be returned to a sitting position on the bed pan to make it has natural as possible. Keep the patient covered up with a call light in reach. Respect privacy.


One of the most important nursing roles involved in the urinary system is keeping I & O, (intake and output).

The fluid intake and output must be accurately measured for all patients with any urinary related issues. Unless a patient is on fluid restrictions they should be offered fluids frequently and have them fresh and readily available at their bedside. Fluids should include a variety of juices, tea, soups and most of all water. Adequate hydration keeps the urinary system clean and prevents urine from becoming concentrated. The fluid intake should be no less then 2500 cc every day. Unless fluids are being lost through excessive perspiration, vomiting or diarrhea the output should be approximately 2000 cc ( if their intake was 2500cc). There is always loss with breathing and normal body function. If the patient is dehydrated and not receiving enough fluids these body functions can not be performed correctly.

The intake part of I & O consists of any fluid taken in by the patient. This can be orally or IV. A fluid is anything that is liquid or turns back into liquid at room temperature. Ice cream, Jell-O, Soups. The output part of I & O is any thing out of the body in liquid form. This can be from any part of the body. Vomiting, severe perspiration, diarrhea, and of course urine. All of these must be written down and documented as soon as it occurs. Trying to remember what your patient drank all day or when and how much they urinated is not OK. Many patient are too confused or just to tired or confused to remember what they drank or how much they urinated.

If you have a mobile patient it is best to have a hat in the commode to catch the urine. For a man have him use a urinal. For things like excessive sweating this is more difficult to measure, you may say a chux soaked two times this shift.. This can also be used if the patient is incontinent and uses some sort of attends (adult diaper). Some people are on very strict I & O and the attends would have to be weighed. When doing I & O remember to notice the color and odor and any sentiment you may see.

Another nursing responsibility is collecting specimens related to the urinary system "A Urinalysis". There are several different kinds of urine samples that may be needed:

1.) Clean catch, all urine specimen should be clean catch, if a urine specimen states:

2.) Routine, this means there is no special procedures for collection but bacteria collects around the urinary meatus all the time, so if we do not clean the area prior to collection of the specimen you are going to end up with a contaminated specimen. So be it routine or clean catch, please clean the area prior to collection.

3.) Sterile urine specimen needs to come from a catheter. It is not OK to collect a specimen directly from a catheter bag!!! You must clamp the catheter off for approximately 20 - 30 minutes prior to collection and then clean the catheter tip with alcohol and then drip the urine into a sterile cup. If it is a patient who does not already have a catheter in place then you, (the license. nurse) must do a sterile straight catheter specimen.

4.) A 24 hour urine specimen is just that. You MUST save all urine for 24 hours to find out if there is protein being spilled into the urine. If any of the urine is not added to the specimen it is of no value and must be done all over again.

All urine specimens must be labeled with the patients name, time and date, they must also be refrigerated until they are given to the lab.


A nursing responsibility in any level of nursing is catheter care. No matter what level of nursing you do, there is a obligation to perform high levels of catheter care.

A Foley catheter is a sterile plastic tube that is inserted into the patientís urethra, once it goes into the urethra it is guided carefully up into the bladder. In the female this is approximately 1 1/2 inches, in the male approximately 8 inches. Once the sterile plastic tube has been placed and has urine return, (to ensure proper placement), a balloon that lies at the top of the catheter is inflated. There are two ports at the external portion of the catheter, one is to hook the closed drainage bag and the other is to insert 5-8 cc of sterile water to inflate the balloon. Once this balloon is inflated with water it is VERY painful to be pulled on. To give you a visual; look at your pinkie finger, suppose this was the size of your urinary meatus, now; pull a good size tangerine through a hole that size inside your body. Think that would HURT? There are leg straps to avoid this from happen, make sure the catheter is secure in some way to the patientís leg.

Once the catheter is in place and there has been a adequate urine return, the inflated balloon and leg strap with keep the catheter in place. There is a catheter bag that is attached to the open port. This bag is to stay on the catheter except for the BI-monthly changed, (each facility has their own rules for when the catheter and bags are changed). Infections (UTIís) are just waiting to get up into the urinary system, please do not help them. If a patient has a bowel movement, the catheter needs to be wiped down. This is a direct line for the e-coli to travel. There is no reason to remove a catheter bag for showering it is a closed system and it can get wet, this is actually a good time to make sure everything gets clean. The tubing must hang freely, no kinks or obstruction.

Always remember fluids run down hill, so the catheter bag must always be below the bladder or the urine will back flow into the bladder and this can cause infection. There are many reasons patients have Foley catheters and most people do not enjoy them. Please keep this in mind when dealing with the patient with a Foley catheter. Patients may complain of pain around the urinary meatus while there is a catheter in place, this may be caused by spasms and needs to be dealt with as soon as possible, it can be very painful and cause urinary retention.

Many times patients with catheters are on I &O. When draining the urinary catheter bag, ( which should be emptied at the end of each shift), you need to use a graduate that is marked allowing you to measure the output. Do not measure urine for output while still in the catheter bag. There are several different kinds of drainage bags. Get to know your facilities bags to ensure their proper use. If you do not close the bag correctly after emptying, urine will drain all over the floor.

Catheters are a must with some patients even though they are a huge sources of infection and discomfort, so we as nurses need to do our part in helping the patient be comfortable and free of infection while they have a catheter. Once it has been decided that a patent is going to have a catheter removed it is time for bladder training. Bladder training: When a catheter is in place it causes the urinary meatus to remain open. The bladder has gotten use to urine just leaving as soon as it entered, there was no need to respond in any way as to empty or not. The sphincter muscle works like a hair tie, once the elastic is held open for a long time it does not have the ability to close tightly and quickly as it had before. With bladder training we want the bladder to respond again, we want the sphincter to open and close. Most facilities have a standardized form that is used for bladder training. The form is displayed in a private manner for all nursing staff to use when caring for the patient.

The forms are different in each facility but serve the same purpose. The catheter is clapped for a stated amount of time, the time is gradually increased as the patient is able to tolerate. all times of clamp and unclamp are documented on the form. Many times a patient becomes anxious and says they canít hold it, ensure them the catheter is still in place and all is fine. Once the catheter has been removed bladder, training continues until we see everything is back on track. It is very important to monitor output after the catheter is removed to avoid retention and incontinence.

As you can see the urinary system is very complex and the nurseís role is very important. One of the most important things you need to remember is privacy in all aspects of nursing.

When it comes to the patient and the urinary system put yourself in their place, provide privacy and dignity with all of your care. When you place a patient on a bedpan or get them up to use a commode; pull the curtain, shut the door, and encourage them to do as much for themselves as possible.

Stay near by so you can be readily available to assist them as needed. No one wants to have a catheter. No one wants to be incontinent. Smile and be professional. Keep yourself informed, there are always new things happening in the medical field.

You are special and you deserve the best, and that means to broaden your horizons, grow, learn...

Thank You and God Bless.