Textbook For Nursing Assistants Chapter 32 - The Urinary System Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Structure of the Urinary System Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Structure of the Urinary System The urinary system consists of The kidneys The ureters The urinary bladder The urethra Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Structure of the Urinary System: The Kidneys We have two kidneys, which are like kidney beans in shape and color (only much larger!) The kidneys are located toward the back of the upper abdominal cavity, one on either side of the spinal column Because the job of the kidneys is to filter the blood to remove waste products, the kidneys are supplied by two large arteries, called the left and right renal arteries The renal arteries are branches of the aorta, the largest artery in the body The blood flow through the renal arteries is so efficient that the kidneys are able to filter all of the body’s blood every half-hour Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Structure of the Urinary System: The Kidneys Inside each kidney are approximately 1 million tiny nephrons, the basic functional units of the kidney The nephrons are responsible for actually filtering the blood that passes through the kidney Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Structure of the Urinary System: The Kidneys Each nephron consists of a glomerulus and a series of tubules Glomerulus: a capillary bed, enclosed within a structure called the Bowman’s capsule The blood enters the glomerulus through a vessel called the afferent arteriole The walls of the capillaries in the glomerulus are semi-permeable, which means that they have tiny openings in them Because the blood is under a lot of pressure, a lot of the liquid in the blood squeezes through the walls, taking the wastes and nutrients that are dissolved in it with it. This liquid, known as the filtrate, forms the basis of the urine Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Structure of the Urinary System: The Kidneys Next, two things happen: Filtered blood leaves the glomerulus through the efferent arteriole and is returned to circulation through the renal veins Filtrate enters the Bowman’s capsule, and from there, flows into the tubules that make up the rest of the nephron. As the filtrate passes slowly through the tubules, small capillaries reabsorb useful substances such as water, nutrients, and minerals from the filtrate. By the time the filtrate reaches the end of the tubules, only excess fluid and waste substances remain. This is urine. Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

From the renal pelvis, the urine flows into the ureters Structure of the Urinary System: The Kidneys The kidneys produce 160 to 180 liters of filtrate each day, but only about 1 to 1.5 liters is excreted from the body in the form of urine Urine from each nephron is emptied into a collecting area, called the renal pelvis From the renal pelvis, the urine flows into the ureters Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Structure of the Urinary System: The Ureters Two ureters, slender, muscular tubes approximately 10 to 13 inches (25 to 32 cm) long, carry urine from the kidneys to the bladder The ureters are wider at the top where they connect to the renal pelvis, but they quickly become very narrow Where the two ureters enter the bladder, a small triangular fold of tissue called the trigone keeps urine from flowing back into the ureters after it has emptied into the bladder Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Structure of the Urinary System: The Ureters The ureters are lined with a mucous membrane, which helps to protect against infection Smooth muscle in the walls of the ureters contracts rhythmically, moving urine away from the kidney and toward the urinary bladder The peristaltic movements that help move urine through the ureters are similar to the peristaltic movements that help move food through the digestive tract Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Structure of the Urinary System: The Bladder The bladder is a hollow sac that is a holding place (reservoir) for urine Urine is constantly produced by the kidneys and transported through the ureters to the bladder, where it is stored until urination occurs The bladder is very small when empty but can become quite large as it fills with urine Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Structure of the Urinary System: The Bladder Like the ureters, the inside of the bladder is lined with a mucous membrane The walls of the bladder contain three layers of smooth muscle When the walls of the bladder contract, urination occurs Where the bladder and the urethra join (the bladder outlet), the internal sphincter (a ring of involuntary muscle) keeps the bladder closed while it fills Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Structure of the Urinary System: The Urethra The urethra is a tube that carries urine from the bladder to the outside of the body The urethra begins at the bladder outlet, just below the internal sphincter, and ends at the external urinary opening (called the urinary meatus or urethral orifice) Below the internal sphincter, the external urethral sphincter, a ring of voluntary muscle, relaxes to allow urine to pass during urination Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Male and female urethras are very different in size and function Structure of the Urinary System: The Urethra Male and female urethras are very different in size and function Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Structure of the Urinary System: The Urethra In Women In Men The urethra measures about 1 ½ to 2 ½ inches and is only used as a passageway for urine to leave the body The urethra is straight The urethra measures about 6 to 8 inches and serves as a passageway for both urine and semen The urethra is curved Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Function of the Urinary System Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Removal of Liquid Wastes A moderately full bladder usually contains about 1 pint (470 ml) of urine When about 200 to 300 ml of urine collects in the bladder, the internal sphincter opens and allows urine to flood the upper segment of the urethra At this point, the urge to urinate occurs The person voluntarily relaxes the external urethral sphincter and the muscles of the bladder contract, allowing urine to pass out of the body through the urethra Although it is possible to delay urination for some time, the bladder continues to fill with urine and eventually, the bladder will empty itself automatically Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Maintenance of Homeostasis The urinary system helps to keep fluid levels within the body constant As the filtrate passes through the tubules in the nephrons, water is reabsorbed as necessary to maintain the body’s fluid balance Too much fluid in the blood can lead to fluid overload, causing swelling in parts of the body Too little fluid can lead to dehydration Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Maintenance of Homeostasis The urinary system regulates the levels of essential minerals such as potassium, calcium, and sodium by either saving them or releasing them through urine Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Maintenance of Homeostasis The urinary system regulates the acidity of the blood Human blood is slightly above a 7 on the pH scale, which ranges from 1 to 14 Anything above 7 is said to be basic, or alkaline Anything below 7 is acidic Our blood cannot be either too acidic or too basic When there is even a slight change in the blood’s pH, damage to the cells can occur Acid is a normal byproduct of cellular metabolism So, to maintain the blood at a constant pH level, the kidneys excrete the excess acids produced by cellular metabolism Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

The Effects of Aging on the Urinary System Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Less efficient filtration The Effects of Aging on the Urinary System Less efficient filtration After a person reaches 40 years of age or so, the number of functioning nephrons in the kidneys starts to decrease, decreasing the kidneys’ ability to filter waste products from the bloodstream Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Decreased muscle tone The Effects of Aging on the Urinary System Loss of muscle tone as a result of aging can reduce bladder capacity and may contribute to stress incontinence This type of urinary incontinence, which is most common in older women who have had children or are obese, can often be corrected with exercises or surgery Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Enlargement of the prostate gland (in men) The Effects of Aging on the Urinary System Enlargement of the prostate gland (in men) Common in older men Enlargement may be benign (a normal effect of aging) or it may be due to cancer of the gland Total emptying of the bladder of urine becomes difficult, and the man may experience episodes of overflow incontinence or dribbling Treated with surgery, medications, or both Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Increased risk for urinary tract infections The Effects of Aging on the Urinary System Increased risk for urinary tract infections Older people are also more likely to get urinary tract infections Incomplete emptying of the bladder can contribute to the development of infections, as can a decrease in immune system functioning Signs and symptoms in older person may differ from those in younger person Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Disorders of the Urinary System Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Infection of the urethra (urethritis) Disorders of the Urinary System: Infections Infection of the urethra (urethritis) Urethritis is especially common in men, because the urethra is longer and curved Microbes responsible for sexually transmitted diseases (STDs) such as gonorrhea, herpes, and chlamydia are common causes of urethritis in men Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Infection of the bladder (cystitis) Disorders of the Urinary System: Infections Infection of the bladder (cystitis) Bladder infections are more common among women than men for two reasons: Urethral opening in women is located closer to the anus A woman’s urethra is short and straight Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Kidney infections (pyelonephritis) Disorders of the Urinary System: Infections Kidney infections (pyelonephritis) If a bladder infection is not treated promptly with appropriate drugs, the pathogens can travel up the ureters and infect the kidneys A kidney infection can cause severe illness If untreated, the infection might result in permanent damage to the nephrons Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Disorders of the Urinary System: Infections Signs and Symptoms In younger people, symptoms of urinary tract infections include urinary frequency, burning, and cramping, and fever In older people, symptoms may be different (e.g., confusion) The nursing assistant may be the first to notice a change in the appearance or odor of the urine or a change in a person’s voiding habits that would indicate that a urinary tract infection may be present Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

How are kidney stones formed? Disorders of the Urinary System: Kidney Stones How are kidney stones formed? Many waste products that the kidney filters from the blood are in the form of mineral salts, such as calcium salts and uric acid If waste products become very concentrated, they can start to group together, forming tiny crystals that continue to grow in size as more of the mineral is deposited around them These clumps of minerals are called kidney stones, or renal calculi Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Kidney stones are most common in middle-aged adults Disorders of the Urinary System: Kidney Stones Kidney stones are most common in middle-aged adults Factors that may increase an older person’s risk of developing kidney stones include Immobility Not drinking enough fluids Infections of the urinary system Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Disorders of the Urinary System: Kidney Stones Stones most often form in the collecting area (renal pelvis) of the kidney, but they can also form in the bladder Kidney stones usually cause severe pain as they move downward through the ureter, and then through the urethra The rough edges of the stone can damage the mucosal lining of the ureter or urethra, causing it to bleed, resulting in hematuria (blood in the urine) Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Medication may be necessary to help control the pain Disorders of the Urinary System: Kidney Stones A person with a kidney stone usually needs to drink plenty of fluids to help flush the stone through the urinary tract Medication may be necessary to help control the pain Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Disorders of the Urinary System: Kidney Stones You may be asked to collect all of the person’s urine after each voiding and strain it to retrieve the stone Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Disorders of the Urinary System: Kidney Stones To strain the urine, place a piece of filter paper or a 4 x 4 gauze pad in a graduate, and then pour the urine into the graduate The urine will pass through the filter paper or gauze pad, leaving any stones behind It is important to retrieve the kidney stones because then they can be sent to the laboratory for chemical analysis Once the doctor knows what waste salt is causing the stones to form, he may be able to prevent future stones from developing Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Sometimes, surgery is necessary for stone removal. Disorders of the Urinary System: Kidney Stones Often, the stones are removed using a procedure called lithotripsy. In lithotripsy, high-frequency sound waves are directed at the stone, causing it to break into smaller pieces that can then be passed through the urinary tract. Sometimes, surgery is necessary for stone removal. Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Disorders of the Urinary System: Kidney Failure Kidney (renal) failure: the inability of the kidneys to filter blood effectively The person becomes very ill and can easily die if treatment is delayed. Causes of kidney failure Acute kidney failure Medical or surgical emergency that causes a decrease in the amount of blood flow through the kidneys Poisoning, a severe infection, or a severe allergic reaction Chronic kidney failure Hypertension Diabetes Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Disorders of the Urinary System: Kidney Failure Signs of renal failure Dehydration from excessive loss of fluid (usually early in acute renal failure because the kidneys cannot reabsorb filtrate back into the bloodstream) Swelling from the build-up of fluid in the tissues of the body (later in chronic renal failure when the kidneys are unable to eliminate excess fluid) Hypertension from fluid overload in the circulation Oliguria (scant amounts of urine, less than 400 ml in 24 hours), followed by anuria (the absence of urine) Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Disorders of the Urinary System: Kidney Failure Dialysis Dialysis does the job of the kidneys by removing waste products and fluids from the body A person with acute renal failure may only need dialysis treatment for a short period of time, until kidney function returns A person with chronic renal failure must remain on dialysis for the rest of her life, or until a donor kidney becomes available for transplant Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Disorders of the Urinary System: Kidney Failure Hemodialysis The person’s blood is drawn intravenously, passed through a machine with filters and solutions that clean the blood of waste, and then returned to the person’s body through another vessel Peritoneal dialysis Solutions that absorb waste products are instilled (placed) into a person’s abdominal cavity through a tube that has been surgically inserted for this purpose The solution remains in the abdominal cavity for a specified period of time so that waste products can be absorbed into the solution through the membrane lining the abdominal cavity The used solution is then drained into a collecting bag and is discarded according to facility policy Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Disorders of the Urinary System: Kidney Failure When caring for a person with renal failure: Carefully measure the amounts of urine produced and document the amounts accurately You may be frequently asked to obtain urine samples so that the urine can be tested for the presence of excessive waste products Vital signs may need to be monitored frequently and any changes reported to the nurse immediately People in renal failure may be on bed rest and need care measures to help prevent the complications of immobility Frequent skin care is necessary to help prevent the skin irritation and itching that accompanies renal failure Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Disorders of the Urinary System: Tumors Tumors, which may or may not be malignant (cancerous), can affect all of the organs of the urinary system Tumors can obstruct the flow of urine through the urinary system, resulting in kidney damage Tumors of the kidney Tumors invade the healthy tissue, damaging the nephrons Surgical removal of the affected kidney is usually necessary, but as long as the remaining kidney is functioning properly, it should be able to handle removal of waste and fluid Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Disorders of the Urinary System: Tumors Tumors of the bladder Common among people who have smoked cigarettes Risk increases with age, with older men twice as likely to develop bladder cancer as older women Usually malignant and may spread to other organs May be treated with medication, radiation, or surgery, depending on the type of tumor and whether or not it has spread to other parts of the body In some cases, it is necessary to remove the bladder, disrupting normal flow of urine out of the body Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

A surgeon can create a urinary diversion through a: Disorders of the Urinary System: Tumors Because the urine needs a new pathway to leave the body, a urinary diversion is created A surgeon can create a urinary diversion through a: Ureterostomy OR Urostomy Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Disorders of the Urinary System: Tumors Ureterostomy In a ureterostomy, the ureters are brought through the abdominal wall by way of small incisions, and sutured in place The ureters then drain freely into an ostomy appliance designed to collect urine Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Urostomy Disorders of the Urinary System: Tumors In a urostomy, the ureters are attached to a small portion of the small intestine (usually the ileum) When the ileum is used, the person is said to have an ileal conduit Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Disorders of the Urinary System: Tumors Urinary diversion may be necessary because of: Bladder cancer Injuries (for example, to the bladder or spinal cord) Birth defects (such as spina bifida) Care of a person with an ostomy Good skin care around the ostomy site is essential: if urine is allowed to leak around the appliance, skin irritation and breakdown are very likely The urostomy bags need to be emptied regularly and the urine may need to be measured and recorded As always, the urine needs to be observed for any changes that might indicate infection or other urinary disorders Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Diagnosis of Urinary Disorders Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

Diagnosis of Urinary Disorders Urinalysis: the urine is examined under a microscope and by chemical means Imaging studies: allow a doctor to see tumors and other abnormalities of the urinary system Computed tomography (CT) scans, magnetic resonance imaging (MRI) scans, and radiographs (x-rays) Ultrasound: may be used to detect tumors of the urinary system Cytoscopy and ureteroscopy: a small, lighted scope is inserted through the urethra and used to view the inside of the bladder (cytoscopy) or ureters (ureteroscopy) Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.

End of Presentation Copyright © 2005.  Lippincott Williams & Wilkins. Instructor's Manual to Accompany Lippincott's Textbook for Nursing Assistants.