비뇨기계 - Urinary System -

2008. 5. 29

김 춘 배

비뇨기계 (Urinary System)

방광암 (Bladder cancer)

신장암 ( Kidney cancer)

Urinary Tract

The structure of the urinary tract includes: kidneys, two ureters (tubes leading from the kidneys to the bladder), bladder, and urethra (a tube leading 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 and salts to flow through them.

The kidneys make up a filter system for the blood, reabsorbing almost 99%% of the fluid into the blood, and sending only two to four pints of waste (urine) into the bladder for storage until it can be disposed of.

The kidneys allow the blood to keep glucose, salts and minerals after cleansing it of poisonous materials which will be passed out in the urinary tract.

Urine is produced in the kidneys and trickles down twenty-four hours a day through two ten to twelve inch long tubes called ureters, which connect the kidneys to the bladder.

Kidney Function (I) The kidneys are a pair of organs located on either side of the abdomen

that remove waste products from the blood and produce urine. They perform the following major functions:

(1) Remove wastes and toxins from the blood. (2) Regulate the level of electrolytes in the blood such as hydrogen, sod

ium, potassium and phosphate. The electrolytes are pumped out and returned to the blood.

(3) Balance the body’s fluid content. (4) Make hormones that regulate blood pressure and produce red blood

cells. (5) Activate vitamin D to maintain the health of bones. The prime function of the kidneys is waste removal. As blood flows into

the kidneys, these organs filter waste products, chemicals and excess water. All of this collects as urine in the middle of the kidney in an area called the renal pelvis.

The urine in the renal pelvis drains from each kidney through a long tube (called the ureter) and into the bladder, where it is stored until releas

ed through urination.

Kidney Function (II)

Creatinine and blood urea nitrogen (BUN) are among the waste products filtered by the kidneys. They are the result of the normal breakdown o

f active muscle and dietary protein. Water-soluble toxins are also filtered from the blood. Tiny units called n

ephrons provide the filtering in the kidneys.

Kidney Function (III)

The kidneys use several mechanisms to keep certain chemicals in the blood in balance. These include electrolytes, acids and bases. The kidneys perform this chemical balancing act by excreting excess chemicals into the urine, and conserving other chemicals when they are lacking in the blood.

The kidneys are also responsible for releasing three key hormones:

(1) Renin. Released when blood pressure is low, it causes blood vessels to constrict and brings the pressure back to normal.

(2) Erythropoietin. Directs bone marrow to make red blood cells. These cells carry oxygen throughout the body.

(3) Calcitriol. The active form of vitamin D, it helps maintain calci

um for the bones.

Kidney Function (IV)

For people with diabetes, control of glucose (blood sugar) and blood pressure is crucial in maintaining kidney function. Excess glucose (hyperglycemia) and high blood pressure can lead to diabetic nephropathy.

In addition, recent studies link obesity to impaired kidney function. High levels of LDL “bad” cholesterol can impair kidney function, but recent research into type 1 diabetes suggests that HDL “good” cholesterol can protect the kidneys.

Methods of assessing kidney function

Major tests of kidney function include: (1) Serum creatinine test. A blood test that measures the level of the waste product creatini

ne in the blood. Creatinine comes from two sources: meat products in the diet and from wear and tear on the muscles. Almost all of it eventually ends up in a person’s urine.

(2) Blood urea nitrogen (BUN) test. A blood test that determines the level of urea nitrogen in the blood. Urea nitrogen is produced from a breakdown of food Protein.

(3) Creatinine urine test. Measures the amount of creatinine in the urine. (4) Creatinine clearance test. A 24-hour urine test that measures the amount of blood being

filtered each minute by the kidneys. (5) Microalbuminuria test. Patients are advised to request a special urine test for microalbu

minuria (presence of small amounts of protein in the urine) rather than a urinalysis for proteinuria (larger amounts of protein in urine). A microalbuminuria test can reveal kidney disease earlier, leading to treatments that can maximize kidney function.

(5) Glomerular filtration rate (GFR). A measurement of the amount of glomerular filtrate (a substance similar to plasma but without proteins) formed in the kidneys each minute. GFR is estimated indirectly through other tests such as creatinine clearance, serum creatinine, inulin clearance (test involving time urine collections after intravenous administration of a sugar) or equations such as the Modification of Diet in Renal Disease (MDRD) equation.

Kidney diseases and disorders (I)

Disease, birth defects and injuries can all affect the kidneys’ ability to function. Diabetes frequently leads to a slow deterioration of the kidneys known as diabetic nephropathy. The end result of nephropathy is kidney failure, which is an inability to filter waste products or to regulate the body’s balance of salt and water.

More than 40 percent of all new cases of kidney failure are attributed to diabetes, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Nephropathy is more common in patients with type 1 diabetes but also occurs in those with type 2 diabetes (especially if diagnosed at a young age) and other forms of diabetes, such as maturity-onset diabetes of the young (MODY). Recent research shows that nephropathy can even affect people with prediabetes.

Kidney diseases and disorders (II)

Symptoms often do not appear until the late stages of the disease, when kidney failure is a present danger.

There are three kinds of kidney failure: (1) Acute renal failure. The kidneys cease functioning properly

because of a sudden illness, trauma, a medication or a medical condition. In some cases, this may go away on its own, with patients recovering within a few days. How long the illness lasts depends on the cause of the kidney problem.

(2) Chronic renal failure. Kidney function gradually declines, usually over a period of years. It is most often the result of illnesses such as diabetes, uncontrolled high blood pressure (hypertension) or chronic kidney inflammation.(3) End-stage renal disease (ESRD). Kidney function declines until the point where the person will die without dialysis or a kidney transplant. This is usually the result of longstanding chronic renal failure, but can also follow acute renal failure.

Kidney diseases and disorders (III)

Symptoms of the various forms of kidney failure include:

Acute kidney failure - Fluid retention (edema), Confusion, Seizures, Coma Chronic kidney failure - High blood pressure, Anemia, Nausea or vomiting,

Malaise or fatigue, Decreased urine output, Unexplained weight loss, Decreased alertness, Sleep disorders, Persistent itching, Muscle twitches or cramps, Headaches that appear unrelated to another cause, Yellowish-brown cast to the skin

End-stage renal disease - Anemia, High blood pressure, Congestive heart

failure, Bone disease, Digestive tract problems, Loss of mental function (dementia)

Kidney diseases and disorders (IV)

If damage becomes severe enough, patients may require either a kidney transplant or undergo dialysis treatment. Dialysis occurs in one of two forms:

(1) Hemodialysis. A machine replaces the work of the kidneys by filtering blood. The cleaned blood is then returned to the body.

(2) Peritoneal dialysis. The lining of the patient’s abdomen (peritoneal membrane) is used as the filter. A catheter is surgically inserted through the wall of the abdomen, and a dialysis solution is introduced into the abdominal cavity. This solution removes waste products and excess fluids from the

bloodstream.

Urinary tract infection (UTI)

A urinary tract infection (UTI) is among the more common urinary and bladder conditions.

Interstitial cystitis can involve painful urination and the frequent need to urinate.

Other conditions include cystocele (dropped bladder) and urethral syndrome (inflammation with no sign of UTI).

Kegel exercises may help people with urinary incontinence or related symptoms.

General Information on Kidney

Diabetes is a common cause of kidney failure.

The kidneys leak proteins into the urine while retaining waste that should be expelled.

End-stage renal failure occurs when the buildup of wastes begin to sicken the body.

The only treatments for kidney failure are dialysis or kidney transplant.

Diabetic kidney disease (nephropathy) may go undetected until serious damage is done.