kidney function

Under normal circumstances, humans have two kidneys. Each kidney has a ureter that drains urine from the renal pelvis (kidney which is a central part of the collection of urine) into the bladder. Of the bladder, the urine flows through the urethra, leaving the body through the penis (male) and vulva (women).

kidney function is to:

Filtering of metabolic waste
Filter out excess sodium and water from the blood
Helps remove waste products and excess sodium and water from the body
Helps regulate blood pressure
Helps regulate blood cell formation.

Each kidney consists of about 1 million filtering units (nephrons). A nephron is a structure that resembles a bowl with a perforated wall (Bowman's capsule), which contains a tuft of blood vessels (glomerulus). Bowman's capsule and the renal glomerulus korpuskulum form.

Blood entering the glomerulus has a high pressure. Most of the blood in the form of filtered fluid through small holes in the walls of blood vessels in the glomerulus and the inner lining of Bowman's capsule; so the only remaining blood cells and large molecules (eg proteins).

The fluid was filtered (filtrate) into the cavity of Bowman (area located between the inner layer and outer layer of Bowman's capsule) and flows into the proximal convoluted tubule (tube / channel upstream from the Bowman's capsule); sodium, water, glucose, and other materials which come filtered reabsorbed and returned to the blood.

The kidneys also use energy to selectively move large molecules (including drugs, eg penicillin) into the tubule. The molecule is discharged into the urine although its size is large enough to be able to pass through the holes on the filter glomerulus.

The next part of the nephron was Ansa Henle. When liquid is passed Ansa Henle, sodium and some other electrolyte is pumped out so that the remaining liquid becomes more concentrated. This concentrated liquid that will flow into the distal convoluted tubule. In the distal tubule, the more the amount of sodium is pumped out.

Fluid from several nephrons flows into a collecting ducts (collecting ducts). In the collecting ducts, the fluid continues to pass through the kidney as a concentrated liquid, or if it is still runny, then the water will be absorbed from the urine and returned to the blood, so that the urine becomes more concentrated. The body controls the concentration of the urine based on its needs for water through the hormones that affect kidney function works.

Urine that form in the kidneys flows down through the ureter toward the bladder; flow is not a passive flow. The ureter is the tube / muscular tube that drives a number of urine in a wavy motion (contraction). Each ureter will go into the bladder through a sphincter. Sphincter is a muscular structure (muscular) which can be opened (so that urine can pass) and close.

Urine that regularly flow from the ureter will be collected in the bladder. This could inflate the bladder, which is gradually enlarged in size to accommodate the amount of urine increased. If the bladder is full, it will send nerve signals to the brain, which convey messages to urinate.

During urination, another sphincter located between the bladder and urethra will open so that urine flows out. Simultaneously, the bladder wall to contract, causing pressure to push urine into the urethra. This pressure can be magnified by tightening the abdominal muscles. Sfinger at the entrance of the bladder remains shut to prevent backflow of urine into the ureters.


SYMPTOMS KIDNEY AND URINARY TRACT DISORDERS

Symptoms are caused by abnormalities of the kidneys and urinary tract vary widely, depending on the kidney or urinary tract is affected. Fever and malaise (feeling unwell) is a common symptom, but a bladder infection (cystitis) usually does not cause fever. A bacterial infection of the kidneys (pyelonephritis) usually causes a high fever. Kidney cancer sometimes causes fever.

Most people do urinate as much as 4-6 times / day, mainly in the afternoon. Frequency (frequent urination) without an accompanying increase in the total amount of urine in a day, is a symptom of a bladder infection or bladder irritation (eg due to foreign objects, stones, or tumors).

Tumors or other mass which suppresses bladder can also cause increased frequency of micturition. Bladder irritation can also cause dysuria (pain when urinating) and urgency (urge to urinate), which can be felt as tenesmus (painful straining almost felt as continuous). The amount of urine is usually small, but if the patient does not immediately urinate, the urine can come out by itself (control over urination is lost).

Nocturia is a frequent need to urinate at night. Nocturia can be occurred in the early stages of kidney disease, but could also be due before a person's sleep too much to drink, especially alcohol, coffee, or tea. Nocturia occurs because the kidneys can not concentrate urine well.

Nocturia also occur in patients with heart failure, liver failure or diabetes, although there are no abnormalities in the bladder channel.

Nocturia with the amount of urine that very little can happen when urine flows back into the bladder because of blockage; one of the reasons most often found in elderly men is prostate gland enlargement.

Enuresis (bedwetting) at the age of 2-3 years is normal. Enuresis that occurs after the age of 3, showing the existence of a problem, for example:
- Delayed maturation of muscle and nerve in the lower urinary tract
- Infection or narrowing of the urethra
- Neurogenic bladder (inadequate nerve controlling the bladder).

The symptoms are often found in the blockage of the urethra is:
- Reluctance to initiate urination,
- The need for straining,
- A weak stream or drip,
- After completion of urination, the urine still dripping.

In men, symptoms are most often caused by prostate enlargement and narrowing of the urethra (urethral stricture). Same symptoms in young males, may indicate the presence of congenital abnormalities in the form of narrowing of the urethra or opening of the urethra is very small. Small opening of the urethra which can also be found in women.

Uri incontinence (inability to hold urination) can occur in various circumstances. Cystocele (herniation / rupture of the bladder into the vagina), the urine can come out when people laugh, cough, running, or lifting heavy loads. Cystocele generally occurs due to stretching and pelvic muscle weakness (since birth) or due to changes in estrogen levels at menopause.

Blockage of flow from the bladder can cause incontinence if the pressure inside the bladder exceeds the prisoners from the blockage, although the bladder is not completely empty.

The presence of gas in the urine is a symptom of a rare, usually indicate the presence of a fistula (abnormal connection) between the urinary and intestinal tract. A fistula can be a complication of divertikulits, abscess or cancer. Fistula between the bladder and vagina can also cause the presence of gas in the urine. Sometimes the bacteria in the urine also form a gas.

Under normal circumstances, an adult throw around a cup of urine to 0.9 L / day. A variety of renal diseases causing disruption of the ability of the kidneys to concentrate urine, so the amount of urine discharged exceed 2.25 L.

The amount of urine that is very much usually the result of:
- High blood sugar levels,
- Low levels of antidiuretic hormone produced by the pituitary gland (diabetes insipidus), and
- Decrease in response to antidiuretic hormone (nephrogenic diabetes insipidus).

Kidney disease or blockage of the ureter, bladder or urethra can cause sudden loss of urine production to less than 2 cups / day. If the production of urine with less than 1 cup / day continues, there could be accumulation of metabolic wastes in the blood (azotemia). Decrease the amount of urine may indicate the acute renal failure or worsening of a chronic kidney disorder.

Urine (urine) that dilute nearly colorless, while the urine is dark yellow solid. Dyes in food can cause red-colored urine, whereas the drugs can cause urine brown, black, blue, green or red. In addition to its food or medicines, which are not colored yellow urine is abnormal.

Brown urine may contain breakdown products of hemoglobin (the protein that carries oxygen in red blood cells) or muscle protein. Urine containing dye porphyria due to red, while the dye due to melanoma causes the urine to black. Turbid urine which indicate the presence of pus due to a urinary tract infection or crystals of uric acid or a salt of phosphoric acid. Causes of abnormal urine color that can be known by microscopic examination of urine sediment and urine chemistry analysis.

Hematuria (blood in the urine) can cause urine red or brown, depending on the amount of blood, old blood in the urine and the acidity of urine. Haematuria without pain can result from bladder cancer or kidney cancer. Hematuria is usually intermittent, and the bleeding stopped spontaneously although the cancer was still there.

Other causes of hematuria are:
- Glomerulonephritis
- Kidney stones
- Kidney cysts
- Sickle cell disease
- Hydronephrosis.

Pain caused by kidney disease is usually felt in the back, ie in the flank area (between the ribs and hips the back). Sometimes the pain spreads to the middle of the abdomen. The cause is stretching of the renal capsule (outer kidney, which is sensitive to pain), it can happen in various circumstances that cause swelling of the kidney tissue. If the kidney is pressed, the pain often arises.

If a kidney stone through the ureter, there will be severe pain. In response to the stones, ureteric contraction resulting in severe cramping pain in lower back, often radiating to the groin. If the stone has reached the bladder, the pain will disappear.

Pain in the bladder is most often caused by bacterial infection. This pain is usually felt above the pubic bone and at the end of the urethra when urinating.
Blockage of urine flow also causes pain above the pubic bone, but if the blockage occurs slowly, usually widening of the bladder is not accompanied by pain.

Cancer and prostate enlargement does not usually cause pain, but inflammation of the prostate (orostatitis) can cause a vague pain or feeling of fullness in the area between the anus and genitals. At the time of ejaculation, sometimes out of a bloody cement. This can occur in men who suffer from clotting disorders.

DIAGNOSTIC PROCEDURES

On physical examination, normal kidney was not palpable from the outside, but a swollen kidney or kidney tumors are palpable from the outside. A swollen bladder can also be felt from the outside. Performed digital rectal examination to feel the prostate gland. Examination of the vagina can help provide information about the bladder and urethra.

Additional procedures are done to diagnose kidney and urinary tract abnormalities are:

* Analysis of urine
* Blood tests to assess kidney function
* Procedures imaging
* Examples of cells and tissues.

Analysis of urine
Routine urinalysis (urinalysis) consists of chemical analysis (for detection of proteins, sugars and ketones) and microscopic examination (to detect red blood cells and white blood cells). With this examination can be known and measured levels of various substances in the urine. Typically used a piece of thin plastic (dipstick) which contain chemicals that will react with substances in the urine and urine color change.

Proteinuria (protein in the urine) can occur continuously or intermittent, depending on the cause. Proteinuria is usually a sign of a kidney disease, but can also occur normally after strenuous sports (eg marathon). Proteinuria can also occur in orthostatic proteinuria, whereby new proteins appear in urine after standing for a long time sufferer, and will not be found in the urine after the sufferer lay.

Glucosuria (sugar in the urine) is usually caused by diabetes. If sugar remains found in the urine after normal blood sugar levels, then the cause is an abnormality in the kidney.

Ketonuria (ketones in the urine) can be caused by starvation, uncontrolled diabetes and alcohol poisoning. Ketone is the result of the breakdown of fat by the body.

Hematuria (blood in the urine) can be known through microscopic examination or with the naked eye (if the blood very much, the urine becomes red or brown).

Nitrituria (nitrate in the urine) usually indicates the presence of infection, because the nitrate levels increase when there is bacteria.

Leukocyte esterase (an enzyme found in certain white blood cells) in the urine is a sign of inflammation, most commonly caused by bacterial infection.
This examination may be a false negative if the urine is very concentrated or containing sugar, bile salts, drugs (eg rifampcin, vitamin C).

The acidity of urine may increase due to certain foods.

Osmolarity (concentrated urine) is important in diagnosing abnormal kidney function. Can be analyzed on a random urine sample or examination to assess the ability of the kidneys in urine concentrating. In one test, a person is not allowed to drink water or other liquids for 12-14 hours, while in other tests given injections of the hormone vasopressin. Then the concentration of urine was measured.

Under normal circumstances, the two tests should show a highly concentrated urine, but in certain kidney diseases, the urine becomes very dilute.

Under normal circumstances, urine contains a small number of cells and other fractions separated from the inside of the urinary tract. In patients with urinary tract abnormalities, and cell fragments are present in excessive amounts, so that if the urine is centrifuged (played in a special tool) will be formed sediment (sediment). These sediments can be examined with a microscope to determine the illness.

Urine culture is a process for growing the bacteria in the urine, which is done to diagnose a urinary tract infection.

Urine samples are not contaminated can be obtained through:
- Clean-catch method
- Catheter inserted through the urethra into the bladder
- The needle is inserted through the abdominal wall into the bladder (suprapubic needle aspiration).

Kidney Function Tests
Kidney function can be assessed through analysis of blood and urine. The rate of kidney filtration can be estimated by measuring serum creatinine. Blood urea nitrogen levels also can indicate kidney function.

Creatinine clearance is a more accurate test, which uses a formula relating the levels of serum creatinine with age, weight and gender.

Imaging Procedures
Plain photo abdomen can show the size and location of the kidney, but both of these will usually look better on ultrasound examination.

Intravenous urography is an x-ray technique that is used to display the kidney and lower urinary tract. Radioopak a substance is injected through a vein. Substances will be contained in the kidneys usually in less than 5 minutes. Then do the shooting, the results will show the picture as well as travel agents radioopak kidney into the bladder.

If the kidneys are not functioning properly, then intravenous urography will not give good results, because the kidneys can not concentrate radioopak substances in the kidneys.

As a side effect of the injection of substances radioopak, acute renal failure occurs in 1 in 200 cases. The cause is unknown, but the risk is higher in:
- Elderly or have a history of renal impairment
- Diabetes mellitus
- Dehydration
- Multiple myeloma.

To these people, before the substance is injected radioopak, given intravenous fluids and low dose. Or as an option, sometimes used a CT scan.

Cystogram is an x-ray image of the bladder, which is obtained through an intravenous urography. Retrograde cystogram is obtained by inserting radioopak substances through the urethra, in order to get a clearer picture of the bladder and urethra. X-rays taken before, during and after micturition.

In retrograde urography, radioopak substance through a catheter inserted into the ureter. With this technique will obtain a clear picture of the bladder, ureters, and kidneys bottom, if it fails intravenous urography. Retrograde urography can also be used to find the blockage of the ureter or to assess someone who is allergic to a substance radioopak intravenously. The disadvantage of this technique is the risk of infection and anesthesia needs to be done.

Ultrasound uses sound waves to produce a picture of the anatomical structure of the kidney. The technique is simple, painless and safe.

Ultrasound can be used to:
- Studying the kidneys, ureters and bladder; with a good picture even though the kidneys are not functioning properly.
- Measuring the rate of formation of urine in fetuses older than 20 weeks by measuring changes in bladder volume. Thus can be known fetal renal function.
- In the newborn, ultrasound is the best way to determine the existence of mass in the abdomen, urinary tract infections and congenital abnormalities of the urinary system.
- Estimating the size of the kidneys and to diagnose a number of renal disorders, including renal bleeding.
- Determine the best location in order to take tissue samples for biopsy.

Ultrasound is the best diagnostic method for patients with advanced renal failure, the kidneys can not take or tolerate radioopak substances. Bladder filled with urine can be seen clearly on ultrasound. Ultrasound can also be used to detect bladder tumors, but the results are better used CT scans.

CT scan is an examination that is more expensive than ultrasound and intravenous urography, but has several advantages:
- CT scans can distinguish solid structure with fluid, making it very useful in assessing the type and extent of renal tumors or other mass that causes changes in the urinary tract. To give a clearer picture, can be injected through a vein radioopak substances.
- CT scan can help determine the tumor has spread outside the kidney.
- The mixture of water and substances radioopak inserted into the bladder during a CT scan can clearly depict bladder tumors.

At angiography radioopak injected substances into the artery. Angiography is the examination of the most invasive and only performed in certain circumstances, for example, to assess blood flow to the kidneys. Complications of angiography is an injury to the artery and surrounding organs, reactions to substances radioopak and bleeding.

Venografi is an x-ray that uses veins radioopak substances. Complications are rare and usually confined to the seepage of blood and the substances radioopak around the injection site. Can occur radioopak allergic reactions to substances.

MRI scans can provide information about renal masses that can not be displayed by other techniques. Form of a tumor can be described in three dimensions. Solid masses can be distinguished from the mass hollow (cysts), the fluid inside the cyst can be differentiated between bleeding with infection. MRI also provides a perfect illustration of the blood vessels and structures around the kidneys. But calcium deposits and kidney stones will be more clearly seen on CT scans.

Sample Cell and Tissue
On renal biopsy, renal tissue samples taken and examined under a microscope. A biopsy performed to confirm the diagnosis and to assess treatment outcomes.

Biopsy needle (inserting a needle through the skin) is often a part of the assessment in renal failure and biopsy of the transplanted kidney is often performed to look for signs of rejection.

Urine cytology is a microscopic examination of cells in the urine. This check is done to diagnose urinary tract cancer. Urine cytology was also performed as a screening (screening) of cancer in high risk people (eg smokers, petrochemical workers, and patients with bleeding without pain).

For patients who had undergone surgical removal of the bladder or kidney tumor, cytology was performed for evaluation of follow-up.