Page 195 - 84 human physiolofy part-1

The Urinary System

excretion (diuresis). Diuretics also decrease the extracellular fluid (ECF) volume, and are primarily
used to produce a negative extracellular fluid balance. Caffeine, cranberry juice and alcohol are all
weak diuretics. In medicine, diuretics are used to treat heart failure, liver cirrhosis, hypertension and
certain kidney diseases. Diuretics alleviate the symptoms of these diseases by causing sodium and
water loss through the urine. As urine is produced by the kidney, sodium and water – which cause
edema related to the disease – move into the blood to replace the volume lost as urine, thereby reducing
the pathological edema. Some diuretics, such as acetazolamide, help to make the urine more alkaline
and are helpful in increasing excretion of substances such as aspirin in cases of overdose or poisoning.
The antihypertensive actions of some diuretics (thiazides and loop diuretics in particular) are
independent of their diuretic effect. That is, the reduction in blood pressure is not due to decreased
blood volume resulting from increased urine production, but occurs through other mechanisms and at
lower doses than that required to produce diuresis. Indapamide was specifically designed with this is
mind, and has a larger therapeutic window for hypertension (without pronounced diuresis) than most
other diuretics. Chemically, diuretics are a diverse group of compounds that either stimulate or inhibit
various hormones that naturally occur in the body to regulate urine production by the kidneys. Alcohol
produces diuresis through modulation of the vasopressin system.

Diseases of the Kidney

Diabetic nephropathy (nephropatia diabetica), also known as Kimmelstiel-Wilson syndrome and
intercapillary glomerulonephritis, is a progressive kidney disease caused by angiopathy of capillaries in
the kidney glomeruli. It is characterized by nodular glomerulosclerosis. It is due to longstanding
diabetes mellitus, and is a prime cause for dialysis in many Western countries.

In medicine, hematuria (or "haematuria") is the presence of blood in the urine. It is a sign of a
large number of diseases of the kidneys and the urinary tract, ranging from trivial to lethal.

Kidney stones, also known as nephrolithiases, urolithiases or renal calculi, are solid accretions
(crystals) of dissolved minerals in urine found inside the kidneys or ureters. They vary in size from as
small as a grain of sand to as large as a golf ball. Kidney stones typically leave the body in the urine
stream; if they grow relatively large before passing (on the order of millimeters), obstruction of a ureter
and distention with urine can cause severe pain most commonly felt in the flank, lower abdomen and
groin. Kidney stones are unrelated to gallstones.

Case Study I was 34 weeks pregnant when I noticed blood in my urine. I immediately went to my
OBGYN where I was told that I had a bladder infection and given an antibiotic. The next morning I
experienced the most intense pain. I was rushed to the ER where I was told that I had kidney stones.
The doctors explained that there was nothing they could do as long as I was pregnant. The next 3 weeks
of my life were filled with intense pain and multiple painkillers. After I delivered my baby, CAT scans
were done and I was informed that I had 6 kidney stones. It took three more weeks for me to pass all of
the stones the largest measuring 5 mm. The stones were tested and I was informed that my body had
been building up calcium due to my pregnancy and this was the cause of the kidney stones. I continued
to have kidney pain for 6 months after passing the stones. I now live my life on a low calcium diet and
the hope that my body will not develop more kidney stones.

Pyelonephritis When an infection of the renal pelvis and calices, called pyelitis, spreads to
involve the rest of the kidney as well, the result is pyelonephritis. It usually results from the spread of
fecal bacterium Escherichia coli from the anal region superiorly through the urinary tract. In severe

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