Question

1. List the components of the urinary tract from the renal pelvis outward.
2. Why would water facilitate the passage of kidney stones?
3. Why would water aid in the prevention of developing future kidney stones?
4. List the three stages in the formation of urine and describe each stage with regard to the structures involved and the direction substance transport.
5. The glomerular filtrate concentration of calcium (Ca⁺²) is about 4 mEq/L. The concentration of calcium in the urine is about 5 mEq/L. How would you explain this difference?

Case Study

Peter, a forty-three year old office worker, was struck with a very sudden and intense pain in his side and lower back. He was breathing deeply, and the pain began to recede. Eight minutes later, the pain was not as severe but Peter was still uncomfortable and called his physician. One of Peters’s colleagues drove Peter to the doctor’s office. While on the way to his appointment, Peter experienced another bout of severe pain and began to feel nauseous. The pain seemed to be spreading into his lower abdomen and groin.

After asking Peter a few questions about his symptoms, the doctor requested an abdominal x-ray, several blood tests, and urinalysis. As Peter supplied the urine sample he was disturbed to notice that the urine had a pinkish cast. The physician returned and informed Peter that he had a kidney stone which, based on its size, should pass on its own within a day or so. The doctor told Peter that he should rest at home until the stone passed, drink at least 2-3 quarts of water each day, and strain his urine in order to retrieve the stone for analysis. The doctor also gave Peter a prescription for pain medication.

Answer 1

Ans) The components of the urinary tract from the renal pelvis outward are renal pelvis, calyces, medulla, cortex, kidney, ureter, renal vein, renal artery.

- The water would help to flush the stone through the urinary tract.

But water also happens to be the best way to prevent kidney stones. Our bodies naturally create waste chemicals as byproducts of digestion, breathing and other metabolic processes. Our kidneys collect that waste, mix it with water and flush it out as urine. The less we drink, the longer those chemicals hang around.

- Drinking enough liquid each day is the most important lifestyle habit to help prevent kidney stones. Drinking enough liquid keeps urine diluted and helps flush away minerals that might form stones.

- Filtration, Reabsorption, Secretion: The Three Steps of Urine Formation. The kidneys filter unwanted substances from the blood and produce urine to excrete them. There are three main steps of urine formation: glomerular filtration, reabsorption, and secretion.

- Glomerular filtration - Movement of substances from the glomerular capillaries into the renal tubule.

 Tubular reabsorption - Movement of substances from the renal tubule into the peritubular capillaries.

 Tubular secretion - Movement of substances from the peritubular capillaries into the renal tubule.