G12 C4 Urinary System Short Question Answers

Chapter 4 Urinary system Short Question Answers NBF

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1. Name the organs of the urinary system and write their major functions.

The urinary system consists of the kidneys (to filter blood and produce urine), ureters (to transport urine), a urinary bladder (to store urine), and the urethra (to expel urine from the body).

2. Describe glomerular filtration.

Glomerular filtration is the first step in urine formation. Due to high blood pressure, water, ions, and small waste molecules are forced out of the glomerular capillaries into Bowman's capsule, forming glomerular filtrate. Large proteins and blood cells are not filtered.

3. Describe the countercurrent multiplier mechanism.

This mechanism, involving the Loop of Henle and vasa recta, creates a concentrated osmotic gradient in the kidney medulla. The ascending limb pumps out solutes, and the descending limb loses water, concentrating the fluid and enabling the production of hypertonic urine.

4. Name the parts of a nephron and trace the blood supply to the nephron.

A nephron consists of the renal corpuscle (glomerulus and Bowman's capsule) and the renal tubule (proximal convoluted tubule, Loop of Henle, distal convoluted tubule). Blood enters through the afferent arteriole and leaves through the efferent arteriole.

5. Name general processes which are involved with urine formation?

The three main processes involved in urine formation are: 1. Glomerular filtration, where blood is filtered. 2. Tubular reabsorption, where essential substances are reabsorbed. 3. Tubular secretion, where additional wastes are secreted into the tubule.

6. Describe urinary tract infection.

A urinary tract infection (UTI) is an infection of any part of the urinary system. Common types include urethritis, cystitis, and pyelonephritis, which can be caused by bacteria and are more common in women due to anatomical differences.

7. Name three urinary tract infections and bacteria responsible.

Three types of UTIs are: urethritis (infection of the urethra), cystitis (infection of the bladder), and pyelonephritis (infection of the kidneys). The most common bacteria responsible is Escherichia coli.

8. What are the causes of kidney failure?

Chronic renal failure is caused by bacterial infections, nephritis, high blood pressure, or diabetes mellitus. Acute renal failure can be caused by hemorrhage, severe vomiting, diarrhea, obstruction of the urinary tract, or severe nephritis.

9. By what physical processes do solutes enter or leave the blood during dialysis?

During dialysis, waste solutes leave the blood and enter the dialysate through diffusion, moving from an area of high concentration to an area of low concentration. The dialysate is solute-free, creating a steep concentration gradient.

10. Why do blood and dialysate flow in opposite direction?

Blood and dialysate flow in opposite directions to maintain a constant concentration gradient for diffusion. This countercurrent exchange ensures that waste products continuously move from the blood into the dialysate, maximizing the efficiency of the filtering process.

11. Suggest two problems that might occur if the dialysate was pure water.

If the dialysate was pure water, it would cause excessive osmosis. Water would move from the dialysate into the blood, leading to a dangerous increase in blood volume and red blood cells would swell and burst (hemolysis), which could be fatal.

12. Why women are more likely to acquire UTI as compared to men?

Women are fifty times more likely to get UTIs than men because the female urethra is significantly shorter (1.5 inches) compared to the male urethra (8 inches). This makes it easier for bacteria from the anal region to travel to the bladder.

13. Write the differences between:

(a) osmoregulation and osmoconformers
Osmoregulation is the active process of maintaining a stable internal solute concentration. Osmoconformers are organisms whose internal solute concentration is the same as the external environment and thus they do not actively regulate it.

(b) ammonotelic and ureotelic
Ammonotelic animals excrete highly toxic ammonia and require large amounts of water (e.g., aquatic animals). Ureotelic animals excrete less toxic urea, requiring less water for excretion (e.g., mammals).

(c) ureotelic and uricotelics
Ureotelic animals excrete urea, which requires some water for excretion. Uricotelic animals excrete uric acid as a semi-solid paste, which requires very little water, making it ideal for dry environments (e.g., reptiles, birds).

(d) proximal and distal convoluted tubule
The proximal convoluted tubule is the first coiled part of the nephron where the majority of reabsorption of essential substances occurs. The distal convoluted tubule is the later coiled part where fine-tuning of ion and water balance occurs through hormonal action.

(e) afferent and efferent arterioles
The afferent arteriole carries blood to the glomerulus. The efferent arteriole carries blood away from the glomerulus. The efferent arteriole has a smaller diameter than the afferent, helping to create the high pressure needed for filtration.

(f) hypercalcemia and hyperuricemia
Hypercalcemia is an abnormally high level of calcium in the blood. Hyperuricemia is an abnormally high level of uric acid in the blood. Both can contribute to the formation of kidney stones.

(g) extracorporeal shock wave lithotripsy and percutaneous nephrolithotripsy
Extracorporeal shock wave lithotripsy (ESWL) uses shock waves from outside the body to break kidney stones. Percutaneous nephrolithotripsy (PCNL) is a more invasive procedure where an instrument is inserted through the back to break up larger stones.

(h) chronic renal failure and acute renal failure
Chronic renal failure is a gradual, irreversible loss of kidney function over years. Acute renal failure is a sudden, rapid decline in kidney function that can occur over a few hours or days.

(i) peritoneal dialysis and haemodialysis
Peritoneal dialysis uses the peritoneal membrane inside the abdomen as a natural filter. Haemodialysis uses an external machine with a dialyzer to filter the blood.

(j) renal cortex and renal medulla
The renal cortex is the outer, granular region of the kidney. The renal medulla is the middle region containing the renal pyramids. The cortex contains the glomeruli, while the medulla contains the loops of Henle.

(k) vasodilation and vasoconstriction
Vasodilation is the widening of blood vessels, which increases blood flow. Vasoconstriction is the narrowing of blood vessels, which decreases blood flow. These processes help regulate blood pressure and filtration rate in the kidney.

(l) dialyzer and dialysate
A dialyzer is the external filter or artificial kidney used in hemodialysis. Dialysate is the specialized fluid used in dialysis that attracts and removes waste products from the blood.

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