MSN Exam for Excretory System

Text Mode – Text version of the exam

Questions

1. Nurse Logan was making her rounds in the nephrology ward, carefully monitoring the progress of her patients undergoing dialysis. She needed to explain the intricacies of the renal system to one particularly inquisitive patient, including the formation of the juxtaglomerular apparatus in the kidney. She phrased her question thus:

“In the kidney’s complex system, juxtaglomerular cells intertwine with which other cells to create the juxtaglomerular apparatus?”

A. Cells from the renal sinus.
B. Cells from the renal pelvis.
C. Macula densa cells.
D. Nephron cells.

2. While reviewing her notes on renal circulation, nurse Emily contemplates the journey of a blood cell through the kidney, from the renal artery to the renal vein. She wonders, which among the following doesn’t belong in this intricate vascular route?

A. Glomerulus
B. Peritubular capillaries
C. Efferent arteriole
D. Pulmonary artery

3. In the middle of a night shift, Nurse Emma found herself sharing a cup of coffee with an intern who was studying for his exams. To test his understanding of renal anatomy, she posed a question:

“What type of tissue forms the composition of the renal medulla in our kidneys?”

A. The renal pelvis.
B. Nephrons
C. Renal pyramids.
D. The renal sinus.

4. During a health promotion event, Nurse Liam was explaining kidney function to a group of high school students. To illustrate the topic of urine composition, he posed an intriguing question:

“Out of these substances, which one do you think is present in the highest concentration in our urine?”

A. Urea
B. Uric acid
C. Creatinine
D. Glucose

5. While working in the nephrology clinic, Nurse Harper decided to quiz a medical student on renal physiology. She pointed towards a model of the nephron and asked:

“What is the key role performed by the ascending loop of Henle within the kidneys?”

A. It actively reabsorbs sodium.
B. It passively reabsorbs potassium.
C. It passively reabsorbs urea.
D. It actively reabsorbs nitrates.

6. In the urology department, Nurse Maddison was helping a patient understand the structure of the urinary bladder in preparation for an upcoming procedure. She crafted her question in a clear and concise manner:

“What is the term for the middle layer found in the urinary bladder?”

A. Muscular Coat
B. Submucous Coat
C. Sphincter Coat
D. Mucous Coat

7. During a patient’s check-up in the urology clinic, Nurse Anderson was explaining the micturition process, which sparked a conversation about the neural control of urination. He posed a question to clarify:

“Can you tell me where the micturition reflex center is located in our bodies?”

A. Lumbar plexus
B. Pons
C. Midbrain
D. Sacral plexus

8. In a community health seminar about kidney health, Nurse Spencer had been explaining various terms related to urinary output. He posed a question to engage the audience:

“Could you tell me which term corresponds to the condition characterized by a low production of urine?”

A. Enuresis
B. Diuresis
C. Oliguria
D. Pyuria

9. While guiding a group of nursing students through the nephrology ward, Nurse Reed used a diagram of a nephron to illustrate the various renal functions. As part of her lesson, she asked:

“What’s the main function of the descending loop of Henle in the kidney?”

A. The secretion of potassium ions.
B. The reabsorption of water by osmosis.
C. The reabsorption of sodium ions.
D. The secretion of hydrogen ions.

10. In the middle of her shift in the nephrology department, Nurse Ava decided to challenge a medical intern on his knowledge of renal microanatomy. She asked:

“The capillary loops found within the medulla of the kidney are referred to as what?”

A. Trigone
B. Urea collectors
C. Macula densa
D. Vasa recta

11. During a health teaching session about male urinary anatomy in a men’s health clinic, Nurse Jason posed a question to the group to gauge their understanding:

“Which of the following is not considered a segment of the male urethra?”

A. Penile
B. Membranous
C. Vasapore
D. Prostatic

12. In a diabetes education seminar, Nurse Grace was explaining the impact of high blood sugar levels on kidney function. She posed a question to her audience to highlight one possible outcome:

“When glucose is detected in the urine, what is this condition called?”

A. Glucose intolerance
B. Uremia
C. Glucosuria
D. Ureteritis

13. During a busy afternoon shift, nurse Callum carefully reviews the medications for his patient suffering from fluid overload. He examines the list of prescribed drugs and wonders: which one among these is not a loop diuretic?

A. The reliable Furosemide (LASIX).
B. The potent Ethacrynic Acid (EDECRIN).
C. The mild Chlorothiazide (DIURIL).
D. The compact Bumetanide (BUMEX).

14. Late into the night, nurse Aurora is immersed in her studies, exploring the intricacies of renal function. She ponders over the role of the distal convoluted tubule in the kidneys. Is it responsible for:

A. Production of urine through filtration.
B. Reabsorption of water and sodium ions.
C. Oxygen and carbon dioxide exchange.
D. Breaking down food into nutrients.

15. In the heart of a busy ICU, nurse Grace is caring for a patient with electrolyte imbalance. While adjusting the IV fluid rate, she reflects on the impact of ADH on the distal convoluted tubule. Does it:

A. Reduce water reabsorption.
B. Lower the concentration of urine.
C. Heighten water reabsorption.
D. Expand the urine volume.

16. In the calm of the early morning, nurse Rafael is preparing for a lecture on renal physiology to the nursing students. As he sips his coffee, he reflects on a query related to the multifaceted role of the kidneys. Which function is not attributed to them?

A. The discharge of renin, a significant enzyme.
B. The emission of Vitamin E.
C. The activation of Vitamin D.
D. The production of erythropoietin, a crucial hormone.

17. Nurse Amelia, renowned for her expertise in urology, is discussing kidney stones with her patient. In the middle of their conversation, she reflects on the composition of these troublesome deposits. Which substance isn’t typically found in kidney stones?

A. The stubborn Uric Acid.
B. The notorious Calcium oxalate.
C. The modest HCO3.
D. The persistent Calcium phosphate.

18. Amidst the busy telemetry unit, nurse Elliot is caring for a patient with hypertension. As he monitors the patient’s blood pressure, he recalls the impact of Angiotensin II release. What does this potent hormone trigger?

A. The drop in glomerular hydrostatic pressure.
B. The surge in filtration rate.
C. The boost in Vitamin E synthesis.
D. The heightened release of erythropoietin.

19. In a quiet corner of the hospital’s pharmacy, nurse Lucas reviews a patient’s prescription. He considers the effects of a diuretic medication that the patient is prescribed. What is a likely consequence of this drug?

A. Augmentation in sodium reabsorption.
B. Reduction in Cardiac Output.
C. Amplification of chloride ion reabsorption.
D. Surge in fluid volume.

20. During her anatomy and physiology lecture, nurse Zoey marvels at the incredible complexity of the human body. She ponders about the kidneys, specifically, how many nephrons, the working units, each kidney approximately houses. Is it:

A. 100,000
B. 10,000
C. 10 million
D. 1 million

Answers and Rationales

1. Correct answer:

C. Macula densa cells. The juxtaglomerular apparatus is a specialized unit in the kidneys that regulates the function of each nephron, the fundamental functional unit of the kidney. It comprises three types of cells: juxtaglomerular cells, macula densa cells, and extraglomerular mesangial cells. Among these, juxtaglomerular cells and macula densa cells intertwine to form a significant portion of this structure. Juxtaglomerular cells, which secrete renin, are located in the walls of the afferent arterioles. Macula densa cells are specialized cells in the distal convoluted tubule that detect sodium chloride levels and signal to the juxtaglomerular cells to release renin if necessary. This relationship is crucial for maintaining blood pressure homeostasis and electrolyte balance.

A practical analogy could be a sophisticated thermostat system where the macula densa cells serve as the ‘temperature detector’ and the juxtaglomerular cells as the ‘controller’ that turns on the ‘heating’ (releases renin) when ‘temperature’ (sodium chloride levels) gets too low.

Incorrect answer options:

A. Cells from the renal sinus. The renal sinus is a cavity within the kidney that is occupied by part of the renal pelvis, renal calices, blood vessels, nerves, and fat. It doesn’t directly contribute to the formation of the juxtaglomerular apparatus.

B. Cells from the renal pelvis. The renal pelvis is a funnel-shaped space in the kidney that collects urine from the renal calyces and funnels it into the ureters. It plays no role in the composition of the juxtaglomerular apparatus.

D. Nephron cells. This option is too broad. The nephron is the basic functional unit of the kidney, consisting of the glomerulus, proximal tubule, loop of Henle, and distal tubule. While the macula densa is part of the nephron, not all cells in the nephron contribute to the formation of the juxtaglomerular apparatus.

2. Correct answer:

D. Pulmonary artery. The pulmonary artery is not part of the renal circulation pathway. The blood cell journey through the kidney starts when blood enters via the renal artery. From there, blood proceeds to smaller and smaller arteries, until it reaches the afferent arteriole which leads into the glomerulus. This is a network of capillaries where filtration occurs. Blood then leaves the glomerulus via the efferent arteriole, which further branches out into the peritubular capillaries that surround the nephrons (the functional units of the kidneys). These capillaries reabsorb necessary substances from the filtrate back into the bloodstream, then eventually combine into larger and larger veins until they form the renal vein, which carries blood away from the kidney.

Imagine the renal circulation like a city’s water treatment plant. The renal artery is the main pipe that brings water into the plant. The water then goes through several processing units (glomerulus) for filtration, the waste is removed, and the clean water (efferent arteriole) is directed into further pipes (peritubular capillaries) for additional cleaning and reabsorption of necessary substances. The treated water then exits the plant through an outflow pipe (renal vein). The pulmonary artery, in this case, would be like a power line – essential for the city’s operations but not directly involved in the water treatment process.

Incorrect answer options:

A. Glomerulus. This is an integral part of the renal circulation, where blood is initially filtered.

B. Peritubular capillaries. These are also a crucial part of the renal circulation, allowing for the reabsorption of necessary substances from the filtrate back into the blood.

C. Efferent arteriole. This carries blood out of the glomerulus and branches into the peritubular capillaries, so it is also part of the renal circulation.

3. Correct answer:

C. Renal pyramids. The renal medulla of the kidneys is primarily composed of renal pyramids. These cone-shaped structures are essentially the ‘factories’ of urine production. They contain portions of the nephrons, specifically the loops of Henle and collecting ducts, which play critical roles in the reabsorption and secretion processes that regulate water and electrolyte balance. The tips of the renal pyramids, known as renal papillae, point inward towards the renal pelvis.

Think of the renal pyramids as office buildings in a city (the kidney). These ‘buildings’ are filled with ‘workers’ (nephrons) that each play a part in the production line, ultimately creating a finished product (urine).

Incorrect answer options:

A. The renal pelvis. This is the funnel-shaped structure in the kidney where urine collects before passing into the ureter and then the bladder. It’s not a type of tissue but an anatomical feature, like a city’s main transit hub where finished products (urine) are sent for distribution (excretion).

B. Nephrons. Nephrons are the functional units of the kidney, not a type of tissue. They are akin to the ‘workers’ in our city analogy, doing the actual work of filtering blood and producing urine.

D. The renal sinus. This is a cavity within the kidney that houses the renal pelvis, calyces, blood vessels, and fat. It’s like the land the city (kidney) is built on but not an actual ‘building’ (tissue type) itself.

4. Correct answer:

A. Urea. Urea is the substance present in the highest concentration in normal urine. It is a waste product of protein metabolism and is produced in the liver. The kidneys then filter urea out of the blood and excrete it in urine. It represents roughly 50% of the total solids in urine.

To illustrate this, think of urea as the most common type of trash in a city’s waste management system. Just like the trash, urea needs to be regularly removed from the body to prevent a buildup of waste.

Incorrect answer options:

B. Uric acid. This is a waste product from the metabolism of purines, which are part of many foods and all of your body’s cells. While it is normally present in urine, its concentration is much lower than that of urea.

C. Creatinine. This is a waste product produced by muscles from the breakdown of a compound called creatine. Creatinine is removed from the body by the kidneys, which filter almost all of it from the blood to be excreted in urine. However, its concentration in urine is less than that of urea.

D. Glucose. In a healthy individual, glucose should not be present in the urine. The kidneys normally reabsorb all glucose and return it to the bloodstream while they are filtering blood to form urine. If there is glucose in the urine, it typically means that the blood glucose level is too high, which can be a sign of diabetes.

5. Correct answer:

A. It actively reabsorbs sodium. The thick segment of the ascending loop of Henle is responsible for the active reabsorption of sodium, as well as other ions like potassium and chloride. This active reabsorption process is driven by a type of protein called a “sodium-potassium pump”. As sodium is transported out of the filtrate, other substances follow due to the osmotic gradient created, contributing to the concentration of the urine.

Think of the ascending loop of Henle as a waste management facility that uses special equipment (the sodium-potassium pumps) to sort through and recover valuable materials (sodium, potassium, chloride) before the remaining waste is removed from the facility.

Incorrect answer options:

B. It passively reabsorbs potassium. This is not correct because the potassium reabsorption in the ascending loop of Henle is actually active, not passive, and is coupled with the active reabsorption of sodium.

C. It passively reabsorbs urea. The urea reabsorption mainly happens in the inner medullary collecting duct, not in the ascending loop of Henle.

D. It actively reabsorbs nitrates. Nitrates are not a major constituent of urine or a significant part of the reabsorption process in the kidneys.

6. Correct answer:

B. Submucous Coat. The urinary bladder wall is composed of three main layers: the innermost mucous coat (or urothelium), the middle submucous coat, and the outer muscular coat (also known as the detrusor muscle). The submucous coat is composed of dense irregular connective tissue and houses blood vessels, nerves, and lymphatic vessels. This layer provides flexibility and elasticity to the bladder, allowing it to expand as it fills with urine and contracts during urination.

An analogy for this might be thinking of the urinary bladder as a balloon. The inner mucous coat would be like the inside surface of the balloon that comes in contact with the air (or urine, in the bladder’s case), the submucous coat is like the flexible rubber material of the balloon that allows it to expand and contract, and the muscular coat is like the outer surface of the balloon.

Incorrect answer options:

A. Muscular Coat. This is the outermost layer of the bladder and consists of smooth muscle known as the detrusor muscle. It contracts during urination to expel urine but isn’t the middle layer.

C. Sphincter Coat. There’s no layer called the “sphincter coat” in the bladder. However, at the junction of the bladder and urethra, there are internal and external urethral sphincters that control the release of urine.

D. Mucous Coat. This is the innermost layer of the bladder, lining the hollow lumen where urine is stored. It’s not the middle layer.

7. Correct answer:

B. Pons. The micturition reflex center is located in the pons, a part of the brainstem. This area, also known as the pontine micturition center or Barrington’s nucleus, coordinates the process of micturition (urination). When the urinary bladder is sufficiently full, stretch receptors in the bladder wall send signals to the brain. The pons then integrates this information and sends signals back to the bladder via parasympathetic nerves, initiating contraction of the bladder’s detrusor muscle and relaxation of the internal urethral sphincter, leading to urination.

You might think of the pons as the control center in a factory. When a container in the factory is full (the bladder), a signal is sent to the control center (pons), which then gives the command to empty the container (urinate).

Incorrect answer options:

A. Lumbar plexus. This is a network of nerve fibers in the lumbar region of the body, supplying muscles and skin of the lower abdomen and legs. It is not associated with the control of micturition.

C. Midbrain. The midbrain, or mesencephalon, is a part of the brain located above the pons and contains various nerve pathways. However, it is not where the micturition reflex center is located.

D. Sacral plexus. This is a nerve plexus located in the pelvis, which provides motor and sensory nerves for the posterior thigh, most of the lower leg and foot, and part of the pelvis. While the parasympathetic fibers that control the bladder originate in the sacral region of the spinal cord, the reflex center for micturition itself is located in the pons.

8. Correct answer:

C. Oliguria. Oliguria is the medical term that refers to the production of abnormally small amounts of urine. It’s generally defined as a urine output of less than 400 milliliters (or less than 500 to 600 mL according to some references) in 24 hours in adults. It can be a symptom of dehydration, kidney dysfunction, or urinary tract obstruction among other possible causes.

To make it more relatable, consider a scenario where a city’s water supply (representing the blood supply to the kidneys) is reduced due to a drought (e.g., dehydration or other causes). Consequently, the output from the city’s water treatment plant (the kidneys) would be reduced, just like the low urine output in oliguria.

Incorrect answer options:

A. Enuresis. This is the term for involuntary urination, especially by children at night, also known as bedwetting. It does not refer to the volume of urine produced.

B. Diuresis. This term refers to the increased or excessive production of urine. It is the opposite of oliguria. Diuresis can be caused by various factors, such as certain medications (diuretics), high fluid intake, or certain medical conditions.

D. Pyuria. This term refers to the presence of pus in the urine, indicating urinary tract infection or other medical conditions. It’s not about the volume of urine produced but rather its quality.

9. Correct answer:

B. The reabsorption of water by osmosis. The primary function of the descending loop of Henle in the nephron of the kidney is the reabsorption of water. The descending loop is permeable to water but not to most solutes, so water passively moves out of the loop and into the hyperosmotic medullary interstitial fluid. This process concentrates the filtrate as it moves towards the bend of the loop.

The descending loop of Henle acts much like a sponge left in a puddle of water. The sponge (loop of Henle) passively absorbs the water (from the filtrate) into its matrix (the medullary interstitial fluid).

Incorrect answer options:

A. The secretion of potassium ions. While the kidneys do regulate potassium balance in the body, the primary location for this is not the descending loop of Henle, but the distal convoluted tubule and the collecting ducts.

C. The reabsorption of sodium ions. This primarily occurs in the ascending loop of Henle, which is permeable to ions like sodium, chloride, and potassium, but impermeable to water.

D. The secretion of hydrogen ions. This primarily takes place in the proximal convoluted tubule, distal convoluted tubule, and collecting ducts, which play crucial roles in maintaining acid-base balance. The descending loop of Henle is not primarily involved in this process.

10. Correct answer:

D. Vasa recta. The vasa recta are the capillary loops in the medulla of the kidney. They are the blood vessels that descend from the efferent arterioles of the juxtamedullary nephrons (those nephrons close to the medulla), and they play a crucial role in maintaining the medullary concentration gradient, a key mechanism that the kidneys use to concentrate the urine and conserve water.

Consider the vasa recta as the dedicated delivery trucks on a factory production line (the nephron). These trucks (vasa recta) bring the necessary supplies (blood with oxygen and nutrients) directly to the factory workers (the cells in the medulla) who need them to function effectively.

Incorrect answer options:

A. Trigone. This is a triangular area seen on the internal urinary bladder. It is marked by the two ureteral orifices and the internal urethral orifice, but it does not refer to any structures within the kidney itself.

B. Urea collectors. This is not a term used in renal physiology or anatomy. Urea, a waste product, is collected and concentrated in the renal tubules, but there’s no structure specifically known as “urea collectors.”

C. Macula densa. This refers to a group of specialized cells in the distal convoluted tubule that detect changes in fluid electrolyte concentration and flow rate. They are a part of the juxtaglomerular apparatus and help regulate blood pressure, but they are not capillary loops.

11. Correct answer:

C. Vasapore. There is no segment of the male urethra known as the “Vasapore.” The male urethra, which carries urine from the bladder and semen from the reproductive system to the exterior of the body, is divided into three segments: the prostatic urethra, the membranous urethra, and the penile (or spongy) urethra.

Think of the male urethra like a highway with three major sections. There are well-defined and recognizable parts (the prostatic, membranous, and penile segments), but “Vasapore” would be like an exit or landmark that doesn’t exist on this highway.

Incorrect answer options:

A. Penile. Also known as the spongy urethra, this is the longest segment of the urethra that runs through the corpus spongiosum of the penis to the external urethral orifice.

B. Membranous. This is the shortest and least dilatable part of the male urethra, which traverses the urogenital diaphragm (a layer of the pelvic floor).

D. Prostatic. This is the widest and most dilatable part of the urethra, which traverses the prostate gland.

12. Correct answer:

C. Glucosuria. Glucosuria refers to the presence of glucose in the urine. Normally, glucose is reabsorbed in the proximal convoluted tubule of the nephron in the kidneys, but when the blood glucose levels are excessively high (as in uncontrolled diabetes), the renal threshold for glucose is exceeded and it starts to appear in the urine.

To illustrate, imagine the kidney’s tubules as a very efficient recycling facility that wants to keep as much sugar (glucose) as possible. When there is too much sugar delivered (high blood sugar levels), the facility gets overwhelmed, and some sugar slips past and ends up in the urine (glucosuria).

The medical term “glucosuria” can be broken down as follows:

Gluc/o: This root word is derived from the word “glucose,” which is a type of sugar found in the blood. It refers to the sugar component of the term.
-uria: This suffix means “urine.” It is used to describe a condition or presence of a substance in the urine.

Incorrect answer options:

A. Glucose intolerance. This term refers to abnormal blood glucose responses, such as impaired fasting glucose or impaired glucose tolerance, but it does not directly imply the presence of glucose in the urine.

B. Uremia. This refers to a high concentration of urea and other nitrogenous waste products in the blood due to renal failure. It is not related to glucose levels in the urine.

D. Ureteritis. This refers to inflammation of the ureters, which are the tubes that carry urine from the kidneys to the bladder. It does not indicate the presence of glucose in the urine.

13. Correct answer:

C. Chlorothiazide (DIURIL). Chlorothiazide is a thiazide diuretic, not a loop diuretic. Thiazides act primarily on the distal convoluted tubule in the nephron to inhibit sodium reabsorption, which leads to increased urine output. This helps to lower blood pressure and reduce fluid overload, but it is typically less potent than the loop diuretics.

Think of diuretics as different types of sponges that you can use to mop up a water spill (the “spill” being the excess fluid in the body). Furosemide, ethacrynic acid, and bumetanide are like super-absorbent sponges (loop diuretics) that can soak up a lot of water very quickly, while chlorothiazide is more like a regular kitchen sponge (a thiazide diuretic) that is less absorbent.

Incorrect answer options:

A. Furosemide (LASIX). Furosemide is a loop diuretic. It acts on the ascending loop of Henle in the kidney to inhibit sodium, potassium, and chloride reabsorption, leading to significant diuresis.

B. Ethacrynic Acid (EDECRIN). This is also a loop diuretic and works in a similar way to furosemide.

D. Bumetanide (BUMEX). Bumetanide is another loop diuretic. It is even more potent than furosemide and works on the same site in the kidney.

14. Correct answer:

B. Reabsorption of water and sodium ions. The distal convoluted tubule (DCT), a part of the nephron within the kidney, primarily plays a role in the reabsorption of water and sodium ions, amongst other electrolytes. This segment of the nephron is responsive to antidiuretic hormone (ADH) and aldosterone, hormones that help regulate fluid balance and blood pressure.

Imagine the DCT as a meticulous quality checker in a factory (the kidney). After initial processing (filtration in glomerulus, reabsorption, and secretion in proximal convoluted tubule and loop of Henle), the product (the filtrate or pre-urine) goes through this last quality check, where the final adjustments are made. If the body needs more water or sodium, the DCT reabsorbs them back into the bloodstream.

Incorrect answer options:

A. Production of urine through filtration. The initial urine production through filtration occurs in the glomerulus, not the distal convoluted tubule.

C. Oxygen and carbon dioxide exchange. Oxygen and carbon dioxide exchange primarily happens in the lungs, not the kidneys or the distal convoluted tubule.

D. Breaking down food into nutrients. The process of breaking down food into nutrients occurs in the digestive system, specifically the stomach and small intestines, not in the kidneys or the distal convoluted tubule.

15. Correct answer:

C. Heighten water reabsorption. Antidiuretic hormone (ADH), also known as vasopressin, acts on the kidneys to increase water reabsorption. It primarily acts on the collecting ducts of the nephrons (and to a lesser extent on the distal convoluted tubules), making them more permeable to water. As a result, more water is reabsorbed into the bloodstream, reducing urine volume and concentrating the urine.

Consider ADH as a manager in a water bottling plant (your kidney). When the manager sees that water supplies are running low (low body water level), he orders the factory workers (the DCT and collecting ducts) to save as much water as possible, leading to less water being packaged and sent out (lower urine volume).

Incorrect answer options:

A. Reduce water reabsorption. This is the opposite of what ADH does. ADH promotes water reabsorption, not reduction.

B. Lower the concentration of urine. Again, this is opposite to the action of ADH. The reabsorption of water back into the bloodstream under the influence of ADH results in more concentrated urine, not less.

D. Expand the urine volume. This is not correct. ADH leads to a decrease in urine volume because it promotes water reabsorption from the urine back into the blood.

16. Correct answer:

B. The emission of Vitamin E. The kidneys do not produce or secrete vitamin E. This vitamin is typically obtained from dietary sources and is essential for numerous biological functions, including boosting the immune system, widening blood vessels, and inhibiting blood clotting. However, it’s not within the kidneys’ repertoire of functions to produce this vitamin.

The kidneys have many crucial roles akin to a super-efficient waste management system. In addition to filtering waste products and excess substances from the blood, they also regulate blood pressure, red blood cell production, and balance electrolytes. But producing vitamin E isn’t on their job list.

Incorrect answer options:

A. The discharge of renin, a significant enzyme. This is true. The kidneys release the enzyme renin as part of the Renin-Angiotensin-Aldosterone System (RAAS), a key regulator of blood pressure.

C. The activation of Vitamin D. This is correct. The kidneys play a key role in the conversion of inactive vitamin D into its active form, calcitriol. This active form of Vitamin D helps regulate calcium and phosphate balance in the body, which is crucial for bone health.

D. The production of erythropoietin, a crucial hormone. This is accurate. The kidneys produce erythropoietin, a hormone that stimulates the production of red blood cells in the bone marrow. This is a critical function, especially in conditions where oxygen levels in the blood are low.

17. Correct answer:

C. The modest HCO3. Bicarbonate (HCO3) is not typically a component of kidney stones. It’s an essential part of the body’s buffering system that maintains blood pH. Kidney stones are generally formed from substances that crystallize in the urine, such as calcium (in combination with oxalate or phosphate), uric acid, and cystine.

In a simplified analogy, if we consider our body as a factory and kidneys as waste management units, HCO3 acts like a regulator maintaining the cleanliness and acidity of the factory environment, but it doesn’t turn into waste (kidney stones).

Incorrect answer options:

A. The stubborn Uric Acid. This is not correct. Uric acid can indeed form kidney stones, particularly in people with gout or those undergoing chemotherapy.

B. The notorious Calcium oxalate. This is also incorrect. Calcium oxalate stones are the most common type of kidney stone.

D. The persistent Calcium phosphate. Again, this is not correct. Calcium phosphate can combine with other substances to form kidney stones.

18. Correct answer:

B. The surge in filtration rate. Angiotensin II has a complex role in renal physiology. It’s a potent vasoconstrictor, primarily constricting efferent arterioles more than afferent arterioles in the glomerulus. This vasoconstriction of the efferent arterioles increases the hydrostatic pressure in the glomerulus, thereby increasing the glomerular filtration rate (GFR).

This is analogous to tightening the end of a garden hose – the water inside the hose (blood within the glomerulus) has nowhere to go but out, thus increasing the pressure and forcing more water (filtrate) out.

Incorrect answer options:

A. The drop in glomerular hydrostatic pressure. This is incorrect because angiotensin II actually tends to increase glomerular hydrostatic pressure, as explained above, thus promoting filtration.

C. The boost in Vitamin E synthesis. This is incorrect as angiotensin II doesn’t have any known effect on Vitamin E synthesis. Vitamin E is obtained through the diet and is not synthesized in the body.

D. The heightened release of erythropoietin. This is also incorrect. While angiotensin II does stimulate the release of erythropoietin, this is not its primary action. The primary role of angiotensin II is in the regulation of blood pressure and electrolyte balance.

19. Correct answer:

B. Reduction in Cardiac Output. Diuretics work by increasing the amount of water and salt expelled by the body as urine. By removing fluid from the bloodstream, they reduce the volume of blood that the heart has to pump, thereby reducing cardiac output.

It’s similar to lightening the load on a truck – the less it has to carry, the less power it needs to drive.

Incorrect answer options:

A. Augmentation in sodium reabsorption. This is incorrect. Diuretics, by their nature, aim to increase sodium excretion, not reabsorption. They do this by blocking the reabsorption of sodium in the kidneys, leading to more sodium being expelled in the urine. More sodium in the urine draws more water into the urine, increasing the amount of urine produced.

C. Amplification of chloride ion reabsorption. This is incorrect. Some diuretics (like loop and thiazide diuretics) actually increase the excretion of chloride ions in the urine, not their reabsorption. This is because they inhibit sodium reabsorption in the kidney tubules, and chloride ions usually follow sodium due to their electrical attraction.

D. Surge in fluid volume. This is also incorrect. The primary purpose of diuretics is to reduce fluid volume in the body. They do this by increasing the volume of urine produced, thus removing more water from the body.

20. Correct answer:

D. 1 million. Each human kidney contains approximately 1 million nephrons, the basic functional units of the kidney. Each nephron is responsible for the filtration and purification of blood, reabsorption of needed substances, and excretion of waste products through urine.

To visualize it, think of a gigantic city with about a million households, where each house (nephron) plays a critical role in maintaining the city’s (kidney’s) function.

Incorrect answer options:

A. 100,000. This is incorrect. The number of nephrons in each kidney far exceeds this figure. This is akin to significantly underestimating the population of a major city.

B. 10,000. This is also incorrect. Similar to option A, this figure dramatically underestimates the number of nephrons present in each kidney. It’s like undercounting the number of trees in a large forest.

C. 10 million. While this number is impressive, it is an overestimation of the number of nephrons in each human kidney. This would be like counting extra, non-existent houses in our city analogy.