Escape From Al Catraz Quiz | Human Body

Quiz Answer Key and Fun Facts

1. Alan Catraz shook some salt onto an egg and gulped it down little realizing that one of the sodium atoms he ingested was the hapless hero of this quiz, Natrium the sodium ion (Nate to his friends). Helplessly carried along in the blood stream of his human host, Nate concocts a daring escape plan: he will contrive to be excreted into Al's urine. If he can remain in Al's blood stream, about how often how often will Nate pass through his host's kidneys?

Answer: Every 5 minutes

As long as Nate remains in the blood stream, he should pass through the kidneys every five minutes. I wonder why Nate hasn't escaped yet? After all, the kidneys receive 20% of the total cardiac output (even though they make up only 0.5% of the body weight) accounting for the fact that an amount equal to the total blood volume is flows through the kidneys every 5 minutes. Yet Nate's been in Alan's body for hours now! Of course, only about 15% of the blood plasma gets filtered into the tubes where urine is produced each time.

Stickler disclosures: Both this quiz and these stickler disclosures are meant to be tongue-in-cheek. You may want to refrain from sending fact based correction reports until you've read the stickler paragraph for the question in question. You don't think there are any actual people named "Catraz"? There is a "Catraz" kennel in Australia. I am confident there is at least a dog named "Al Catraz" if not a person. I also realize that sodium ions don't really have names and can't think. And yes, sodium ions would be constantly leaving the circulation through points other then the urinary tract. The amount of time a sodium ion could remain in a human's circulatory system without diffusing into some other part of the body is not readily available. So who knows? It might be as much as the time required for Nate to escape and for you to complete this quiz.

2. Nate the sodium ion floats free in the blood stream of his human host Alan Catraz, only sometimes passing through Al's kidneys. A portion of the fluid in which Nate floats gets sucked into the kidneys filtering mechanism the glomerulus where urine is produced each time he goes through the kidney. How often is Nate likely to be filtered into a glomerulus?

Answer: Less than a quarter of the time

Nate hopes to be filtered into one of Al's glomeruli. Then if he's lucky enough not to be reabsorbed, Nate will simply float out of Al in Al's urine. Even though only about 1/7th of the liquid portion of the blood minute flows into the glomeruli on each pass through the kidney, this means that an amount equal to the entire plasma volume is filtered through the kidney each hour! So, on the average, Nate should be filtered through a glomerulus once an hour. Yet, he's been there for hours and hours. Something must be countering his attempt to escape! (Hint, hint.)

Stickler disclosures: Sodium ions are not buoyant and can't float, but then this sodium ion has already been thoroughly anthropomorphized. This quiz ignores the fact that Nate could be secreted into the urine. Try not to think about it on every question. Finally, I understand that ions are, if anything, pushed into the glomeruli - but don't you think that scientific writing would be read a bit more often if the writers injected a little drama?

3. Nate the sodium ion, who is trapped in the blood stream of a human host, checks his watch. He's been ducking into the first portion of the urine forming tubules fairly frequently but keeps being sucked back into the blood stream. Often this happens in the looping first part of the tubule (loop of Henle). What is the name given to this process that keeps sucking Nate back?

Answer: Counter current mechanism

To make it through the microscopic tubules that come after the glomerulus and into the urine, Nate will have to navigate the u-shaped loop of Henle despite the dual threats of active molecular transport and passive diffusion. If Al's dehydrated, processes are activated that very efficiently reabsorb sodium and concentrate the urine. Hint: (Read the last four words of the next question very carefully.

Stickler disclosures: If the watch bothers you, you're going to go nuts when Nate starts talking to the other molecules.

4. Nate the sodium ion is often filtered into his host's renal tubules but usually gets reabsorbed in the proximal tubule. Even when he makes it to the distal convoluted tubule, he keeps getting sucked into cells that spit out a potassium ion in his place. Then Nate has to watch helplessly as the lucky potassium ion drifts away into the urine. Nate has heard that an evil sodium-conserving hormone is creating a concentration gradient that drives this process. Which of the following is it? (The gradient is like a flight of stairs where a group of sodium molecules can't even all do stair one.)

Answer: Aldosterone

Nate's chances for escaping the distal tubule depend a great deal on his host's state of hydration. Detecting dehydration, the wicked hormone Aldosterone pours out of the adrenal glands. Aldosterone stimulates renal sodium reabsorption and potassium excretion, not only in the distal convoluted tubules, but even in the tubules beyond. (Hint for next question)

Stickler disclosures: Aldosterone generally escapes moral censure. But wouldn't YOU think of Aldosterone as evil if you were in Nate's position? And it's true that it's imprecise to claim that Aldosterone "pours" out of the adrenal gland, but it is rapidly secreted in response to both dehydration and elevated blood potassium levels.

5. Trapped in the blood stream and trying to escape out the kidneys, Nate the sodium ion occasionally runs the circuitous gauntlet that the proximal and distal tubules pose and passes into the collecting tubule. Is the collecting tubule more likely to reabsorb Nate when levels of the sodium absorbing hormone that works on the distal convoluted tubules is present? (In other words, does the hormone work on both the distal convoluted and collecting tubules?)

Answer: Yes

The pernicious sodium reabsorbing hormone Aldosterone affects the collecting tubules as well as the distal convoluted tubules, further impeding Nate's ability to escape to the outside world.

Stickler disclosures: Regarding "pernicious", please see "stickler disclosure for question 4.

6. Nate the sodium ion remains trapped inside a human's blood stream hoping to escape through the human's kidneys. He meets a friendly serum protein named Alby Umin who seems confident he'll be leaving the body. Why should Nate be dubious about Alby's ability to get into the urine?

Answer: Proteins can't enter a normal glomerulus.

As blood serum whizzes past the glomerulus, larger molecules simply can't squeeze through the glomerular filter into the glomerular filtrate - unless of course, the glomerular membrane is damaged. Even a disease-ridden glomerulus usually stops larger proteins such as globulins, but smaller proteins like Alby Umin (albumin) are able to pass into the glomerular filtrate and ultimately escape into the urine.

Stickler disclosures: If an ion can have a name, think and speak, why not a protein molecule. And yes, "whizzes" was intended to be a pun, albeit a sad one.

7. Alby Umin the protein has told Nate the sodium molecule of his plans to escape the body through Alan Catraz's kidney. "Our host Catraz," Alby explains, "has a kidney disease that allows proteins like me to pass into the urine." What name does Alby say humans give this condition?

Answer: Both

Even a diseased glomerulus is likely to prevent the escape of larger proteins such as globulins. In fact, because it is mainly the relative small protein albumin that passes into the urine in patients with glomerular disease, both the term "albuminuria" and the term "proteinuria" are used to describe the abnormality.

Now new "stickler disclosures" for this question.

8. If only Nate the sodium ion could ride out of his host's kidney attached to Alby the albumin molecule! But what keeps Nate from riding with Alby?

Answer: All of these

Albumin molecules have no charge or binding sites to allow binding ions like Nate. But couldn't Nate find some different sort of molecule he could attach himself to and simply ride to freedom? "Drugs" Nate thought with a shudder. Nate's mom always warned him not to get involved with drugs. "You'll think it's just an ionic attachment and find yourself covalently bound," she warned.

Stickler disclosure: No sodium ion is known to have passed a course in chemistry. Also, I realize that a molecule would not be able to choose what to bind to.

9. Attached to a drug molecule, Nate the sodium ion escaped from Al Catraz... or at least a kidney belonging to Alan Catraz. Nate now finds himself hurtling down a narrow tube. Having just left the kidney, in what structure is Nate now?

Answer: Ureter

The urine formed in the microscopic urinary tubules eventually finds its way into the roughly triangular shaped renal pelvis. After passing through the ureter, the exhausted Nate comes at last, nearly prostrate, to the bladder.

Stickler disclosure: Flow rates in the ureter would hardly justify the description of "hurtling". Nate's extremely small size would make the ureteral stream seem a vast river indeed. I drew a kindly veil over the details of the matter of Nate's temporary attachment to a drug.

10. Having reached the bladder of Alan Catraz, Nate has almost made good his escape from his host's urinary tract. As the bladder empties, the urine flow stops and starts. Just as he leaves the bladder, Nate sees a huge mound pressing into the urinary tract. What organ is this likely to be?

Answer: Prostate

Flushed with excitement, Nate flows happily into a sewer under Al Catraz's house. From there he plans to journey into the San Francisco Bay and freedom.

Stickler disclosure: Bladder outlet obstruction is, of course, a complicated matter involving not only the prostate's obstruction of the urethra but also reactive hypertrophy of the bladder and the musculature of the outflow tract resulting in the classic triad of symptoms: hesitancy, intermittency and dribbling.

Source: Author uglybird

This quiz was reviewed by FunTrivia editor crisw before going online.
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Escape From Al Catraz Trivia Quiz

Nate the sodium ion is trapped in the body of Alan Catraz. Can you help him escape? (Best played in "Flash" mode since interesting information may include clues to answers of subsequent questions.)

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