what is the answer?

[laya533]

"Some animals are known to have the ability of skin respiration. Humans cannot do this becuase human skin is"
I. too thick
II. too dry.
II.capillary

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[MoosePilot]

"Some animals are known to have the ability of skin respiration. Humans cannot do this becuase human skin is"
I. too thick
II. too dry.
II.capillary

Hmmm...

I'd eliminate III., because if I wanted skin respiration, I'd probably design it with a capillary bed beneath a thin moist membrane.

At that point I'd go 50/50. My guess would be II, too dry, but this is really a stupid question. Where did you get it from?

 

[N-toxicologist]

http://www.scientia.org/cadonline/Biology/respiratory/respiration.ASP

....In order to perform these two functions, the human respiratory system must meet the four basic needs common to all aerobic respiratory systems: 1) It must provide a large enough respiratory surface to take in enough oxygen for all the cells of an individual; 2) it must provide a method of transporting gases between the area of exchange with the outside environment and the internal cells; 3) it must protect the exchange surface from mechanical injury; and 4) it must keep the exchange surface moist so that gases can diffuse into solution and be absorbed by the body.

Compare your lungs and your skin at this point:
1)surface area: skin has lots; moving on
2)method of transport: capillary system (skin has it)
3)protect: yes (thick)
4) moisture: nope. My guess is "too dry"

I guess you could compare your skin to a frog's, too

 

[Daichi Katase]

so it is I and II? (well...the first II)

 

[Amorphisgirl]

I'd go with II, dry skin. All of our outer skin cells are dead. Contrast with frogs, which have pulmocutaneous circulation (some respiration through skin).

 

[laya533]

this "stupid question" is from April 2004 MCAT.!!!!

 

[N-toxicologist]

this "stupid question" is from April 2004 MCAT.!!!!

I have no idea how you remembered that.

I couldn't remember where I parked my car after the April MCAT!

 

[MoosePilot]

this "stupid question" is from April 2004 MCAT.!!!!

Really? Then was there an option I and II?

 

[aamartin81]

Animals that use moist skin as a respiratory surface exchange gases by simple diffusion. The skin of humans is both too thick and too dry to accomodate diffusion of gases. As mentioned earlier, thin skin with a capillary bed would aid skin respiration. The answer is I and II.

ADam

 

[Prophecies]

As a reminder, you should've learned this in general biology: cutaneous respiration (or any respiration for that matter) can only occur if the membrane (skin) is thin, moist, and well-vascularized.

 

[Shrike]

this "stupid question" is from April 2004 MCAT.!!!!

No, it isn't quite. I remember this question; the question itself and the first two choices are approximately what was there, but the third is not. Also, the question stem on the MCAT specifically mentioned the walking catfish, if I recall correctly.

Unfortunately, I don't remember what the analog of your choice III was (I memorized that test, but it was a while ago); I know it was similar to what you wrote, but the statement made somewhat more sense than it does as you've written it. (If it had been a reasonable choice, however, I'd probably remember it; apparently it was easy to dismiss.)

 

[liverotcod]

I memorized that test

Shrike, you're a strange person. Not in a bad way, you understand, but still.

 

[laya533]

Shrike, I have heard it from others who took it. I just wanted to let the others know about that. they can probably figureout the III in the test. I just wanted to have a general concept for answering that. Any argues with that?

 

[Shrike]

I am not arguing, I am pointing out that the wording on the test differed from what you wrote, and by extension that that difference may affect people's reactions to the question. I agreed that the concept was present. In effect, I backed you up.

 

[Shrike]

Shrike, you're a strange person. Not in a bad way, you understand, but still.

Hey, maybe in a bad way, too. You don't know.

Yes, I am aware that I'm a bit unusual.

 

[laya533]

OK. In that case , my mistake. and thanks for backing me up.

 

[N-toxicologist]

Shrike, you're a strange person. Not in a bad way, you understand, but still.

You have no idea......

Yes, I am aware that I'm a bit unusual.

This is both accurate, and an understatement.

Hello, BTW. Nice to see you.

 

[Turkeyman]

Yeah I was thinking what aamartin and Prophecies were thinking...the layer has to be thin as well, think alveoli.....SUPER thin.

I and II.