>> At least I didn't say it was through the aorta. (That, of course, 
>> would be the way *from* the heart, not *to* it.) I bothered to get 
>> that much right. ;-)
> 
> yes and no ;) Blood exits the heart via the aorta, but it used to be the 
> standard entry point for catheters if you wanted to go to the left 
> ventricle (where many arrhythmias originate).

Heh. I don't know if it's a rule of the Internet, but it probably should 
be: For any conceivable topic, somebody else will know way, way more 
about it than you. :-}

I would have thought trying to enter against the flow of blood through 
the single largest blood vessel in the entire human body would be quite 
difficult - then again, I'm sure many people far more knowledgeable than 
me have actually tried this out. Also, I guess it would depend on where 
the hell you're trying to actually get to in the first place...

> Nowadays the route via the 
> right atrium, though the atrial septum, to the left atrium and from 
> there to the left ventricle is also often used.

Hmm, OK.

> BTW as you rightly guessed, that implies that the vast majority of 
> catheterizations go via the inferior vene cava. Entering via the 
> superior vene cava is very uncommon, except for the wires of a pacemaker 
> or ICD (I guess you ended up in webpages describing those procedures).

Actually, I just looked up the major blood vessels of the heart and 
tried to figure out which name goes with which tube on the diagram. 
(You'd think this would be easy... you'd be wrong.) I eventually 
determined that the two vena cavae are where the majority of blood 
enters from, and arbitrarily selected the superior one.

Firstly because "superior" sounds better [although in fact I gather it 
just means "higher up" in medical jargon], and partly because I imagined 
the route from the brain to the heart. Most people perceive their body 
looking down from where their head is. (Not that this has anything 
remotely to do with the surgical feasibility of inserting stuff from 
that direction...)

> In principle you can also enter via the right outflow tract and there 
> are also in general 4 lung venes (that transport oxygenated blood from 
> the lungs to the left atrium). Of the top of my head I don't know of any 
> procedure that uses any of those entry points.

Yeah, the heart is a double-pump, so there ought to be *two* entrances 
in theory. (There are apparently more because humans have two lungs, and 
because blood from above and below returns through different routes.)

On a completely unrelated note, apparently in some animals the heart is 
a single pump, and in yet others it's just a tube that sort of squirts, 
and there are no blood "vessels" at all. The internal organs just sit in 
a soup of... well, it's not even blood, it's haemolymph.

Then again, apparently some animals don't have red blood cells, the 
haemoglobin just floats in solution. Larger animals don't do that 
because to have enough haemoglobin to transport sufficient oxygen, their 
blood would be like treacle. So RBCs evolved which are packed with this 
oxygen-transport protein, but the blood remains liquid.

In other news, I spent a really absurd amount of time on Wikipedia. o_O

> To complete the picture you can also us a sternotomy or a laporoscopic 
> procedure, but don't try that at home.

Yeah, that or any other medical procedure even remotely involving your 
heart! o_O

Although I did hear about an off-duty medic who saved someone from a 
collapsed lung on an airoplane using a tube and a coathanger or 
something random like that...

Funny stuff, blood. Everybody seems to think it's red. Certainly if you 
spill it, everything within an 8-mile radius is coated scarlet and it 
looks like a chainsaw massacre has happened (when actually you merely 
got a paper cut)! But from what I've seen, blood is nearer black than 
red. I mean, if you get any real *quantity* of the stuff. It's very dark 
indeed.

Reminds me of the last time I had a nose bleed. Sure, it's only a small 
volume of blood. But it gets *everywhere*. And it feels really, really 
hot against your skin. Almost scalding hot. It really makes you feel 
like something very serious is happening - especially when it's dripping 
fast.

Somewhat unrelated, but... I remember my dad working on some plasma 
samples. He proffered a tube at me and said "well, you can definitely 
tell which volunteers had a good breakfast!" I swear, the amount of cow 
lard floating on the top of some of these samples was discusting! :-S

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

Post a reply to this message

On 6-7-2010 23:12, Orchid XP v8 wrote:
>>> At least I didn't say it was through the aorta. (That, of course, 
>>> would be the way *from* the heart, not *to* it.) I bothered to get 
>>> that much right. ;-)
>>
>> yes and no ;) Blood exits the heart via the aorta, but it used to be 
>> the standard entry point for catheters if you wanted to go to the left 
>> ventricle (where many arrhythmias originate).
> 
> Heh. I don't know if it's a rule of the Internet, but it probably should 
> be: For any conceivable topic, somebody else will know way, way more 
> about it than you. :-}

except that in this case you knew I would be such a somebody.

> 
> I would have thought trying to enter against the flow of blood through 
> the single largest blood vessel in the entire human body would be quite 
> difficult 

As you point out, it is big. Catheters are thin.

> - then again, I'm sure many people far more knowledgeable than 
> me have actually tried this out. Also, I guess it would depend on where 
> the hell you're trying to actually get to in the first place...
> 

>> BTW as you rightly guessed, that implies that the vast majority of 
>> catheterizations go via the inferior vene cava. Entering via the 
>> superior vene cava is very uncommon, except for the wires of a 
>> pacemaker or ICD (I guess you ended up in webpages describing those 
>> procedures).
> 
> Actually, I just looked up the major blood vessels of the heart and 
> tried to figure out which name goes with which tube on the diagram. 
> (You'd think this would be easy... you'd be wrong.) I eventually 
> determined that the two vena cavae are where the majority of blood 
> enters from, and arbitrarily selected the superior one.
> 
> Firstly because "superior" sounds better [although in fact I gather it 
> just means "higher up" in medical jargon], and partly because I imagined 
> the route from the brain to the heart. Most people perceive their body 
> looking down from where their head is. (Not that this has anything 
> remotely to do with the surgical feasibility of inserting stuff from 
> that direction...)

IIRC the first catheter insertion was via the arm, so that would have 
been the superior side. Aside, I think that you as a programmer would be 
more careful in selecting an apparently arbitrary choice of two. 
Especially if you know they are not interchangeable. Why didn't you go 
for e.g. the vena cava without mentioning wither inf. or sup.?

>> In principle you can also enter via the right outflow tract and there 
>> are also in general 4 lung venes (that transport oxygenated blood from 
>> the lungs to the left atrium). Of the top of my head I don't know of 
>> any procedure that uses any of those entry points.
> 
> Yeah, the heart is a double-pump, so there ought to be *two* entrances 
> in theory. (There are apparently more because humans have two lungs, 

with in most cases two venes entering from each lung (indeed an inferior 
and a superior).

> and because blood from above and below returns through different 
> routes.)
> 
> On a completely unrelated note, apparently in some animals the heart is 
> a single pump, and in yet others it's just a tube that sort of squirts,

In humans (and mammals and birds and probably also the reptiles and 
fishes) it starts out as a tube with peristaltic contractions only later 
the two separate circulations are formed. E.g. crocodiles have a single 
chamber, but don't make the assumption that therefore their heart is 
more primitive. For them that functions better than any 4 chambered 
heart would do.

Pity that given your interest in this topic (and in e.g. MathML) that 
you seem to be stuck in MK.

> and there are no blood "vessels" at all. The internal organs just sit in 
> a soup of... well, it's not even blood, it's haemolymph.
> 
> Then again, apparently some animals don't have red blood cells, the 
> haemoglobin just floats in solution. Larger animals don't do that 
> because to have enough haemoglobin to transport sufficient oxygen, their 
> blood would be like treacle. So RBCs evolved which are packed with this 
> oxygen-transport protein, but the blood remains liquid.
> 
> In other news, I spent a really absurd amount of time on Wikipedia. o_O

I think we noticed, and on WA.

>> To complete the picture you can also us a sternotomy or a laporoscopic 
>> procedure, but don't try that at home.
> 
> Yeah, that or any other medical procedure even remotely involving your 
> heart! o_O

I am not sure that sternotomy is 'remotely' involving hearts. I have 
been present at quite a number of procedures where this was the approach 
to open the heart and treat the inside.

Post a reply to this message

>> Heh. I don't know if it's a rule of the Internet, but it probably 
>> should be: For any conceivable topic, somebody else will know way, way 
>> more about it than you. :-}
> 
> except that in this case you knew I would be such a somebody.

Well, perhaps. But if I posted something about, say, iambic pentamiter, 
somebody here would probably turn out to be an expert on the subject.

> IIRC the first catheter insertion was via the arm, so that would have 
> been the superior side. Aside, I think that you as a programmer would be 
> more careful in selecting an apparently arbitrary choice of two. 
> Especially if you know they are not interchangeable. Why didn't you go 
> for e.g. the vena cava without mentioning wither inf. or sup.?

Well, I was going for comic effect rather than technical accuracy. A 
long technical term sounds more impressive.

>> Yeah, the heart is a double-pump, so there ought to be *two* entrances 
>> in theory. (There are apparently more because humans have two lungs, 
> 
> with in most cases two venes entering from each lung (indeed an inferior 
> and a superior).

OK, I didn't read that far.

>> On a completely unrelated note, apparently in some animals the heart 
>> is a single pump, and in yet others it's just a tube that sort of 
>> squirts,
> 
> In humans (and mammals and birds and probably also the reptiles and 
> fishes) it starts out as a tube with peristaltic contractions only later 
> the two separate circulations are formed. E.g. crocodiles have a single 
> chamber, but don't make the assumption that therefore their heart is 
> more primitive. For them that functions better than any 4 chambered 
> heart would do.

Well, the word "primitive" means "simpler", and it's sometimes taken to 
mean "less evolved". And people seem to think that simpler is worse, and 
more complex is better. Then agian, people think that worms are "less 
evolved" than humans - but they severely out-number us, so they can't be 
doing it that badly wrong...

> Pity that given your interest in this topic (and in e.g. MathML) that 
> you seem to be stuck in MK.

Heh. I'm "interested" in many, many topics. Fractals, data compression, 
encryption, statistics, artificial intelligence, digital signal 
processing, sound synthesis, logic design, biology, evolotion... the 
list goes on.

The GHC User Manual has a section "for over-interested souls". I think 
this is possibly the term that describes me...

>> In other news, I spent a really absurd amount of time on Wikipedia. o_O
> 
> I think we noticed, and on WA.

Ah WA... Very cool, but not especially useful. Like the data glove, it 
seems to be a solution in search of a problem.

Post a reply to this message

On 7/7/2010 3:17 AM, Invisible wrote:

> Heh. I'm "interested" in many, many topics. Fractals, data compression,
> encryption, statistics, artificial intelligence, digital signal
> processing, sound synthesis, logic design, biology, evolotion... the
> list goes on.
>
> The GHC User Manual has a section "for over-interested souls". I think
> this is possibly the term that describes me...

Yeah, describes me to a tee as well. Add chemistry and quantum physics 
on top of that.

>>> In other news, I spent a really absurd amount of time on Wikipedia. o_O
>>
>> I think we noticed, and on WA.
>
> Ah WA... Very cool, but not especially useful. Like the data glove, it
> seems to be a solution in search of a problem.

Indeed. Quite a fun toy, though.

-- 
~Mike

Post a reply to this message

>> Heh. I'm "interested" in many, many topics. Fractals, data compression,
>> encryption, statistics, artificial intelligence, digital signal
>> processing, sound synthesis, logic design, biology, evolotion... the
>> list goes on.
>>
>> The GHC User Manual has a section "for over-interested souls". I think
>> this is possibly the term that describes me...
> 
> Yeah, describes me to a tee as well. Add chemistry and quantum physics 
> on top of that.

Dude, this is povray.off-topic, the off-topic forum for users of a 
Turing-complete ray tracer that supports implicit surfaces and 
volumetric sampling of user-defined functions. I think "over-interested 
souls" probably covers the entire damned group! ;-)

And I could add chemistry, electronics, and a whole bunch of other stuff 
too. It's just that eventually you have to stop typing.

>> Ah WA... Very cool, but not especially useful. Like the data glove, it
>> seems to be a solution in search of a problem.
> 
> Indeed. Quite a fun toy, though.

For sure. Although it seems to be extremely good at utterly failing to 
comprehend what you mean.

Also, and this is the annoying part, WA is supposed to be this 
"revolutionary" system that will "make everything computable for 
anybody". The trouble is, it's powered by Mathematica, Wolfram's 

result, WA is deliberately crippled (i.e., it won't answer certain 
questions even though it could) in order to force you to buy Mathematica.

My personal feeling is that they should add a "pro" version for money 
that *does* solve every problem that the backend engine can handle. And 
then, instead of saying "WA doesn't know what to do with your input", it 
should actually *say* "you need the pro version to do that".

But anyway, flames aside...

Post a reply to this message

On 7-7-2010 10:17, Invisible wrote:

>>> On a completely unrelated note, apparently in some animals the heart 
>>> is a single pump, and in yet others it's just a tube that sort of 
>>> squirts,
>>
>> In humans (and mammals and birds and probably also the reptiles and 
>> fishes) it starts out as a tube with peristaltic contractions only 
>> later the two separate circulations are formed. E.g. crocodiles have a 
>> single chamber, but don't make the assumption that therefore their 
>> heart is more primitive. For them that functions better than any 4 
>> chambered heart would do.
> 
> Well, the word "primitive" means "simpler", and it's sometimes taken to 
> mean "less evolved". And people seem to think that simpler is worse, and 
> more complex is better. 

A crocodile heart may be more complex than a human heart, it is e.g. 
capable of adjusting the mixing of oxygenated and non-oxygenated blood 
according to how much is needed. That helps in keeping submerged for 
long times.

> Then again, people think that worms are "less 
> evolved" than humans - but they severely out-number us, so they can't be 
> doing it that badly wrong...

All animals alive today have evolved for exactly the same amount of 
time. If you count generations, smaller animals are in general more 
evolved than larger

>> Pity that given your interest in this topic (and in e.g. MathML) that 
>> you seem to be stuck in MK.
> 
> Heh. I'm "interested" in many, many topics. Fractals, data compression, 
> encryption, statistics, artificial intelligence, digital signal 
> processing, sound synthesis, logic design, biology, evolution... the 
> list goes on.

About 70% of these would have been useful in a job application here.

> The GHC User Manual has a section "for over-interested souls". I think 
> this is possibly the term that describes me...

I think that would also describe me, although I prefer to describe my 
interests as broad but not shallow.

>>> In other news, I spent a really absurd amount of time on Wikipedia. o_O
>>
>> I think we noticed, and on WA.
> 
> Ah WA... Very cool, but not especially useful. Like the data glove, it 
> seems to be a solution in search of a problem.

Or a set of answers in search of a search.

Post a reply to this message

>> Heh. I don't know if it's a rule of the Internet, but it probably 
>> should be: For any conceivable topic, somebody else will know way, way 
>> more about it than you. :-}
> 
> except that in this case you knew I would be such a somebody.

OK, well here's something you might know the answer to:

Does dancing around like a crazy thing for a few hours count as "a good 
cardio workout"?

(Obviously dancing something slow probably doesn't count. But something 
like my favourit dance, Rock & Roll, is really very energetic. At least, 
it is if you do it right...)

Post a reply to this message

On 8-7-2010 16:32, Invisible wrote:
>>> Heh. I don't know if it's a rule of the Internet, but it probably 
>>> should be: For any conceivable topic, somebody else will know way, 
>>> way more about it than you. :-}
>>
>> except that in this case you knew I would be such a somebody.
> 
> OK, well here's something you might know the answer to:

sorry

> Does dancing around like a crazy thing for a few hours count as "a good 
> cardio workout"?

I actually haven't a clue what a cardio workout is. Except that it a 
term used by people that work out in a gym. I am definitely not one of 
those.

Good dancing seems to be by using a lot of muscles, hence I would assume 
that it may be a usefull workout anyway. (Yet IANAD)

> (Obviously dancing something slow probably doesn't count. 

I wouldn't be too sure about that. Moving slow also involves alot of 
muscle tension. Google for tai chi (with current temperatures I am too 
lazy for even that).

> But something like my favourit dance, Rock & Roll, is really very 
> energetic. At least, it is if you do it right...)

Post a reply to this message

andrel wrote:
> I actually haven't a clue what a cardio workout is. 

It's aerobic exercise that gets your heart rate high and keeps it high. 
Usually meaningful only in contrast to an anaerobic which is like lifting 
weights to give your muscles strength.

So, dancing would be cardio unless you're *really* out of shape.

-- 
Darren New, San Diego CA, USA (PST)
    C# - a language whose greatest drawback
    is that its best implementation comes
    from a company that doesn't hate Microsoft.

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Darren New wrote:

> So, dancing would be cardio unless you're *really* out of shape.

Heh. What, like so fat that it's a physical feet to actually list that 
much flab out of the chair?

Actually, come to think of it... My mother has fat on her fat's fat, but 
one thing I have noticed is that her legs appear to be 100% solid muscle 
mass...

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