A question! (Biology and Medicine)

[Pumpkin Seeds]

Correct on both.  Unfortunately I couldn't figure out how to ask the neat part about the second question, so I'll just say cause I think it's neat.  Cardon Dioxide is often packaged in the form of acid.  So when there is an abundance of the substance in your body, such as with being unable to breath, your body goes into respiratory acidosis.  Obviously if you can't breath, your body cannot compensate for this.  Looking back over the case, I think the patient's pH level was near 7.1.  When pH goes below normal, proteins and hormones begin to slow.  Epinephrine is included in this affect.  So in this case, the epinephrine was floating around this patient's body but could not bind properly to its sites.  When the team intubated him and begin allowing the body to compensate, blowing off the CO2 and helping restore body pH to normal, the epinephrine could suddenly work.  So in an instant, you have a patient with near no pulse or pressure going through the roof and eventually dying.  I believe the heartrate was in the 280s and the pressure was like...240/180 or something ridiculous like that. 


As for aging, I used to know this one.  There is something in the cell that slowly winds down each time the cell begins to reproduce.  I forget the name, but basically as it begins to shorten in length the cell loses his ability to reproduce itself.  Oddly enough cancer cells do not have this particular trait and are immortal if given the correct amount of nutrients.  I've heard of their being research into using that trait to reverse this aspect of aging.

[Vekseid]

Telomerase is the term you are thinking of.

Only a partial answer of a partial answer, though :-p  It is a big problem.

[Pumpkin Seeds]

Since the medical thread fell into some neglect, I felt a small need to give it a pulse.  So let's start with something morbid.  One of the injections given for the death penalty is potassium chloride.  Why does this stop the heart so effectively?

[Question Mark]

Potassium chloride, having such a high acidity, instantly throws off the pH balance in the bloodstream.  Since pH is used to goven nueronical impulses that control muscles, it throws the nervous system into an "unrecoverable state of shock".  Unrecoverable because once that potassium chloride hits the heart, the cardiac muscles sieze up from the unbalanced pH level.  Without the heart pumping, and the entire cardiac nervous system shut down (not to mention all the nerves that the potassium chloride encountered along the way), the brain is deprived of oxygen, as is the entire rest of the body, resulting in tissue necrosis.  After several minutes, the necrosis is irreversible, and the inmate is pronounced dead.

This happens so quickly because the potassium chloride is injected directly into the vein.  Within two pumps, the majority of that salt will be pumped directly into the heart.  The actual necrosis and dying part takes another two-to-three minutes.  But, for all intents and purposes, if that gets into your heart, you're dead meat.

[Pumpkin Seeds]

Been awhile I know and I'm sort of ressurecting here, but I love this subject.  I've been wanting to bring it back for awhile but was sorta traumatized after physiology.  Anyway, Question Mark has a well thought out answer but not quite there.  Indeed with an injection of potassium chloride the pH levels would decrease and while some may be due to potassium, most of it is due to respitory failure.  If pH levels were lessened to such an extent, we would see rapid and shallow breathing in the person.  Descriptions say the person looks like they simply went to sleep. 

There is indeed an imbalance with pH and pH does play a role in neurological impulses.  Its role is more biochemical though as reactions will not occur under certain pH conditions.  The imblance is more eletrical between sodium and potassium, which governs cell membrane potential.  The diffusion of sodium into the cell versus the diffusion of potassium into the cell establishes the membrane potential.  That gradient is vital for life and is closely regulated by the cell.  Too much sodium in and potassium out, the cell activates the sodium/potassium pump to correct.  This balance is very precarious and a great deal of ATP is invested by the cells in maintaining it.

The large injection of potassium into the bloodstream destroys that diffusion gradiet.  No membrance potential, no action potential generation, no heart contraction and death soon follows.  This can be seen on an EKG as the person goes into ventricular tachycardia with the QRS wave becomes wider and taller.  This displays a growing length of time in the heart's contractions as it cannot depolarize and repolarize as fast.

The pH explanation may be more applicable to a more chronic form of hyperalemia.

[Question Mark]

*medical terms makes my mind go fuzzy*

Nice explanation there.  After I looked up the bigger words, it made perfect sense.  :p

There is currently only one place on Earth's upper crust that is suspected of having absolutely no life what-so-ever.  Name it and give three reasons why some believe life cannot exist there.