h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

while having a conversation with a friend he stated that every cell in the human body must be connected to the blood supply

is this the case?


Taff
agent of kaos

Yes, a cell needs oxygen to respirate* otherwise it dies. Oxygen is provided by the blood.

Not all the blood supply is huge viens and arteries though. Cells are fed oxygen from blood by the tiny one-cell-thick capilliaries.





*Burn sugar to provide energy to live.

** normally spelled 'respire'



B

Many cells in the human body at least are too far away from capilliarys to take ozygen and nutrients directly from such blood vesels hence interstitial tissue fluid (lympth effectively) is squeezed out of the capiliarys once they enter the tissues, oxygen travels down the gradient into teh extracellular tissue fluid and this permiates deeper into the tissues along with nutrients etc that also pass out of the blood vessels by diffusion etc., and the cells of the tisues themselves too far from the capiliary to recieve oxygen/nutrients direct take these from the interstitial/tissue fluid, which then gets renamed lymph as it moves on and eventually enters the lymphatic system before it all gets dumped back into the circularory system, somewhere near the aorta or vena cava I forget which I think

the cell in our body could exsplode which gives enternal blood coming out everwere!

A cell exploding would only leak cell contents around the body, which doesn't include blood sadly.

Quite right B

I'd still count that as connected to the bloody supply 2legs.
How far away can a cell be from a capillary and stills survive?

Yeh, cells don't contain blood.... well, its not* the blood supply/circulatory system once its out of the vessels and into teh tissues, its then its tissue fluid, then once its in the lymphatics its lympth, and the lymphatic system isn't part of the circulatory/blood supply system as its not directly linked to it at 'both ' ends, and its kinda 'passive' in how the lympth moves up the lymph vessels, at least in comparason to the circulatory/blood system, though off course ultimately the heart does have some* affect on the lympatic system, as I guess* there must be some kinda 'sucking' force on the lymphatics as a result of where the lymph ultimately drains back into the circulatory/blood system...

Lymph vessels do contain valves to stop if flowing 'backwards' as I recall, in the same way that veins do. IIRC

EERRRR..... probably.... T'was a long time ago I looked at any of that stuff.... actually I seem to recall that too hang on... I should have my bluddy uni notes here on the PC

'while having a conversation with a friend he stated that every cell in the human body must be connected to the blood supply'

is this the case?

Yes, although not directly. The capillaries pass very close to each cell.

Amazing really, seeing as the body contains of the order of 100 trillion cells.