Blood

[barry1010]

Question from granddaughter this morning. I have no clue.
Blood is pumped by the heart around the body. Does it always go down one arm and one side and always up the other?

[Sqad]

LOL.......Good question.
It goes down AND up each arm and the same in the legs.
Blood is pumped around the body through arteries and back to the heart in veins,

[emmie]

one for sqad this morning...

[woofgang]

no it goes down and up both legs and arms otherwise the "back to the heart" leg and arm muscles wouldn't get enough oxygen

[emmie]

there you are....

[bhg481]

Blood doesn't go round the body, as such; it goes from the heart to each limb and each organ via an artery and then comes back to the heart via a vein.

[woofgang]

I think your granddaughter may have seen a diagram of the circulatory system? many of them show the veins on one arm and leg and the arteries on the other and this could be misleading?

[emmie]

learn something new every day on AB.

[barry1010]

Thanks all :) I have a feeling she was was trying to catch me out - she's 8. I shall phone her and give her a very, very long explanation :D

[jackthehat]

I've always wondered what happens when a limb/lower-limb is amputated....especially in the past when knowledge of the blood system was rudimentary, at best.

The arterial blood has no way of 'getting back'....and yet amputees don't end up with all of their blood sitting at the end of an engorged stump.

[rowanwitch]

As far as I remember a new capillary net forms linking the bigger vessels. The biggest ones at the end close off and the branches further back form the new supply.

[barry1010]

Oooh - excellent point, Jack

[bhg481]

Blood enters a limb via an artery and finds its way to a vein via capilleries in muscles. If you chop a limb off you block the artery and vein at that point. It's like the lighting circuit in your house - there's a live feed and a neutral return with bulbs connected across it; the live is the artery, the neutral is the vein and the bulbs are the capilleries.

[Peter Pedant]

if the artery sort of goes south and the veins go back up twizzled around the artery
possible then this is a counter current

of which there is one in the kidney, and also limbs

it explains why ducks feet dont fall off when they swim in cold water. and why swans dont keel over ffrom cold on a cold day