Whilst bushwalking a friend was giving me lots of advice including that I should elevate my feet during recovery so the blood could come back to the heart. This sounded very suspect to me. She said that your heart pumps blood out into the arteries and capillaries and then into the cells. Then another set of capillaries and veins (whatever) bring the blood back to the heart.
I googled it and as far as I could work out when the blood gets into the capillaries it joins up with the return capillaries and then the veins, but those return ones have these valve thingys which stop the blood going back downhill (so to speak).
So it seems that the whole circuit is really the heart pumping and creating the pressure to do the whole loop.
Can anyone tell me what is getting the blood back to the heart?
I could ask my friend who is a real doctor, but they just love to get asked medical questions in their time off 
Cheers
DrDoobie
That’s basically it. The original pressure from the heart’s contraction is sufficient to pump blood all the way around.
That being said, return of blood to the heart from “the periphery” is augmented by movement of (i.e. compression by) the leg muscles in particular. Of course, your friend is correct in pointing out that elevating your legs will also facilitate the return of blood (by gravity alone).
Sometimes when people have a tendency to low blood pressure, one of the things we advise is for them to wear rather tight full length stockings (support hose). These act to place a constant and relatively high pressure on the leg veins, thereby facilitating the flow of blood back to the heart. Having more blood in the heart causes the heart to contract more vigoursly which, in turn, increases the blood pressure (for those familiar with such things, this is termed "increasing the pre-load).
The circulatory system is closed. The heart pumps blood out of the left ventrical to the aorta, through the network of arteries, arterioles and capillaries. Those same capillaries become venules, then veins, all of which empty into the superior and inferior vena cavae, then into the right atrium and starts the process over again. At the capillary level, oxygen is exchanges for carbon dioxide from the ajoining cells.
The link gives a more detailed discription.
Thanks everyone! Good to know I was right (sort of)
And I’ll stay away from cats … another good suggestion!