Every organ in the body needs blood. To provide this blood to all parts of the body, a network of tubes - arteries, veins and capillaries - stretch 60,000 miles in the average human body!
The heart is the major pump that pushes the blood out through the arteries to the capillaries, and itself requires blood to function and survive.
Blood pressure is important - for without it, blood would not reach the outer capillaries. If your blood pressure is to high, then things will literally explode - normally resulting in death. If your blood pressure is too low, then blood will not circulate efficiently - disease and death will be the end result.
Blood supplies all cells and tissue matter within the body with Oxygen. The Oxygen in the blood emanates from it's trip to and from the lungs, where it 'collects' Oxygen from the air we breathe.
Nutrients - so vital to all organs in the body - are transported by the blood in sometimes complex forms, to enable all body organs to continue to grow and function properly.
The Immune system also requires blood to be able to carry the vital white cells, with which it fights off various diseases and alien bodies that enter our own body.
What goes in. normally has to go out. Here again the blood is important - nay, Vital - for the elimination of waste products from our body.
Wounds are healed with the help of the coagulation abilities of the blood. Without its ability to coagulate, there would be continuous bleeding - resulting in wounds that will not heal or scar over - or even death.
Blood is also one of our internal 'mail' systems - carrying hormones to parts of the body where required. The hormones are often made/secreted in far off organs and need the transportation system supplied by the blood.
Blood also performs other relatively unknown functions, such as controlling body temperature - and also out body's pH levels.
So much for the internal importance of blood. But, reaching out to the extremes of it's 'highways' blood also contributes hugely to how our outward appearance presents itself to the world and those around us. The skin is very dependent upon a good supply of good blood. Forget the lotions - take care of your blood.