Why are there so many capillaries in your bodies?

Answer 1

This is really a Biology question.

The general gist of it is that every cell in your body needs nutrients and oxygen, and give off waste products and carbon dioxide. Imagine making a flat sheet of cells (pack them in real tight for efficiency). The area of that sheet would be an estimate for the number of square miles of capillaries needed to feed them all.

Another way of estimating is think of slicing your body into sheets that are as thick as one cell, see how many sheets that would be, and multiplying by the area of that cross-section. This would be a rough estimate (very very rough) but it might be fun.

Answer 2

There are so many capillaries in our bodies so the blood can circulate fully around the body. The blood carries oxygen to our cells, and the capillaries carry around the blood to the hard to reach places, such as the tips of our fingers and the tips of our toes. When you cut of the circulation, or the blood flow, in your finger, and you get a bruise, this is because the capillaries have broken open. Without the capillaries, our cells would die from no circulation. Capillaries are very important for the Healthiness of our bodies.