Bifalgorithm post

This is a vein. This is an artery. So what's the difference? A vein carries blood back to the heart from all parts of the body. An artery carries blood away from the heart to all parts of the body. This is a hormone. This is an enzyme. So what's the difference? A hormone is a chemical signal released by glands that controls body functions from a distance. An enzyme is a protein that speeds up chemical reactions happening inside the body. What confusing words should we do next?

This is a vein. This is an artery. So what's the difference? A vein carries blood back to the heart from all parts of the body. An artery carries blood away fr…