"The sky calls to us. If we do not destroy ourselves, we will one day venture to the stars."
I made these to fit the Facebook cover photo size - feel free to use them with the post’s link. Photo courtesy: ESA/NASA.
The circulatory system is an organ system that permits blood and lymph circulation to transport nutrients (such as amino acids and electrolytes), oxygen, carbon dioxide, hormones, blood cells, etc. to and from cells in the body to nourish it and help to fight diseases, stabilize body temperature and pH, and to maintain homeostasis.