. physiology chapter 14 In what ways is the heart unlike most human-built pumps? Why do we need a circulatory system anyway? What structures ensure unidirectional flow?

There are unique and more complex form of organs which are required to construct the multi-cellular and more complex form of life i.e Human beings. As, human body has a circulatory system for blood circulation and transportation of minerals and water to the different cells and tissues inside the human body.

Explanation:

While, the medium for transportation can be termed as water,H₂O. And the blood plasma along with the different blood cells composes the total mass of the human blood, as the combine to form the actual mass of the human blood. There is human heart with right ventricle and right auricle for receiving of the de-oxygenated blood from all over the body and pumping it towards the lungs for removing the carbon dioxide,CO₂ from it. While, the left side of the heart consists of the oxygenated form of blood received by the blood via the left auricle.As, there are different pathways through which the circulation of blood medium takes place, as there are arteries, veins and capillaries for the movement of the required material to and fro from the different points or cells inside the human body in a more specific mechanism.The veins are there to ensure the blood is transported from the different origins or points inside the body back towards the human heart. As there are certain specification of veins that makes it able to have the maximum amount of de-oxygenated blood inside it ( As it has the values or the structures which inhibits the back flow of de-oxygenated blood to the tissue from which it was collected).

Icannot see any engraving so i cant answer 12.massacre means wholesale slaughter and thats what happend when they the boston citizens