The West is blinking in disbelief â Vladimir Putin just invaded Ukraine. German diplomats, French Eurocrats and American pundits are all stunned.
The  circulatory system is the body's transport system. It is made up of a group of organs that transport blood throughout the body. The heart pumps the blood and the arteries and veins transport it. Oxygen-rich blood leaves the left side of the heart and enters the biggest artery, called the aorta.
Figure 26-1 shows the major organs of the digestive system. Table 26-1 summarizes the structures making up the digestive system. The main function of the overall digestive system (Box 26-1) is to break down food into simpler forms that the circulatory vessels can carry and pass through the cell membranes to the cells. The cells then use these food molecules or nutrients for energy and to build, maintain, and repair body tissues.