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.
The brain is one of the largest and most important organs of the human body. It sends messages to and receives messages from all over the body. The brain is one of the largest and most important organs of the human body. Weighing in at about three pounds, this organ is covered by a three layered protective membrane called the meninges. The brain has a wide range of responsibilities. From coordinating our movement to managing our emotions, this organ does it all. The brain is composed of three main divisions: the forebrain, brainstem, and hindbrain. Forebrain. The forebrain is the most complex of the three parts.