Relative to the local standard of rest, our Sun and the Earth are moving at about 43,000 miles per hour (70,000 km/hr) roughly in the direction of the bright star Vega in the constellation of Lyra. This speed is not unusual for the stars around us and is our milling around speed in our suburban part of the Galaxy.
Anatomy of the Heart Definitions. The heart is the size of your fist and it is located on the left side of your. chest. The heart is divided into four chambers. Right Atrium. The right atrium receives de-oxygenated blood from the body through the. superior vena cava (head and upper body) and inferior vena cava (legs and. lower torso).
The heart is made of a special kind of muscle called myocardium, and is enclosed in a double-layered, membranous sac called a pericardium. The heart lies in the chest cavity between the lungs. It is composed of four chambers, many large arteries and many veins. The four chambers are called atrium and ventricles. A wall of muscle divides the heart into two cavities: the left cavity pumps blood throughout the body, while the right cavity pumps blood only through the lungs. Two chambers of the heart lie in the left cavity and two chambers lie in the right cavity.