1 Go to the Tools menu and select Export. 2  Name the file. 3  Examples might be: AddressBook-Thunderbird or ListName-Thunderbird and choose to save it to your Desktop. 4  Change the format to: Comma Separated. 5  Click the Save button. 6  Log into gmail.rider.edu and navigate to Contacts. Go to the Tools menu and select Export. 2  Name the file. 3  Examples might be: AddressBook-Thunderbird or ListName-Thunderbird and choose to save it to your Desktop. 4  Change the format to: Comma Separated. 5  Click the Save button. 6  Log into gmail.rider.edu and navigate to Contacts.
Full Answer. In addition to two upper chambers, the heart also has two lower chambers. The lower chambers are known as the left and right ventricles, which have a primary responsibility of pumping blood out of the heart. Separating the upper and lower chambers are different valves, which control the direction and rate of blood flow. A complete circulating cycle is defined as each instance the two atria bring in blood and the ventricles pump out blood.
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.