Mini excavators comprise the smallest models available. This category includes: micro excavators that weigh as little as 800 kg or less; mini excavators that average around 3,000 kg; and midi versions that may be upwards of 6 tonnes. Mini excavators are perfect for construction jobs in small spaces and other lighter work.
The inner layer of the pericardium is attached to the heart muscle. A coating of fluid separates the two layers of membrane, letting the heart move as it beats. Your heart has 4 chambers. The upper chambers are called the left and right atria, and the lower chambers are called the left and right ventricles. A wall of muscle called the septum separates the left and right atria and the left and right ventricles.
Rating Newest Oldest. 1  Technically the atria and ventricles are separated by a structure known as the Cardiac Skeleton (also known as the Fibrous Skeleton of the Heart). This is constructed of collagen and connective tissue and forms what is known as the base of the heart. 2  Left side the mitral (Bicuspid valve) separates the ventricle and atrium.