informal leader. An individual within an organization that is viewed as someone worth listening to due to their perceived experience and reputation among peers. The informal leader does not hold any position of formal authority or power over the peers choosing to follow their lead but can influence the decisions of others.
The mediastinum (from Medieval Latin mediastinus, midway) is the central compartment of the thoracic cavity surrounded by loose connective tissue, as an undelineated region that contains a group of structures within the thorax.he mediastinum lies within the thorax and is enclosed on the right and left by pleurae. It is surrounded by the chest wall in front, the lungs to the sides and the spine at the back. It extends from the sternum in front to the vertebral column behind, and contains all the organs of the thorax except the lungs.
The heart is in the thoracic cavity in a part called the mediastinum. It is protected by the pericardium, a membranous sac that surround the heart. The mediastinum is that spa â¦ ce in the thoracic cavity between the lungs that contains the heart.It also contains the aorta, esophagus, trachea and thymus. The pleural cavity is the space in the chest between the lungs.he area present between two lungs in chest cavity is called mediastenum.this is the place where heart is present.The mediastinum lies between the right and left pleurae pleurÃ¦ in â¦ an d near the median sagittal plane of the. chest