Pulmonary alveolus thin fluid coating within all alveoli. The fluid coating is produced by the body in order to facilitate the transfer of gases between blood and alveolar air. The surfactant is produced by the type II cells which are the most numerous cells in the alveoli, yet do not cover as much surface area as the squamous alveolar cells (a squamous epithelium). Type II cells also repair the endothelium of the alveolus when it becomes damaged. Insufficient surfactant in the alveoli can contribute to atelectasis (collapse of part or all of the lung). Without pulmonary surfactant, atelectasis is a certainty; however,
Body part as an object - the motor and visual cortices - involved in using or viewing objects and events, and thus facilitates the production of a representational gesture. Therefore, when objects are thought of using mental or visual imagery, more gestures should be produced. On the other hand, if an object is thought of only through its verbal representation, there should be fewer gestures present. Tool-use is the manipulation, or use, of an object using the hands. It is one of the many skills that separate humans from animals. There are two factors used to explain tool-use in humans. First of all, part of