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 language of dogs emotions, or communicating intentions. Understanding the body language of dogs can also aid in optimal obedience training, as observation of body language may reveal when the dog is most motivated and therefore provides a time-frame whereby dogs will learn more readily. In general, accurately assessing the body language of dogs is quite beneficial as it allows humans to react appropriately to emotions and intentions of the dog. Thus, it fosters successful companionship between the dog owner and pet. Alternatively, ignoring the body language of dogs can pose as a threat for not only humans, but for dogs too. Properly assessing