Atelectasis from the outside (tumor, lymph node, tubercle). Another cause is poor surfactant spreading during inspiration, causing the surface tension to be at its highest which tends to collapse smaller alveoli. Atelectasis may also occur during suction, as along with sputum, air is withdrawn from the lungs. There are several types of atelectasis according to their underlying mechanisms or the distribution of alveolar collapse; resorption, compression, microatelectasis and contraction atelectasis. Relaxation atelectasis (also called passive atelectasis) is when a pleural effusion or a pneumothorax disrupts the contact between the parietal and visceral pleurae. Risk factors associated with increased likelihood of the
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