A mule is the result of a horse that has been bred with a donkey. Mules are generally sterile, meaning that they cannot be bred with each other in most cases. They also have 63 chromosomes. In appearance, mules may look very similar to donkeys. They also have stiff hair. Much like donkeys, mules are strong animals and tend to have calmer personalities.
To research the causes of Air embolism, consider researching the causes of these these diseases that may be similar, or associated with Air embolism: 1  Dyspnea. 2  Pulmaonary barotrauma. 3  Decompression syndrome. 4  Stroke. Thrombosis.
Causes of Emphysema. The most common emphysema causes are from breathing in fumes and other irritants that damage the lungs and airways. Cigarette smoking is the most common irritant that causes the disease, but other factors (including dust and genetics) can cause it as well.