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.
Air Embolism. An air embolism is an obstruction in a vein or artery caused by a bubble of gas. Air enters the circulatory system when the pressure gradient favors movement of air or gas from the environment into the blood. A venous air embolism is the most common form of air embolism.
An embolism is the lodging of an embolus, a blockage-causing piece of material, inside a blood vessel. The embolus may be a blood clot (thrombus), a fat globule, a bubble of air or other gas (gas embolism), or foreign material. An embolism can cause partial or total blockage of blood flow in the affected vessel. Such a blockage (a vascular occlusion) may affect a part of the body distant from where the embolus originated. An embolism in which the embolus is a piece of thrombus is called a thromboembolism.