Submit. Â· just now. Report Abuse. when a rock is subjected to severe heat, then dramatic cooling onion weathering takes place. This is a form of physical weathering. The sudden change of temperature weakens the outer layer of rock and it will crumble away, this happens to rocks in the desert.
Definition. Common arterial trunk (CAT) is characterized by a single arterial trunk that arises from the base of the heart and gives origin to the systemic, coronary and pulmonary circulation. A large ventricular septal defect (VSD) is almost always present.
The pulmonary trunk is a major vessel of the human heart that originates from the right ventricle. It branches into the right and left pulmonary arteries , which lead to the lungs. Each of these vessels has elastic walls similar to those of the aorta, though somewhat thinner, and they