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 carries deoxygenated blood from the heart to the right and left pulmonary aa.; each pulmonary a. carries deoxygenated blood to the hilum of one lung; bronchial aa. supply oxygenated blood to the tissues of the lung as far distally in the bronchial tree as the respiratory bronchioles.