The primary cause for the development of shock following hemorrhage is: (A) Marked vasodilation, (B) Decreased blood volume, (C) Inadequate output by the hea, (D) Obstruction to blood flow
Answer is B. Hemorrhage is the most impoant cause of hypovolemic shock. There will be reduction in the venous return leading to a fall in cardiac output and BP. The severity of shock depends upon the rapidity of blood loss. Ref: Textbook of medical physiology by N Geetha, 3rd edition, page no. 204