Question

1. A person having exercised for a long time in a hot climate shows the following physiological features: the baroreceptors would ________ firing, leading to ________ secretion of ________ and thus ________ renal reabsorption of ________.

   		increase; increased; renin; increased; Na+
   		decrease; increased; renin; decreased; Na+
   		decrease; increased; vasopressin; increased; water
   		increase; decreased; vasopressin; decreased; water
   		decrease; decreased; vasopressin; increased; water

Answer 1

During exercise ,High utilization of ATP takes place and heat is also released by body tissues.which causes increase in body temperature.to maintain the temperature homeostasis ,Sweating takes place to reduce the body temperature to normal range.due to which body water content and electrolyte loss occur,and Plasma volume will decrease ,and there will be fall in blood pressure .Baroreceptor would be stimulated by change in pressure in Blood pressure ,leading to increased secretion of renin from the JG cells .Renin activates the Renin-Angiotensin -Aldosterone-system .Aldosterone increases the reabsorption of Na+ ions from the filtrate, and water reabsorption also takes place to achieve the blood pressure in normal range

Thus A is correct .