Question

An athlete is running a marathon on a hot, dry day Which of the following physiological responses would be most likely to occur in the athlete's body by the end of the race?

• A. The athlete would produce dilute urine.
• B. The athlete would have decreased blood osmolarity.
• C. The athlete would have increased levels of antidiuretic hormone.
• D. The athlete would secrete less epinephrine.
• E. The athlete would have an increase in the amount of urine produced.

Answer 1

The correct option is C The athlete would have increased levels of antidiuretic hormone.

The athlete may suffer from dehydration (a condition in which there is excessive water loss from the body fluids) due to running a marathon on hot dry day. Due to this, ADH or antidiuretic hormone will be secreted from the neurohypophysis of pituitary gland. The release of this hormone is normally seen when osmoreceptors in hypothalamus detect an increase in osmolarity of blood. In this situation, osmoreceptor cells also promote thirst. It also increases the reabsorption of water in distal convulated tubule and collecting duct.

So, the correct answer is 'The athlete would have increased levels of antidiuretic hormone'.