A runner's heartbeat increases before the race starts. This is mostly related to the effect of which hormone?
Answer and explanation
Correct answer: Adrenaline
Before a race, excitement and anticipation activate the sympathetic stress response. The adrenal glands release adrenaline, which increases heart rate and breathing and directs more blood toward skeletal muscles. These changes prepare the body for rapid action. Insulin regulates blood glucose, while auxin and cytokinin are plant hormones, so they do not explain the runner’s immediate heartbeat increase. Therefore B is correct.
Frequently asked questions
What is the correct answer to this question?
Adrenaline
Why is this the correct answer?
Before a race, excitement and anticipation activate the sympathetic stress response. The adrenal glands release adrenaline, which increases heart rate and breathing and directs more blood toward skeletal muscles. These changes prepare the body for rapid action. Insulin regulates blood glucose, while auxin and cytokinin are plant hormones, so they do not explain the runner’s immediate heartbeat increase. Therefore B is correct.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: World of Living. Topic: Control and Coordination.
