Question

During exercise, sensory receptors detect changes in oxygen and carbon dioxide levels in the blood. This information is then sent to the brain's medulla, which causes the heart to beat faster and increases the rate of breathing. Exercising also causes the nervous system to signal the pancreas and thyroid gland to release hormones which regulate metabolism. Which statement is best demonstrated by this scenario? A. Hormones act as signal molecules between all body systems. B. Exercise is important for the body to function properly. C. Nerves transmit and respond to every major system in the body. D. Increased heart rate and blood flow decrease oxygen supply.

Answer 1

A. Hormones act as signal molecules between all body systems

Peripheral Chemoreceptors (Carotid + Aortic Bodies) and Central Chemoreceptors in the Medulla Oblongata detect high Carbon Dioxide levels in the blood during exercise. The respiratory centre in the Medulla Oblongata + PONS stimulate the intercostal muscles and the diphragm to contract in order to increase the rate and depth of breathing as to decrease levels of Carbon dioxide in the blood.

The thyroid gland secretes thyroxine which speeds up metabolism (the rate at which cells use glucose)

Answer 2

B. Nerves transmit and respond to every major system in the body.

Step-by-step explanation: