How does our body respond when adrenaline is secreted into the blood?
When adrenaline is secreted into the blood, it acts on target organs like the heart. As a result, the heart beats faster, leading to an increased supply of oxygen to the muscles.
The blood supply to the digestive system and skin is reduced due to the contraction of muscles around small arteries. This effectively diverts blood to our skeletal muscles.
Additionally, the breathing rate increases because of contractions of the diaphragm and rib muscles. All these responses together enable the body to be ready to deal with the situation.
Explanation
The answer is derived directly from the textbook section describing the effects of adrenaline. It highlights the three main physiological changes: increased heart rate, diversion of blood from non-essential organs to skeletal muscles, and increased breathing rate. These changes prepare the body for 'fight or flight'.