Increasing adrenalin content of the blood would be expected to decrease the flow of blood to the

Analyzing the question

Adrenaline (epinephrine) is the "fight or flight" hormone released by the adrenal medulla. The question asks which organ would receive less blood when adrenaline rises.

The concept

Adrenaline prepares the body for emergency action. It:

• Increases heart rate and force of contraction, so the heart gets more blood.
• Dilates the bronchioles and increases blood flow to the lungs for more oxygen uptake.
• Dilates blood vessels in skeletal muscles, and the brain keeps or increases its supply to stay alert.
• Releases glucose from the liver (glycogen converted to glucose).
• Constricts blood vessels (vasoconstriction) in the skin, kidneys, and digestive organs (gut), which are not needed in an emergency.

Working through the options

• A. Liver: The liver is part of the digestive/splanchnic circulation. Blood is diverted away from the digestive system (gut and its associated organs) towards muscles, so the flow to this region decreases. This is the best answer among the options, although the liver itself is also stimulated to release glucose.
• B. Heart: Blood flow increases, because the heart works harder and the coronary vessels dilate.
• C. Lungs: Flow increases to support greater gas exchange.
• D. Brain: Flow is maintained or increased, because the brain must stay alert.

Answer

By elimination, the heart, lungs, and brain all keep or increase their blood supply, while the organs of the digestive region (including the liver) get reduced flow. The correct option is **A.

Tip: Remember "fight or flight" means blood goes to the heart, lungs, brain, and muscles, and away from the gut, skin, kidneys, and digestive organs. In elimination questions, find the organs that are essential for emergency action and remove them first.