countercurrent heat exchange
The horizontal arrows in the figure of countercurrent heat exchange show that the
arterial blood can bypass the legs as needed when temperatures are too low to function properly.
goose’s legs get progressively warmer as blood flows away from the abdomen, decreasing heat loss.
lack of insulation in the goose's legs increases the metabolic energy needed to warm the blood.
warmer arterial blood transfers heat to the cooler venous blood, reducing heat lost to environment.

Question

countercurrent heat exchange
The horizontal arrows in the figure of countercurrent heat exchange show that the  
arterial blood can bypass the legs as needed when temperatures are too low to function properly.
goose’s legs get progressively warmer as blood flows away from the abdomen, decreasing heat loss.
lack of insulation in the goose's legs increases the metabolic energy needed to warm the blood.
warmer arterial blood transfers heat to the cooler venous blood, reducing heat lost to environment.

anonymous · Answer

the figure just shows two up and down arrows down arrow for artery and down for veins in for a goose