Via collateral circulation. This is an alternative route of blood circulation around the brain whenever one pathway is blocked or narrowed. The arterial arrangement of the brain are symmetrically designed in such a way that continuous blood flow the brain is ensured. The cerebral arteries (anterior and posterior) can be interchangeably shared if one of them is restricted. This means that if one artery is blocked/narrowed the other can accommodate the blood flow needed by the brain.
The correct answer to the question stated above is the first option: <span>an instinctive behavior was tied to a different stimulus. </span> Pavlov's experiment was a typical case of classical conditioning because an instinctive behavior was tied to a different stimulus.
TEMPERATURE: Although enzymes are also affected by the pH and the concentration of the enzyme and substrate in their environment, this specific example shows that enzymes are affected by temperature.
