PATHOLOGY

Detailed explanation-1: -Impaired oxygen supply (hypoxia) or reduced blood flow (ischemia) to the brain causes significant metabolic changes in neuronal and non-neural cells. It first leads to a rapid change in membrane lipid composition and enzyme activities and then to long-term changes in gene expression and levels of protein synthesis.

Detailed explanation-2: -Ischemia is insufficient blood flow to provide adequate oxygenation. This leads to tissue hypoxia (reduced oxygen) or anoxia (absence of oxygen). Ischemia results in hypoxia; however, hypoxia can occur with normal (or elevated) blood flow if, for example, the oxygen content of the arterial blood is decreased by anemia.

Detailed explanation-3: -Hypoxia is a state in which oxygen is not available in sufficient amounts at the tissue level to maintain adequate homeostasis; this can result from inadequate oxygen delivery to the tissues either due to low blood supply or low oxygen content in the blood (hypoxemia).