Blood Flow
The penumbra region typically occurs when blood flow drops below 20 mL/100 g/min. At this point electrical communication between neurons fails to exist.Cells in this region are alive but metabolic pumps are inhibited, oxidative metabolism is reduced but neurons may begin to depolarize again. Areas of the brain generally do not become infarcted until blood flow to the region drops below 10 to 12 mL/100 g/min. At this point, glutamate release becomes unregulated, ion pumps are inhibited and adenosine triphosphate (ATP) synthesis also stops which ultimately leads to the disruption of intracellular processes and neuronal death.
Read more about this topic: Penumbra (medicine)
Famous quotes related to blood flow:
“But even suppose blood should flow. Is there not a sort of blood shed when the conscience is wounded? Through this wound a man’s real manhood and immortality flow out, and he bleeds to an everlasting death. I see this blood flowing now.”
—Henry David Thoreau (1817–1862)
“The poet sings how the blood flows in his veins. He performs his functions, and is so well that he needs such stimulus to sing only as plants put forth leaves and blossoms.... His song is a vital function like breathing, and an integral result like weight.”
—Henry David Thoreau (1817–1862)