Penumbra (medicine) | 合法醫療器材資訊網

Inpathologyandanatomythepenumbraistheareasurroundinganischemiceventsuchasthromboticorembolicstroke.Immediatelyfollowingtheevent,blood ...

Partially affected area surrounding an ischamic event

In pathology and anatomy the penumbra is the area surrounding an ischemic event such as thrombotic or embolic stroke. Immediately following the event, blood flow and therefore oxygen transport is reduced locally, leading to hypoxia of the cells near the location of the original insult. This can lead to hypoxic cell death (infarction) and amplify the original damage from the ischemia; however, the penumbra area may remain viable for several hours after an ischemic event due to the collateral arteries that supply the penumbral zone.

As time elapses after the onset of stroke, the extent of the penumbra tends to decrease;[1] therefore, in the emergency department a major concern is to protect the penumbra by increasing oxygen transport and delivery to cells in the danger zone, thereby limiting cell death. The existence of a penum...