circle of Willis

موضوع: circle of Willis الإثنين يونيو 02, 2008 9:12 am

The circle of Willis (also called the cerebral arterial circle or arterial circle of Willis) is a circle of arteries that supply blood to the brain. It is named after Thomas Willis

Components:

Anterior cerebral artery (left and right)
Anterior communicating artery
Internal carotid artery (left and right)
Posterior cerebral artery (left and right)
Posterior communicating artery (left and right)

The basilar artery</A> and [url=http://en.wikipedia.org/wiki/Middle_cerebral_arteries]middle cerebral arteries, though they supply the brain, are not considered part of the circle

Anatomic variation
Considerable anatomic variation exists in the circle of Willis. Based on a study of 1413 brains, the "textbook version" of the circle is only seen in 34.5% of cases. In one common variation the proximal part of the posterior cerebral artery is narrow and its ipsilateral posterior communicating artery is large, so the internal carotid artery supplies the posterior cerebrum. In another variation the anterior communicating artery is a large vessel, such that a single internal carotid supplies both anterior cerebral arteries.

موضوع: رد: circle of Willis الإثنين يونيو 02, 2008 2:51 pm

thank you for your good subject

موضوع: رد: circle of Willis الإثنين يونيو 02, 2008 5:16 pm

لك الشكر دكتورنا
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