Line 9: Line 9:  
*Caudal Cerebellar Arteries: supply the caudal and lateral aspects of the cerebellum.
 
*Caudal Cerebellar Arteries: supply the caudal and lateral aspects of the cerebellum.
 
The arrangement of the Circle of Willis means that if one part of the circle becomes blocked or narrowed (stenosed), or one of the arteries supplying the circle is stenosed, blood flow from the other blood vessels can continue to provide a continuous supply of blood to the brain.  
 
The arrangement of the Circle of Willis means that if one part of the circle becomes blocked or narrowed (stenosed), or one of the arteries supplying the circle is stenosed, blood flow from the other blood vessels can continue to provide a continuous supply of blood to the brain.  
 +
 +
===Blood Supply to the Circle of Willis===
 +
In order to provide details of the species differences regarding blood supply to the brain, it is necessary to highlight the main areas of anatomy that are important within and around the circle of Willis. The following informatino is very generalised and is used to provide knowledge and background to the species specifics given below.
 +
<br />
 +
<br />
 +
The main blood supply to the circle is via the paired internal carotid arteries and the basilar artery. The basilar artery receives blood from the ventral spinal artery and the vertebral artery (the vertebral artery is a branch of the subclavian artery running through the vertebral foramina of C1 - C6). The internal carotid artery receives blood supply from the external carotid artery, the common carotid artery and in some species also the vertebral artery. In some species
    
<br> <u>Note</u>: The basilar artery and middle cerebral arteries, though they supply the brain, are not considered part of the circle.  
 
<br> <u>Note</u>: The basilar artery and middle cerebral arteries, though they supply the brain, are not considered part of the circle.  
6,273

edits