Circle of Willis

The circle of Willis is a circle of blood arteries supplying the brain. It is formed by both the internal carotid arteries and the basilar artery.

After the internal carotid arteries enter the skull from each side, they will each trifurcate into the anterior cerebral artery, middle cerebral artery, and posterior communicating artery.

The vertebral arteries, entering the skull posteriorly, will join to form the basilar artery. The basilar artery bifurcates into the right and left posterior cerebral arteries.

The two anterior cerebral arteries from both sides are joined together anteriorly by the anterior communicating artery. The posterior commicating arteries join the posterior cerebral arteries, completing the circle of Willis.

As the arteries in the circle of Willis form a complete ring, they effectively act as anastomoses for each other. This means that if any one of the communicating arteries becomes blocked, blood can flow from another part of the circle to ensure that blood flow is not compromised.



In the News

World Culinary Institute: Visit With the Masters
Brief biographies of four famous chefs: Fernand Point, Auguste Escoffier, Julia Child, and James Beard. Includes descriptions of culinary careers and highlights, such as Escoffier's "revolutionizing and modernizing the menu, the art of cooking and the organization of the professional kitchen,"and how Beard "appeared in his own segment on television's first cooking show on NBC in 1946."From the World Culinary Institute, a site that links to hundreds of cooking schools and related sites.

San Andreas Earthquake Observatory Achieves Milestone As Drillers Pene
The San Andreas Fault Observatory at Depth (SAFOD) reached a significant goal on Aug. 2 when scientists drilled into a seismically active section of the fault approximately two miles below the surface of the Earth.

Exercise Combats Metabolic Syndrome In Older Adults
Researchers at Johns Hopkins have determined that in people age 55 to 75, a moderate program of physical exercise can significantly offset the potentially deadly mix of risk factors for heart disease and diabetes known as the metabolic syndrome.

UC Retains Los Alamos Contract
The laboratory that built the atomic bomb will continue to be managed by the University of California, continuing a relationship that goes back to the establishment of Los Alamos in 1943.  

Possible Key To Autoimmune Disease
A self DNA-peptide complex triggers an immune response like that caused by a virus or other invading microbe. Researchers believe this response is both a likely key driver of autoimmune disease and an integral part of an early warning system that flags tissue damage to launch a protective inflammatory response to injury.

First Evidence Of Stem Cells In Pancreatic Tumors
University of Michigan Comprehensive Cancer Center researchers have discovered the small number of cells in pancreatic cancer that are capable of fueling the tumor's growth. The finding is the first identification of cancer stem cells in pancreatic tumors.

Small Furry Mammal Was Capable Of Gliding Flight Possibly Before Birds
An American Museum of Natural History paleontologist and his colleagues have named a new order of mammals based on their description of a fossil of a bat- or squirrel-sized Mesozoic mammal, called Volaticotherium antiquus (meaning "ancient gliding beast"), which was capable of gliding flight. The rock beds that yielded the fossil date to at least 125 million years ago, so the new fossil extends the earliest record for gliding flight in mammals by 70 million years or more and indicates that mammals experimented with gliding flight and aerial life at about the same time that birds first took to the skies, possibly even earlier.

Love, Internet Style
"Less Than Three" is a dangerously cute animated video to a lethally cute song about online relationships. In Table of Malcontents.

How 'Memory'T Cells Curb The Spread Of Viruses Throughout The Body
A scientific discovery helps explain how "memory"T cells protect the body from viral diseases. The research shows lymph nodes are not just organs where immune cells reside and proliferate, but also are the sites where a major fight against the spread of an invading virus occurs.

Chronic Back Pain Shrinks 'Thinking Parts' Of The Brain, Study Finds
Chronic back pain, a condition afflicting many Americans, shrinks the brain by as much as 11 percent -- equivalent to the amount of gray matter lost in 10 to 20 years of normal aging, a Northwestern University research study found.


MP3 Music Downloads

Preview songs, Download Free Music,Burn CDs at ITunes.com
iTunes_RGB_9mm

 


Google




InformationQuickFind.com - Find Information Fast

Links