Axis (anatomy)
In anatomy, the second cervical vertebra (C2) of the spine is named the axis (from Latin axis, "axle") or epistropheus.
It forms the pivot upon which the first cervical vertebra (the atlas), which carries the head, rotates.
The most distinctive characteristic of this bone is the strong odontoid process ("dens") which rises perpendicularly from the upper surface of the body. That peculiar feature gives to the vertebra a rarely used third name: vertebra dentata. In some judicial hangings the odontoid process may break and hit the medulla oblongata, causing death.
Read more about Axis (anatomy): The Body, Other Features, Additional Images
Famous quotes containing the word axis:
“He is the essence that inquires.
He is the axis of the star;
He is the sparkle of the spar;
He is the heart of every creature;
He is the meaning of each feature;
And his mind is the sky,
Than all it holds more deep, more high.”
—Ralph Waldo Emerson (1803–1882)