epistropheus

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ax·is (ax),

, pl.

ax·es

(ak'sis, ak'sēz), Do not confuse this word with access.
1. A straight line joining two opposing poles of a spheric body, about which the body may revolve.
2. The central line of the body or any of its parts.
3. The second cervical vertebra.
5. The central nervous system.
6. An artery that divides, immediately on its origin, into a number of branches, for example, celiac axis.
[L. axle, axis]

epistropheus

/epi·stro·phe·us/ (-stro´fe-us) axis; see Table of Bones.

epistropheus

See axis.

axis

Anatomy 
The second bone of the vertebrae (C2), which contains a distinct bony protuberance, the odontoid process (dens), on which the first cervical vertebra (C1, the atlas), which carries the head, rotates.

Significance, execution
During judicial hangings, the odontoid process typically breaks off and is forced into the medulla oblongata, which contains the cardiac, respiratory and vasomotor centres that control involuntary functions (e.g., breathing, heart rate and blood pressure), usually resulting in instant death.

Medpspeak
(1) A central or straight line between two structures.
(2) A functional centre between two or more physiologically related activities—e.g., brain-gut axis, hypothalamic-pituitary-adrenal axis.

ax·is

, pl. axes (ak'sis, ak'sēz)
1. A straight line joining two opposing poles of a spheric body, about which the body may revolve.
2. The central line of the body or any of its parts.
3. The vertebral column.
4. The central nervous system.
5. The second cervical vertebra.
Synonym(s): epistropheus, vertebra C2, vertebra dentata.
6. An artery that divides, immediately on its origin, into a number of branches, e.g., celiac axis.
See: trunk

epistropheus

see axis (2).