axis
Top
(ăk'sĭs) 
n., pl., ax·es (ăk'sēz').
n., pl., ax·es (ăk'sēz').
- A straight line about which a body or geometric object rotates or may be conceived to rotate.
- Mathematics.
- An unlimited line, half-line, or line segment serving to orient a space or a geometric object, especially a line about which the object is symmetric.
- A reference line from which distances or angles are measured in a coordinate system.
- A center line to which parts of a structure or body may be referred.
- An imaginary line to which elements of a work of art, such as a picture, are referred for measurement or symmetry.
- Anatomy.
- The second cervical vertebra on which the head turns.
- Any of various central structures, such as the spinal column, or standard abstract lines used as a positional referent.
- Botany. The main stem or central part about which organs or plant parts such as branches are arranged.
- One of three mutually perpendicular lines that define the orientation of an aircraft, with one being along its direction of travel and the other two being perpendicular to the direction of travel.
- A line through the optical center of a lens that is perpendicular to both its surfaces.
- One of three or four imaginary lines used to define the faces of a crystal and the position of its atoms.
- An alliance of powers, such as nations, to promote mutual interests and policies.
- Axis The alliance of Germany and Italy in 1936, later including Japan and other nations, that opposed the Allies in World War II.
[Middle English, from Latin.]
Top
A straight line indicating center of symmetry of a solid or plane figure.
1. The second cervical vertebra. It has a vertical superior process called the odontoid process, around which the atlas rotates.
2. See axis of rotation.
Axis
An imaginary straight line passing through the North Pole, the center of the Earth, and the South Pole. The Earth rotates around this axis.
Top
- The central stalk of a compound leaf or flower cluster; the main stem of a plant. For example, the trunk is the axis of a pine tree.
- An imaginary straight line that subdivides a garden, often marked by a walkway or path.
Word Tutor:
Top
axis
IN BRIEF: The straight line (real or imagined) on which something rotates.
I cannot believe that the inscrutable universe turns on an axis of suffering; surely the strange beauty of the world must somewhere rest on pure joy!
— Louise Bogan
Tutor's tip: "Ask" (request) permission before using an "ax"/"axe" (tool with a heavy head fixed to a handle) to cut firewood. You can use "axes" (tool for heavy chopping) to cut down trees. The earth spins on its "axis" (mathematical straight line).
LearnThatWord.com is a free vocabulary and spelling program where you only pay for results!
In geometry, a straight line about which an object may rotate or that divides an object into symmetrical halves.
Top
- a straight line about which a body or three-dimensional figure, e.g. a crystal, is considered to rotate.
- one of the reference lines of a co-ordinate system.
- the second vertebra of the neck in higher vertebrates.
| axin, axial ratio, axial | |
| axokinin, axon, axonal transport |
Top
Pl. axes [L., Gr.]
1. a line through a center of a body, or about which a structure revolves.
2. the second cervical vertebra.
- celiac a. — celiac trunk.
- a. cylinder — axon.
- dorsoventral a. — one passing from the back to the belly surface of the body.
- electrical a. of heart — the resultant of the electromotive forces within the heart at any instant. See also mean electrical axis.
- external bulbar a. — the optical axis that connects the anterior and posterior poles of the eyeball. Called also optic axis.
- frontal a. — an imaginary line running from right to left through the center of the eyeball.
- a. of heart. — a line passing through the center of the base of the heart and the apex.
- optic a. — see external bulbar axis (above).
- orbital a. — a line passing through the apex of the bony orbit and the center of the opening of the orbit.
- sagittal a. — an imaginary line extending through the anterior and posterior poles of the eye.
- visual a. — an imaginary line passing from the midpoint of the visual field to the fovea centralis.
Top
(ak′sis)
n
n
1. a straight line around which a body may rotate. n 2. the second cervical vertebra.
Random House Word Menu:
Top
categories related to 'axis'
- Maps and Cartography - axis: imaginary line through Earth’s center from North to South Pole around which Earth rotates
- Celestial Phenomena and Points - axis: imaginary line through center of body about which it rotates
- Quantities, Relationships, and Operations - axis: straight line for reference in graph, such as Cartesian coordinate; straight line through center of plane or solid around which it is symmetrically arranged
- Dimensions and Directions - axis: straight line about which a body rotates or around which parts of body are symmetrical
See crossword solutions for the clue Wikipedia on Answers.com:
Top
Axis (anatomy)
| Bone: Axis (anatomy) | |
|---|---|
 |
|
| Second cervical vertebra, or epistropheus, from above. | |
 |
|
| Posterior atlantooccipital membrane and atlantoaxial ligament. (Axis visible at center.) | |
| Gray's | subject #21 99 |
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. It is the bone responsible for death in Judicial Hanging as the odontoid process usually breaks and hits the medulla oblongata, damaging the vital centres.
|
Contents
|
The body
The body is deeper in front than behind, and prolonged downward anteriorly so as to overlap the upper and front part of the third vertebra.
It presents in front a median longitudinal ridge, separating two lateral depressions for the attachment of the Longus colli muscles.
Its under surface is concave from before backward and convex from side to side.
Other features
The dens, or odontoid process, exhibits a slight constriction or neck where it joins the body.
The pedicles are broad and strong, especially in front, where they coalesce with the sides of the body and the root of the odontoid process. They are covered above by the superior articular surfaces.
The laminae are thick and strong, and the vertebral foramen large, but smaller than that of the atlas.
The transverse processes are very small, and each ends in a single tubercle; each is perforated by the transverse foramen, which is directed obliquely upward and laterally.
The superior articular surfaces are round, slightly convex, directed upward and laterally, and are supported on the body, pedicles, and transverse processes.
The inferior articular surfaces have the same direction as those of the other cervical vertebrae.
The superior vertebral notches are very shallow, and lie behind the articular processes; the inferior lie in front of the articular processes, as in the other cervical vertebrae.
The spinous process is large, very strong, deeply channelled on its under surface, and presents a bifid, tuberculated extremity.
Additional images
-
Median sagittal section through the occipital bone and first three cervical vertebræ.
-
Sagittal section of nose mouth, pharynx, and larynx.
-
Axis on x-ray
See also
External links
- Netter, Frank. Atlas of Human Anatomy, "High Cervical Spine: C1-C2"
This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.
|
||||||||||||||||||||||||||||||||||||||
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
Translations:
Top
Axis
idioms:
- X axis X-akse
- Y axis Y-akse
Nederlands (Dutch)
as, middellijn, spil, tweede halswervel, witgestippeld hert
idioms:
- X axis axe des x, axe des abscisses
- Y axis axe des y, axe des ordonnées
idioms:
- X axis Abszissenachse, X-Achse
- Y axis Ordinatenachse, Y-Achse
Ελληνική (Greek)
n. - (μαθημ.) (νοητός) άξονας
idioms:
- X axis άξονας του Χ, οριζόντιος άξονας
- Y axis άξονας του Υ, κάθετος άξονας
idioms:
- X axis ascisse
- Y axis ordinate
Português (Portuguese)
n. - eixo (m), áxis (m) (Zool.)
idioms:
- X axis eixo X
- Y axis eixo Y
Русский (Russian)
ось, гитлеровская Германия и ее союзники
idioms:
- X axis икс-координата
- Y axis игрек-координата
idioms:
- X axis eje de abscisas, eje de las equis
- Y axis eje de ordenadas, eje de las y
Svenska (Swedish)
n. - axel (matem.,fys.)
中文（简体）(Chinese (Simplified))
轴, 主茎, 轴线, 光轴
idioms:
- X axis 坐标X轴
- Y axis 坐标y轴
中文（繁體）(Chinese (Traditional))
n. - 軸, 主莖, 軸線, 光軸
idioms:
- X axis 座標X軸
- Y axis 座標y軸
日本語 (Japanese)
n. - アクシスジカ, 軸, 軸椎骨, 枢軸, 中心線
adj. - 日独伊枢軸の
العربيه (Arabic)
(الاسم) محور, حلف, الفقره الثانيه في العنق
עברית (Hebrew)
n. - ציר, חוליית הצוואר השנייה, ציר הסימטריה - קו המחלק גוף סימטרי באופן סימטרי, ברית בין מדינות המכוונת להצטרפות מדינות נוספות
If you are unable to view some languages clearly, click here.
Post a question - any question - to the WikiAnswers community:
Copyrights:
American Heritage Dictionary
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
Read more
McGraw-Hill Dictionary of Architecture & Construction
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc. All rights reserved.
Read more
Oxford Dictionary of Sports Science & Medicine
The Oxford Dictionary of Sports Science & Medicine. Copyright © Michael Kent 1998, 2006, 2007. All rights reserved.
Read more
Dictionary of Cultural Literacy: Geography
The New Dictionary of Cultural Literacy, Third Edition Edited by E.D. Hirsch, Jr., Joseph F. Kett, and
James Trefil. Copyright © 2002 by Houghton Mifflin Company. Published by Houghton Mifflin. All rights reserved.
Read more
Taylor's Dictionary for Gardeners
Taylor's Dictionary for Gardeners, by Frances Tenenbaum. Copyright © 1997 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
Read more
Word Tutor
Copyright © 2004-present by eSpindle Learning, a 501(c) nonprofit organization. All rights reserved.
eSpindle provides personalized spelling and vocabulary tutoring online; sign up free. Read more
eSpindle provides personalized spelling and vocabulary tutoring online; sign up free. Read more
Dictionary of Cultural Literacy: Science
The New Dictionary of Cultural Literacy, Third Edition Edited by E.D. Hirsch, Jr., Joseph F. Kett, and James Trefil. Copyright © 2002 by Houghton Mifflin Company. Published by Houghton Mifflin. All rights reserved.
Read more
Oxford Dictionary of Biochemistry
Oxford University Press. Oxford Dictionary of Biochemistry and Molecular Biology © 1997, 2000, 2006 All rights reserved.
Read more
Saunders Veterinary Dictionary
Saunders Comprehensive Veterinary Dictionary 3rd Edition. Copyright © 2007 by D.C. Blood, V.P. Studdert and C.C. Gay, Elsevier. All rights reserved.
Read more
Mosby's Dental Dictionary
Mosby's Dental Dictionary. Copyright © 2004 by Elsevier, Inc. All rights reserved.
Read more
Random House Word Menu
© 2010 Write Brothers Inc. Word Menu is a registered trademark of the Estate of Stephen Glazier.
Write Brothers Inc.
All rights reserved.
Read more
Bradford's Crossword Solver's Dictionary
Collins Bradford's Crossword Solver's Dictionary © Anne Bradford, 1986, 1993, 1997, 2000, 2003, 2005, 2008
HarperCollins Publishers
All rights reserved.
Read more
Wikipedia on Answers.com
This article is licensed under the Creative Commons Attribution/Share-Alike License. It uses material from the Wikipedia article Axis (anatomy).
Read more
