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 known as the 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.

Structure

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.

Dens

The dens, also odontoid process or peg, is the most pronounced feature, and exhibits a slight constriction or neck where it joins the main body of the vertebra. The dens is a protuberance (process or projection) of the axis (second cervical vertebra). The condition, where the dens is separated from the body of the axis, is called os odontoideum, and may cause nerve and circulation compression syndrome. On its anterior surface is an oval or nearly circular facet for articulation with that on the anterior arch of the atlas. On the back of the neck, and frequently extending on to its lateral surfaces, is a shallow groove for the transverse atlantal ligament which retains the process in position. The apex is pointed, and gives attachment to the apical odontoid ligament; below the apex the process is somewhat enlarged, and presents on either side a rough impression for the attachment of the alar ligament; these ligaments connect the process to the occipital bone.

Anatomy

Anatomy is the branch of biology concerned with the study of the structure of organisms and their parts. In some of its facets, anatomy is related to embryology and comparative anatomy, which itself is closely related to evolutionary biology and phylogeny.Human anatomy is one of the basic essential sciences of medicine.

The discipline of anatomy is divided into macroscopic and microscopic anatomy. Macroscopic anatomy, or gross anatomy, is the examination of an animal's body parts using unaided eyesight. Gross anatomy also includes the branch of superficial anatomy. Microscopic anatomy involves the use of optical instruments in the study of the tissues of various structures, known as histology, and also in the study of cells.

The history of anatomy is characterized by a progressive understanding of the functions of the organs and structures of the human body. Methods have also improved dramatically, advancing from the examination of animals by dissection of carcasses and cadavers (corpses) to 20th century medical imaging techniques including X-ray, ultrasound, and magnetic resonance imaging.

Anatomy (Stan Ridgway album)

Anatomy is an album by Stan Ridgway, released in October 1999 through Ultramodern/New West Records. The disc includes three songs, "Camouflage," "I Wanna Be A Boss," and "The Roadblock," which were recorded live at the Strand in Los Angeles on November 2, 1991. They are available in Liquid Audio format.

Track listing

All tracks composed by Stan Ridgway except "Sixteen Tons" by Merle Travis.

Credits

References

Menippean satire

The genre of Menippean satire is a form of satire, usually in prose, which has a length and structure similar to a novel and is characterized by attacking mental attitudes rather than specific individuals or entities. Other features found in Menippean satire are different forms of parody and mythological burlesque, a critique of the myths inherited from traditional culture, a rhapsodic nature, a fragmented narrative, the combination of many different targets, and the rapid moving between styles and points of view.

The term is used by classical grammarians and by philologists mostly to refer to satires in prose (cf. the verse Satires of Juvenal and his imitators). Typical mental attitudes attacked and ridiculed by Menippean satires are "pedants, bigots, cranks, parvenus, virtuosi, enthusiasts, rapacious and incompetent professional men of all kinds," which are treated as diseases of the intellect. The term Menippean satire distinguishes it from the earlier satire pioneered by Aristophanes, which was based on personal attacks.

Axis (novel)

Axis is a science fiction novel by author Robert Charles Wilson, published in 2007. It is a direct sequel to Wilson's Hugo Award-winning Spin, published two years earlier. The novel was a finalist for the 2008 John W. Campbell Award.

Plot

Axis takes place on the new planet introduced at the end of Spin, a world the Hypotheticals engineered to support human life and connected to Earth by way of the Arch that towers hundreds of miles over the Indian Ocean. Humans are colonizing this new world — and, predictably, fiercely exploiting its resources, chiefly large deposits of oil in the western deserts of the continent of Equatoria.

Lise Adams is a young woman attempting to uncover the mystery of her father's disappearance ten years earlier. Turk Findley is an ex-sailor and sometimes-drifter. They come together when showers of cometary dust seed the planet with tiny remnant Hypothetical machines. Soon, this seemingly hospitable world becomes very alien, as the nature of time is once again twisted by entities unknown.

Cartesian coordinate system

A Cartesian coordinate system is a coordinate system that specifies each point uniquely in a plane by a pair of numerical coordinates, which are the signed distances to the point from two fixed perpendicular directed lines, measured in the same unit of length. Each reference line is called a coordinate axis or just axis of the system, and the point where they meet is its origin, usually at ordered pair (0, 0). The coordinates can also be defined as the positions of the perpendicular projections of the point onto the two axes, expressed as signed distances from the origin.

One can use the same principle to specify the position of any point in three-dimensional space by three Cartesian coordinates, its signed distances to three mutually perpendicular planes (or, equivalently, by its perpendicular projection onto three mutually perpendicular lines). In general, n Cartesian coordinates (an element of real n-space) specify the point in an n-dimensional Euclidean space for any dimension n. These coordinates are equal, up to sign, to distances from the point to n mutually perpendicular hyperplanes.

Yahoo! Axis

Yahoo Axis was a desktop web browser extension and mobile browser for iOS devices created and developed by Yahoo.

History

The browser made its public debut on May 23, 2012.

A copy of the private key used to sign official Yahoo browser extensions for Google Chrome was accidentally leaked in the first public release of the Chrome extension.

On June 28, 2013, Yahoo announced the discontinuation of the Axis.

Design

Axis replaces the standard search results page in other browsers with a menu of search results appearing as thumbnails at the top of the page. The menu allows the user to stay on the current page without navigating away from it.

Supported devices

Mobile browser

Desktop browser extension

See also

References