Mesenteric organ

The human mesentery or mesentery organ is defined as the small intestinal mesentery, the mesocolon, mesosigmoid and mesorectum.^[1] Conventional teaching has dogmatically described the mesocolon as a fragmented structure, i.e. the small intestinal mesentery, transverse and sigmoid mesocolon all ‘terminate’ at their ‘insertion’ into the posterior abdominal wall.^[1] Recent advances in gastrointestinal anatomy have demonstrated that the mesenteric organ is in fact a single continuous structure from the duodenojejunal flexure to the level of the distal mesorectum. This far simpler concept has been shown to have significant implications.^[1,2]

History

The classical anatomical description of the mesocolon is credited to British surgeon Sir Frederick Treves in 1885.^[3] Treves is famously known for performing the first appendectomy in England in 1888 and was surgeon to both Queen Victoria and King Edward VII.^[4] He studied the human mesentery and peritoneal folds in 100 cadavers and described the right and left mesocolon as vestigial or absent in the human adult. Accordingly, the small intestinal mesentery, transverse and sigmoid mesocolon all terminated or attached at their insertions into the posterior abdominal wall.^[3-4] These assertions were indoctrinated into mainstream surgical, anatomical, embryological, and radiologic literature for more than a century and up to the recent present.^[5-6]

Organ

Organ may refer to the following:

Biology and medicine

Music

Organ, Hautes-Pyrénées

Organ (French pronunciation: ​[ɔʁɡɑ̃]) is a commune in the Hautes-Pyrénées department in south-western France.

See also

References

Organ (music)

In music, the organ (from Greek ὄργανον organon, "organ, instrument, tool") is a keyboard instrument of one or more divisions, each played with its own keyboard, played either with the hands or with the feet. The organ is a relatively old musical instrument, dating from the time of Ctesibius of Alexandria, who is credited with inventing the water organ. It was played throughout the Greek and Roman world, particularly during races and games. During the early medieval period it spread from the Byzantine Empire, where it continued to be used in secular and imperial court music, to Western Europe, where it gradually assumed a prominent place in the liturgy of the Catholic Church. Subsequently it re-emerged as a secular and recital instrument.

Overview

Pipe organs use wind moving through pipes to produce sounds. Since the 16th century, pipe organs have used various materials for pipes, which can vary widely in timbre and volume. The pipes are divided into ranks and controlled by the use of hand stops and combination pistons. Although the keyboard is not expressive as on a piano and does not affect dynamics (pressing a key only turns the sound on or off), some divisions may be enclosed in a swell box, allowing the dynamics to be controlled by shutters. Some organs are totally enclosed, meaning that all the divisions can be controlled by one set of shutters. Some special registers with free reed pipes are expressive. These instruments vary greatly in size, ranging from a cubic yard to a height reaching five floors, and are built in churches, synagogues, concert halls, and homes. Small organs are called "positive" (easily placed in different locations) or "portative" (small enough to carry while playing). Increasingly hybrid organs are appearing in which pipes are augmented with electronic additions. Great economies of space and cost are possible especially when the lowest (and largest) of the pipes can be replaced.