APPENDIX [lat. appendix appendage; synonym worm-shaped shoot; appendix vermiformis (PNA), processus vermiformis (BNA, JNA)] — the shoot departing from a caecum. And. — rudimental organ. It is formed as a result of a differentiation of a caecum on two departments — actually the caecum and a narrow part which is its underdeveloped end. Such differentiation occurs at animals in the course of evolution in connection with character of food. The animals eating difficult digested vegetable food rich with cellulose have a big caecum and is absent And.; at eating on the food which is easily digested animal or mixed a caecum it is poorly developed. At the person and subhuman primates its distal end is strongly narrowed, turning into A. Appendiks in the form of a diverticulum with a narrow gleam and lymphoid submucosal accumulations is available only for the few vertebrata: at rodents (hares), at some predatory, at semi-monkeys (lemurs) and monkeys. At other vertebrata it is possible to track its homologs. So, cats have accumulations of an adenoid tissue in a caecum.
The person has length And. strongly varies. It averages 8 — 15 cm, seldom or never — 3 cm. The child has a ratio between length And. and length of a large intestine makes 1: 10, and a ratio between And. and length of all intestines — 1: 70 (at the adult respectively 1: 20 and 1: 115). On the first year of life And. considerably increases, then grows more slowly and by 5 years its length makes 7 — 8 cm, in 10 years — 9 cm, in 20 years — 9 — 12 cm. Diameter of the opening conducting from a caecum in A. (ostium appendicis vermiformis), makes about 5 mm. This opening is quite often closed by the fold reaching the maximum development in children at the age of 3 — 12 years (valvula processus vermiformis, BNA). Gleam And. at persons 50 years are more senior can sometimes partially or grow completely.
In the free region of a mesenteriolum A. Arteriya's vessels, the feeding A are located. (a. appendicularis), can have various options of branching (fig.) that plays a part at appendectomy. Vienna A. belongs (v. appendicularis) to system of an upper mesenteric vein and repeats the course of the artery of the same name. It is innervated And. from an upper mesenteric texture.
Situation A. it is connected first of all with an arrangement of a caecum. In most cases the appendix, as well as a caecum, lies in the right ileal hole, but can lie above, at a high arrangement of a caecum, and below, in a small basin, at its low situation.
Distinguish four main typical versions of the provision And.:
1. The descending situation (observed in 40 — 50% of cases). And. is located from a caecum from top to bottom and can go down in a cavity of a small pelvis.
2. Lateral situation — knaruzh from a caecum (observed in 25% of cases).
3. Medial situation — knutr from a caecum (observed in 17 — 20% of cases).
4. The ascending situation (observed approximately in 13% of cases), at Krom the end And. it is turned up and kzad from a caecum (retrocecal situation).
Same versions of the provision A. meet and at a retroperitoneal arrangement of A. Verkhushk A. can reach a front surface of a kidney, a cross colon, a gall bladder or the right appendages of a uterus, a rectum, a bladder.
Wall And. the wall of intestines consists of the same layers, as. In it distinguish a mucous membrane, a submucosa, muscular and serous covers. In a submucosa And. lymphoid accumulations in the form of follicles (folliculi lymphatici aggregati appendicis ver-miformis) are located. Adenoid tissue of A. at the newborn it is developed poorly. On 3 — the 14th day of life in And. there are limf, follicles which at the child there is a lot of that they form conglomerates. They reach the maximum development by 10 — 14 years of life, then there comes their involution. Some authors consider that these accumulations of follicles have important functional value, calling them «tonsilla appendicularis». And. as «the intestinal almond» gives bystry reactions from the follicular device at dysfunction of a caecum, especially at inflammatory processes in it various origin, including in the presence of foreign bodys (fecal stones, stones, etc.).
The ampere-second is located with the expressed mesenteriolum (mesoappendix) intraperitoneally; retroperitoneal arrangement And. meets extremely seldom.
Bibliography: Andronesku A. Anatomy of the child, the lane from Romanians., Bucharest, 1970; G. K Korning. Topographical anatomy, the lane with it., page 440, M. — L., 1931; Ostroverkhov G. E., Lubotsky D. N. ibomash Yu. M. Kurs of operational surgery and topographical anatomy, page 566, M., 1964.
I. I. Novikov.