Abdomen

abdomen it is the portion of body located between thorax and pelvis, in mammals, that it contains in its interior the abdominal cavity.

The abdominal cavity is separated of the torácica by diaphragm and it presents/displays a disposition of vísceras intraabdominal in such a way that it is possible to identify them with the lines of general division of the anatomical regions of the abdomen.

Almost all the vísceras that the abdominal cavity contains belong to digestive apparatus.

The abdominal cavity is covered inner by a called membrane peritoneo.

External anatomical regions of the abdomen

With clinical aims, like the description of pain, tumors and incisions, the abdomen is divided in regions that are defined by lines in the surface of previous the abdominal wall. Generally, nine regions cut by two horizontal lines and two verticals are delineated:

• A) and B) The vertical line of each side corresponds to line to clavicular average, right and left respectively. When one extends downwards arrives at the average inguinal point, halfway between sínfisis of pubis and it pricks anterosuperior ilíaca.
• C) subcostal Line, that it happens through the inferior edge of ribs. Also transpilórica line is called, halfway between the jugular recess and the superior part of the sínfisis of pubis.
• C) inferior Line transversa or line to intertubercular, one draws up between tubercles of the ilíacas crests.

Using these four lines nine anatomical regions are defined that are:

1. Right Hipocondrio: In this region it is located liver and biliary routes.
2. Epigástrica region or epigastrio: It is the zone of stomach.
3. Left Hipocondrio: Here it is located bazo.
4. Region of the emptiness, flank, lumbar or lateral right: It is the region of colon ascending.
5. Region of mesogastrio or umbilical: Region of the thin intestine.
6. Region of the emptiness, left lateral flank or: It is the region of colon descendent.
7. Right iliaca grave or right inguinal region:It is the region of the blind person and appendix.
8. Hipogastrio or suprapúbica region: It is the region of vejiga urinary when she is full.
9. Left iliaca grave or left inguinal region: It is the region of the sigmoideo colon or sigma.

This relation between external anatomical region of the abdomen and intraabdominal vísceras is not exact, because the abdominal vísceras move and exceed the mentioned limits, but it serves like general indicator. On the other hand, pain in some is of frequent use in the clinic to refer the pointed regions, although it is necessary to consider that the location of the visceral pain is poor and the phenomenon of the referred pain can be given, in that it hurts a moved away zone of the responsible víscera.

Embryonic development of the intraadominales vísceras

The ventral incurvación of the leaves of mesoderm lateral it causes that the abdominal celómica cavity forms. The esplacnopleural leaf surrounds to the derivative by endoderm and it maintains his union with the later wall, forming "I pull" (mesenterio, mesogastrio, mesocolon) that is by where the vascular and nervous contribution will enter. Many of the details of the intrincate relation between mesos, spaces and vísceras can only be understood from a embriológico point of view, for example, the transcavidad of epiplones.

General topography of the organs of the abdomen:

One first division is in supramesocólicas and inframesocólicas vísceras, according to they are left over mesocolon transverso (stomach, liver, bazo) or underneath (thin intestine, kidneys, suprarrenales). This division has practical importance because the abdominal operations vary from one to another one. Another division is as well in intraperitoneales or retroperitoneales vísceras (, primary or secondarily retroperitoneales). The peritoneales vísceras are within the peritoneal cavity by virtue of their endodérmico origin and of I pull suficientemte long. The retroperitoneales derive from the mesoderm (intermediate mesoderm in the case of the kidney). Also they can be intraperitoneales that soon is fixed (for example, second portion of duodeno and it leaves from páncreas), by the turns and rotations of the digestive apparatus his the later celómica wall pulls well is had left patch.

General irrigation of lor abdominal organs

• Arterial irrigation: The arterial vascularización of the abdominal vísceras comes from the abdominal portion of artery aorta (that it arrives at the abdomen through the hiatus from diaphragm, at level of vertebra T12), immediately it emits the inferior diafragmáticas arteries and the average suprarrenales arteries. More of great volume it gives three heavy uneven trunks for the intraperitoneales vísceras, from that other many arteries arise. Craneal it is celíaco trunk (it irrigates liver, stomach and bazo), followed of superior mesentérica artery (internal thin) and of the inferior mesentérica artery (heavy intestine). For the retroperitoneal space it emits pairs of arteries like the renales arteries (for the kidneys), lumbar (later abdominal wall) and gonadales (testicular or ovarian). Of great volume average is divided in the two ilíacas arteries common (left and right) and in the sacred artery.
• Venous return: The venous return of the abdomen corresponds to vein digs inferior, that it is from the fusion of the two common ilíacas veins. It receives the renales veins, lumbar and gonadales, and it crosses diaframa upon the liver. The venous return of the intestinal handles - to take blood that takes built-in products of digestion and that cannot thus pass to the circulatory torrent sistémico- comes together in the mesentéricas veins, superior and inferior, which along with the gastric veins and the esplénica vein form the trunk of vein carries that it enters the liver. The vein carries ramifica in the interior of parénquima hepático (system behaves, that ramifica twice). Once the blood of the vein carries is treated by the liver, in the hepáticos sinusoides, it comes together in the hepáticas veins that end at the vein digs inferior, that it leads it to the right auricle. In other words, the blood that gathers products of the digestion is lead directly towards the vein digs, but which it does through the liver by means of the system it carries. Great part of the hepáticos problems comes from an alteration in this system carries hepático.
• Lymphatic Vascularización: The lymphatic circulation gathers lymph coming from the digestive apparatus and of the inferior extremities in the denominated cistern of quilo, located in the later abdominal wall, between the artery aorta and spine at T12-L1 level. It happens to mediastino later by the aortic orifice. In addition, they present/display a series of lymphatic ganglia that they accompany in general the great arteries, or they are located in hilio of the organs.

General Inervación of the abdominal organs

The inervación of the abdominal vísceras is the responsibility of both component of vegetative nervous system likeable and parasimpático. The likeable nervous system of vísceras abdominal it comes preferredly from the esplácnicos nerves.

The esplácnicos nerves are three nerves to each side. They are originated in the likeable chain of the thorax: the greater one of gánglios T5-T10, the T11-T12 minor, and the inferior one of T12. They finish, well doing synapse or happening towards the víscera, in the celíacos ganglia (to both sides of the exit of the celíaco trunk of the aorta), mesentéricos or renales. The lumbar esplácnicos nerves (L1-L5) and the ganglia mesentérico superior and inferior complete the likeable inervación of the abdomen. They reach the vísceras with the arteries, walking fibers in the accidental one. The parasimpática inervación of all the embryonic derivatives of the previous and average intestine comes from vague nerve, from esophagus until the left end of the colon transverso. The distal part of the colon transverso, the descendent colon, the sigmoides and the rectum receive parasimpática inervación coming from the sacred parasimpático nucleus located in spinal marrow sacred, located between the spinal segments S2 to S4.

Musculatura of the previous wall of the abdomen

• Muscle transverso of the abdomen
• Internal muscle oblícuo of the abdomen
• External muscle oblícuo of the abdomen
• Straight muscle of the abdomen

The abdomen in the animals