Functional and topographic anatomy of the diaphragm

The relative position of the diaphragm is clinically relevant. The topographical references help with orientation in the thorax and interpretation of X-ray images. The diaphragmatic domes are clearly visible here.

Due to the curvature, a gap in the pleura (pleura) between the chest wall and the diaphragm, the recessus costodiaphragmaticus, sinks. A further gap is created independently of the diaphragmatic curvature between the ribs and the back wall of the sternum on the one hand and the front wall of the pericardium on the other. During deep inhalation, the lung shifts into these reserve gaps.

The projection of the diaphragm onto the trunk depends primarily on the breathing position. In the exhalation position, the diaphragm rises up to the 4th rib, and with maximum inhalation it can be lowered on the right almost to the 7th rib. However, the actual diaphragm position still depends on the constitution type, age and sex of the person.

In addition, because of the asymmetrical position of the heart, it is lower on the left than on the right. Inhalation causes not only a lowering of the diaphragm, but also a flattening of both domes. The extent of movement of the diaphragm during inspiration can be estimated by the displacement of the palpable edge of the liver.

The displacement of breath is approximately six to seven centimeters. The diaphragm is higher in a lying position than in a standing position due to the pressure of the abdominal organs. The diaphragm is higher in a corpse because of the loss of tone than in a living person when breathing out (see above for the neighborhood relationships of the organs).

The diaphragm (diaphragm) is a huge muscle with a large central tendon attachment. The diaphragm separates the abdomen from the thorax and is a very important muscle for breathing in general. The diaphragm is particularly important for inhalation (inspiration), as it creates a negative pressure through muscle contraction and ensures that the abdominal organs are pressed downwards, thus creating more space for the air flowing into the lungs so that the lungs can load the red blood cells with oxygen.

Thus with each breath a diaphragmatic breathing takes place, which is vital to fill the lungs and thus the entire body circulation properly with oxygen and fresh air. Diaphragmatic breathing is often equated with the term abdominal breathing. In the end, diaphragmatic breathing is simply a matter of creating more space for the lungs to unfold by contracting the diaphragm and allowing them to expand a little.

As the diaphragm presses down, the abdominal organs are shifted into the abdomen and the abdominal wall bulges slightly. You can follow this with your hands when you place them on your stomach and then consciously breathe in and out deeply. This is called abdominal breathing.

This form of breathing is caused by diaphragmatic breathing and is therefore often used as a synonym for it. Diaphragmatic breathing is contrasted with thoracic breathing, in which the diaphragm contracts only minimally and the chest widens mainly upwards to allow the lungs the necessary expansion to absorb the freshly inhaled air. In the case of a diaphragmatic hernia or so-called hernia, parts of the abdominal organs shift into the chest cavity due to congenital or acquired weaknesses.

This form of hernia is also called internal hernias, as they are not visible to the doctor from the outside. A diaphragmatic hernia always occurs at the place of least resistance – “Locus minoris resistentiae”.These form the natural passages and the muscle-free parts of the diaphragm (Larey cleft, Bochdalek triangle). If the intra-abdominal pressure is increased, abdominal organs can break through into the chest cavity.

The danger here is entrapment of intestinal loops with threatening intestinal obstruction. The consequences are severe abdominal pain of unclear cause. In this case a quick operation is indicated, otherwise there is a danger to life.

The most frequent hernia and entry portal is the hiatus oesophageus with 90% of cases. In most cases, the end of the esophagus “slides” with the stomach entrance (cardia) through the hiatus into the chest (axial hiatus hernia or sliding hernia; about 85% of all hiatus hernias). Typical symptoms are heartburn, acidic belching and a feeling of pressure behind the breastbone after eating, up to nausea, vomiting, shortness of breath and functional heart complaints.

Congenital diaphragmatic hernias are found with a relatively high probability of 1:2000 births in the Bochdalek triangle. The cause is the incomplete closure of the diaphragm during embryonic development. Abdominal viscera pass through here and press on the heart and lungs.

A quick operation is also necessary in this case due to acute danger to life. Prenatal ultrasound diagnostics can indicate the defect. The localization is almost always on the left side. The reason is simple: the liver is located on the right. A hernia in the trigonum sternocostale, i.e. behind the breastbone (morgagnia, parasternal hernia), is possible, but much less frequent.