Anatomy-Lexicon

Body cavities

introduction

Body cavities are cavities that occur in different areas of the body. A body cavity can only be designated as such when it has been completely enclosed by the trunk wall. This results in a topographical, that is, a position-dependent division of the body cavities.

Topographical classification:

Chest cavity (Cavitas thoracis)
Abdominal cavity (Cavitas abdominalis)
Pelvic cavity (Cavitas pelvis)

These cavities are only clearly delimited between the thoracic and abdominal cavities.

Here the diaphragm, which is so important for breathing, forms a clear anatomical boundary structure between these two cavities. Such an anatomical boundary is absent in the abdominal or pelvic cavity. One speaks here of a continuous transition of the caves.

Serous caves

Under serous cavities one understands Crevices, the within the topographical one just described Body cavities lie. you are lined by a two-layer tunica serosa, which are decisive for Movability of the internal organs contributes. This happens through a film of liquid that lies on top of it. Serous cavities can also be classified as follows:

Pleural cavity (Cavitas pleuralis)
Pericardial cavity (Cavitas pericardiaca)
Peritoneal cavity (Cavitas peritonealis)
- Peritoneal cavity of the abdomen (Cavitas peritonealis abdominis)
- Peritoneal cavity of the pelvis (Cavitas peritonealis pelvis)

Around the abdominal cavity (Cavitas abdominalis) not with the peritoneal cavity of the abdomen (Cavitas peritonealis abdominis), the latter is also referred to as Abdomen.

Construction of serous cavities

As mentioned above, form serous cavities from the tunica serosa. This consists of two parts or "leaves". The structure of serous cavities is always the same.

the visceral sheet (Serosa visceralis) surrounds the organs
the parietal sheet (Serosa parietalis) forms the outer demarcation. It also lines the wall of the serous cavity.

In the Naming of the "leaves" is needed again Subdivision in the various serous cavities.

In the Peritoneal cavity (Cavitas peritonealis) one speaks of Visceral peritoneum as visceral sheet and from Parietal peritoneum as parallel leaf
The Pleural cavity (Cavitas pleuralis) on the one hand has a Visceral pleura as a visceral sheet and a Parietal pleura as a parietalis leaf
The Pericardial cavity has a Pericardium serosum. An additional term is used for the term “serosum”, as there is also a pericardium fibrosum for the outer part of the pericardium

Often a little difficult to understand, but they are very important Serosa Ratios. They often serve as a Pathways of vessels and nerves. For this to be possible, they are completely enclosed by the serosa.

The area in which the terms of the visceral and parietal leaves discussed above merge is called the meso. They have a very special function. It is therefore a duplication of the serosa. The attachment of this duplication to the fuselage wall is known as a radix. Pathways that run in strands of connective tissue and thus also connect organs with each other are also called ligaments (Ligaments). This term is also known from the anatomy of the musculoskeletal system. However, the strength of these ligaments cannot be compared with the ligamentous ligaments of the ankle or wrist. The serous fluid that is located between the two leaves also has an important physiological significance. So it has a capillary adhesion, which causes a sliding cohesion of the contact surfaces. By definition, serous fluid is understood to be a transudate, i.e. a filtrate of the blood plasma without a cellular component.

Fine structure of the tunica serosa

Since the Tunica serosa the Basic structure for each serous cavity forms, it makes sense to theirs construction to describe in more detail. As mentioned above, it consists of 2 layers:

Serous epithelium (Lamina epithelialis)

Single-layer cell structure, which consists primarily of flat mesothelium, a connective tissue formed from the embryonic period

Serosan connective tissue (Lamina propria)

it consists of one Network of blood and lymph vessels

But how are these important serous membranes supplied with blood? As with organs, the (small) Blood vessels and nerves in the connective tissue to the serous membranes. So the location of these structures "Submesothelial".

Another interesting aspect is that Supply of the visceral or parietal "leaf" With Nerve tissue. Because the visceral “leaf” is considered insensitive to pain, while the parietal “leaf” is the opposite and is very sensitive to pain.

The Nerve supply the Parietal pleura is through the Phrenic nerve taken over, which also supplies the diaphragm.

That too Pericardium (Pericardium) is inherited by the Phrenic nerve provided. Additionally through parts of the vagus nerve.

The parietal "sheet" of the peritoneal cavity is also here by the Phrenic nerve supplied, but from a different segment.

Formation of serous cavities

All of the body cavities described arise from a uniform body cavity, the so-called Zolom Cave. By Formations of the lungs, kidneys, heart etc. towards the end of the third embryonic week from this room the pleural, peritoneal and pericardial cavities develop. Through the progressive development of the diaphragm arises the anatomical boundary structurewhich leads to a separation of the peritoneal cavity from the thoracic cavity. The connection of the pleural cavity with the pericardial cavity also becomes a serous cavity through the merging of the two "pleuropericardial folds".

Bleeding in body cavities

Bleeding in body cavities, such as the chest or abdominal cavity, can occur for a variety of reasons. A possible cause can be a traumatic experience, such as a traffic accident. A strong impact can injure internal organs, which then bleed into the corresponding body cavity.

Bleeding into a body cavity often shows typical symptoms, such as circulatory failure, palpitations or disturbances of consciousness.

The internal bleeding is treated with a surgical procedure in which the bleeding is to be stopped. In addition, acute complaints, such as circulatory failure due to the administration of medication, are treated. In the case of internal bleeding, it is important that the patient is treated as quickly as possible, otherwise the blood loss will be too great. In this case, there is a risk of complete circulatory collapse, which if left untreated can lead to death.

Fluid retention in body cavities

Liquids can collect in the various body cavities. On the one hand, this can be blood if an organ is injured and bleeds into the cavity.

However, if no accident or the like has occurred, it can also be water, which is located in the abdomen, for example. This water belly will Ascites and indicates, for example, liver dysfunction. Too few proteins are produced by the body, so that the water flows out of the vessels and collects in the stomach. This accumulation of fluid is also known as effusion and can also occur in other body cavities. Depending on the location, this is referred to as a pleural effusion (fluid in the chest cavity) or pericardial effusion (fluid in the pericardium).

Metastasis to the body cavity

Metastases are usually smaller offshoots of a primary tumor. These can form in all possible parts of the body, including in body cavities. In this case one speaks of cavitary metastases (cavitas = cave). In general, such metastasis is rare and usually affects the abdominal cavity. This type of metastasis mainly arises from the spread of the tumor cells of the primary tumor.

This spread is triggered by organ movement or the rushing blood stream. The detached cancer cells settle again at any point and begin to grow, for example in the abdomen on the peritoneum.

Tumor metastases that arise in this way are called Implantation metastases designated.