Body cavities

Introduction

Body cavities are hollow spaces that occur in different areas of the body. A body cavity can only be described as such when it is completely enclosed by the torso wall. This results in a topographic, i.e. a position-dependent division of the body cavities.

Topographical classification: Thoracic cavity (Cavitas thoracis) Abdominal cavity (Cavitas abdominalis) Pelvic cavity (Cavitas pelvis) A clear distinction between these cavities exists only between the thoracic and abdominal cavity. Here, the diaphragm, which is so important for breathing, forms a clear anatomical boundary structure between these two cavities. Such an anatomical boundary is missing in the abdominal and pelvic cavities. One speaks here of a continuous transition of the cavities.

• Thoracic cavity (Cavitas thoracis)
• Abdominal cavity (Cavitas abdominalis)
• Pelvic cavity (Cavitas pelvis)

Serious caves

Serous caves are fissure spaces that lie within the topographic body cavities just described. They are lined by a two-layer tunica serosa, which contributes significantly to the displaceability of the internal organs. This is done by 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) In order not to confuse the abdominal cavity (Cavitas abdominalis) with the peritoneal cavity of the abdomen (Cavitas peritonealis abdominis), the latter is also called the abdominal cavity.

• 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)
• Peritoneal cavity of the abdomen (Cavitas peritonealis abdominis)
• Peritoneal cavity of the pelvis (Cavitas peritonealis pelvis)
• Peritoneal cavity of the abdomen (Cavitas peritonealis abdominis)
• Peritoneal cavity of the pelvis (Cavitas peritonealis pelvis)

Construction of serous caves

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

The visceral leaf (Serosa visceralis) surrounds the organs the parietal leaf (Serosa parietalis) forms the outer boundary. It also lines the wall of the serous cavity. The naming of the “leaves” again requires a subdivision into the different serous cavities.

In the peritoneal cavity (Cavitas peritonealis) one speaks of the peritoneum viscerale as visceral leaf and of the peritoneum parietale as parietal leaf The pleural cavity (Cavitas pleuralis) has on the one hand a pleura visceralis as visceral leaf and a pleura parietalis as parietal leaf The pericardial cavity has a pericardium serosum The term “serosum” is used as an additional designation, since there is also a pericardium fibrosum for the outer part of the pericardium. They often serve as conduits for vessels and nerves. To make this possible, they are completely enclosed by the serosa.

• The visceral leaf (Serosa visceralis) surrounds the organs
• The parietal leaf (Serosa parietalis) forms the outer boundary. It also lines the wall of the serous cavity.
• In the peritoneal cavity (Cavitas peritonealis) one speaks of the visceral peritoneum as visceral leaf and of the parietal peritoneum as parietal leaf
• The pleural cavity (Cavitas pleuralis) has on the one hand a visceral pleura as visceral leaf and a parietal pleura as parietal leaf
• The pericardial cavity has a pericardium serosum. The term “serosum” is used as an additional designation, since there is also a pericardium fibrosum for the outer part of the pericardium

The area in which 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 trunk wall is called a radix.

Conduction pathways that run in connective tissue strands and thus also connect organs are also called ligaments (ligamenta). This term is also known from the anatomy of the musculoskeletal and supporting apparatus. The strength of these ligaments, however, cannot be compared to the ligaments of the ligamentous apparatus of the ankle or wrist. The serous fluid between the two leaves also has an important physiological significance. For example, it has capillary adhesion, which causes a sliding cohesion of the contact surfaces.By definition, serous fluid is a transudate, i.e. a filtrate of the blood plasma without cellular content.