What are Body Cavities?  

The potential spaces detected in the body of the animal is called the body cavity. The structure is found to possess organs and numerous structures and also contain fluid.  The dorsal and the ventral body cavities are the largest body cavities found in the human. The embryo of the mammals contains two body cavities called the extraembryonic coelom (lined by extraembryonic mesoderm) and the intraembryonic coelom (lined by somatic and splanchnic lateral plate mesoderm).  

Classification of Human Body Cavities

The human body cavities are distinguished into the dorsal body cavity and ventral body cavity.  

The dorsal body cavity encompasses the cranial cavity within the skull and spinal cavity enclosed by the spine. The skull contains the brain and spinal canal contains the spinal cord. Spinal cord is enclosed by the vertebral column. 

The ventral body cavity consists of the thoracic cavity surrounded by the ribcage and it possesses the heart and the lungs. The ventral cavity also includes the abdominopelvic cavity, which consists of the pelvic cavity and the abdominal cavity.  The abdominal cavity possesses the liver, stomach, kidneys, intestines, pancreas, gall bladder, and ureters. The pelvic cavity consists of the reproductive system, anus, and bladder. The thoracic cavity possesses three cavities including the two pleural cavities, the pericardial cavity, and the superior mediastinum. The pleural cavities are positioned on the side regions of the body, where one is positioned anterior to the spine and the other is present in the lateral region of the breast bone. The region between the two thoracic cavities is the superior mediastinum.  

Ventral body cavity and its Significance 

The region below the superior mediastinum has the pericardial cavity. The pericardial cavity roughly outlines the shape of the heart. The diaphragm is associated with the division of the thoracic and the abdominal cavity. The whole low half of the trunk is included in the abdominal cavity. The cavity anterior to the buttocks is considered as the pelvic cavity.  The pelvic cavity is identified to be funnel-shaped and is positioned inferior to the abdominal cavity.  The anterior cavity possesses two important subdivisions including the abdominopelvic cavity and the thoracic cavity.  The thoracic cavity is found to be a higher subdivision of the anterior cavity and is surrounded by the rib cage.  The thoracic cavity possesses the heart and the lungs positioned in the mediastinum.  The floor of the thoracic cavity is formed by the diaphragm and it mediates the separation of the more inferior abdominopelvic cavity. The abdominopelvic cavity is found to be the largest cavity and no membrane is associated with the division of the abdominopelvic cavity. 

Dorsal body cavity and its significance  

The dorsal body cavity consists of the spinal cavity and the cranial cavity. The cranial cavity is found to be bean-shaped and covers the region of the upper skull. The spinal cavity is a narrow, thread-shaped cavity positioned along the cranial cavity to the whole of the spinal cord.  The combination of the dorsal body cavity and the spinal cavity together forms the dorsal body cavity. The brain is positioned in the cranial cavity. The structures including the spinal and the cranial cavity are found to be continuous in nature. The spinal cord and the brain are guarded by the bones present in the vertebral column and the skull respectively. The cerebrospinal fluid also has a major role in protection as it provides cushioning to the brain and the spinal cord.  

Development of Body Cavity

The third week of the embryonic development marks the formation of the ectoderm, which is a neural tube formed by the layers of trilaminar germ disc.  This layer is found to elevate and undergo dorsal closure. The gut tube is found to roll up and undergo closure ventrally for the formation of a tube on the upper region of a tube. The mesoderm is considered as the other layer of the trilaminar germ discs, and it holds the lateral plate mesoderm and the tubes.  It is the middle layer of the germ disc, and it undergoes splitting for the formation of the visceral layer connected with the gut and the parietal layer. The primitive body cavity is the space identified between the parietal and the visceral cavity.  The folding of the lateral body cavity mediates the transaction of the cavity to the ventral region and undergoes fusion at the midline. The body cavity undergoes closing at all regions excluding the position of the connecting stalk. 

The lateral body wall mediates the pulling of the amnion such that the embryo is surrounded by the amnion. The connecting stalk becomes the umbilical cord, and it mediates the link between the placenta and the fetus. The visceral layer is associated with the formation of the visceral layer of the serous membrane enclosing the abdominal organs, heart, and lungs. The peritoneum is the serum membrane that is associated with the formation of the abdominal cavity, and it mediates the generation of the gut layers. The mesenteries are associated with serving as a pathway for the lymphatics, nerves, and vessels of the body. The ventral mesentery formed from the septum transversum is positioned only in the region present in the terminal position of the esophagus, the upper region of the duodenum, and the stomach. 

Function of the body cavity 

Body cavities withhold delicate internal organs. The ventral cavity supports various changes in the shape and size of the organ for carrying out their specialized function in the body. The anatomical structures are named based on their body cavity and the internal organization of the body cavity is sustained by the aid of sheaths, membranes, and various other structures.  The organs including the intestines, stomach, heart, and lungs can undergo contraction and relaxation without disturbing the function of other organs with the aid of the body cavity. 

Context and Applications 

This topic is significant in the professional exams for both undergraduate and graduate courses, especially for       

• Bachelor of Medicine 
• Bachelor of Surgery  

Related concepts  

Gastrovascular cavity, coelom