Infectious diseases are caused by microorganisms such as viruses, bacteria, fungi or parasites and can spread between individuals. 1  Infectious diseases are caused by microorganisms such as viruses, bacteria, fungi or parasites. 2  Microorganisms that cause disease are collectively called pathogens.
The Abdominopelvic Cavity The abdominopelvic cavity extends from the diaphragm to the pelvis. It is subdivided into a superior abdominal cavity and an inferior pelvic cavity (Figure 1-11a,c). The abdominopelvic cavity contains the peritoneal cavity, a chamber lined by a serous membrane known as the peritoneum.
The ventral cavity is on the front of the trunk. The diaphragm (the main muscle of breathing) divides the ventral cavity into two simple subcavities: thoracic and abdominal. 1  thoracic cavity which is surrounded by the ribs and chest muscles is superior (above) to the diaphragm and abdominopelvic cavity.