ABSTRACT
There are a number of organs in or near the abdomen and it is convenient to consider them as two groups. The first group is an unpaired set of three organs, all of which began as intra abdominal structures. The second group consists of three paired sets of organs, all of which began as retro peritoneal structures. The groups are considered separately. In addition to these organs, there is a major artery, the abdominal aorta, which is situated in the posterior abdominal wall. This is important in diagnosis and is briefly considered also.
