When we talk about abdominals, there is an almost automatic association with the image of a muscular, flat and defined belly; the so-called six-pack!
In reality, the word "abdominal" is not a real noun, but a qualifying adjective. By abdominal we mean anything that has to do with the region of the abdomen, or the area bounded forward by the anterior abdominal wall, closed at the top by the diaphragm (which separates it from the chest cavity), and continued below with the pelvic cavity . The organs of the digestive tract are contained in the abdominal cavity and is completely covered by a serous membrane called peritoneum. Thus, there are abdominal girdle muscles, abdominal cavity organs, abdominal pain, etc.
In reality, the belief that abdominal muscles are synonymous with the "six-pack" is a beautiful and good distortion. This is justifiable by the fact that many other bundles assigned to the mobility / approach of the trunk and the hip are inserted in the abdominal girdle. Among other things, to be picky, the rectum itself does not have 6 groups of beams divided longitudinally and laterally, but 8!
Ultimately, the abdominal region includes:
Rectum of the abdomen
2 Transverse abdomen
2 External oblique
2 Internal oblique
2 Square of the loins
2 Great psoas
2 Small psoas.
A big difference!