quadratus lumborum
The transversus abdominis.
Some floor exercises, if done correctly, do strengthen abdominal muscles. Crunches and situps do this. Some yoga or pilates positions accomplish this as well.
abdominal muscles
I'm no expert but one difference is your external abdominal muscles are voluntary and intestinal muscles are involuntary.
Tendons.
ligamints
tendons
An abdominal wall is the layer of muscles which surrounds the abdominal cavity and contains the abdominal organs.
The causes of loose abdominal muscles include extreme weight loss and pregnancy.
The baby is located behind the abdominal muscles, within the uterus, which is situated in the pelvic cavity. The abdominal muscles form a protective layer around the uterus and other internal organs. As the pregnancy progresses, the growing baby pushes against the abdominal wall, but it remains inside the uterus, separated from the abdominal muscles.
tendons
Attaches them together.