Final answer:
The external obliques, transverse abdominis, and erector spinae are the types of muscle described.
Step-by-step explanation:
The muscles located on either side of the rectus abdominis, running diagonally downward and inward from the lower ribs to the pelvis, are called external obliques. The deepest layer of muscle in the mid-section, which wraps the torso from front to back and from the ribs to the pelvis, is known as the transverse abdominis. The muscles and tendons that run from the neck to the low back are referred to as the erector spinae.
Learn more about Types of muscles in the mid-section