Final answer:
The smallest diameter of the thoracic pedicle is typically 4-6 mm. The thoracic vertebrae, to which ribs attach, number twelve and are located in the mid-spine. The atlas bone is the first cervical vertebra, crucial for head movement support.
Step-by-step explanation:
The smallest diameter of the thoracic pedicle typically ranges between 4-6 mm. The thoracic pedicle is a part of the thoracic vertebrae, of which humans have twelve. These are located in the middle portion of the spinal column. The ribs attach to the thoracic vertebrae, which is important in the structure of the rib cage that protects vital organs such as the heart and lungs.
The atlas bone is the first cervical vertebra of the spine, also known as C1. It plays a crucial role in supporting the skull and allowing the head to nod and rotate, acting as a pivot point for the skull and the spine.