Final answer:
The thoracic cage, also known as the rib cage, includes the ribs, sternum, thoracic vertebrae, and costal cartilages. It protects vital organs such as the heart and lungs, supports upper limb movement, and plays a critical role in breathing.
Step-by-step explanation:
The thoracic cage, also known as the rib cage, is an essential part of the human skeletal system that includes the ribs, sternum, thoracic vertebrae, and costal cartilages. This bony structure forms the chest, or thoracic, portion of the body and provides several critical functions. Primarily, it protects the heart and lungs; these organs are shielded by the rib cage from physical trauma. Composed of 12 pairs of ribs attached to the thoracic vertebrae, the rib cage also supports the upper limbs and shoulder girdles. The sternum, divided into the manubrium, body, and xiphoid process, acts as the central anchor for the rib cage at the front of the body.
Ribs connect to the sternum with costal cartilages, aiding the rib cage's elasticity and allowing for the necessary expansion during respiration. The thoracic cage is integral to breathing as it changes in volume with the diaphragm’s movements. It also serves as an attachment point for various muscles that enable the diaphragm's movements, contributing to respiration and overall bodily functions related to the thoracic cavity. The rib cage's anatomical structure not only forms a protective cage but is pivotal to many systemic processes within the body.