Thoracic Cage EDU - Module 2 > Thorax & Spine > Thorax & Spine Thoracic cage • Protects the chest organs (the heart and lungs). Main Structures: The sternum (aka, breastbone) lies anteriorly. 12 thoracic vertebrae lie posteriorly. 12 ribs articulate with the thoracic vertebrae. Sternum • Manubrium (superiorly) • Body (long and flat, middle portion) • Xiphoid process - Easily injured during chest compression (for CPR). • Sternal angle - Where manubrium and body meet - Easily palpated to find rib 2 • Sternal indentations: - Jugular notch (aka, suprasternal notch) is on the superior border of the manubrium. - Clavicular notches are to the sides of the jugular notch; these are where the clavicles (aka, collarbones), articulate with the sternum. - Costal notches articulate with the costal cartilages of the ribs ("costal" refers to the ribs). Rib Types • True ribs - Ribs 1-7; articulate with the sternum directly via their costal cartilages. • False ribs - Ribs 8-12; do not articulate directly with the sternum. - Ribs 11 and 12 are "floating ribs," do not articulate at all with the sternum. 1 / 2 Rib Features • Head - Articulates with the vertebral body; typically comprises two articular surfaces separated by a bony crest. • Neck - Extends from the head, and terminates at the tubercle. • Tubercle - Comprises an articular facet, which is where the rib articulates with the transverse process of the vertebra. • Shaft - Longest portion of the rib, extends from tubercle to rib end. • Angle - Bend in rib, just lateral to tubercle. Rib/vertebra articulation • Head and tubercle of rib articulate with body and thoracic process of vertebrae. Intercostal spaces • The spaces between the ribs • House muscles and neurovascular structures. - Intercostal neurovascular bundle, especially the intercostal artery, must be avoided during insertion of a chest tube. Powered by TCPDF (www.tcpdf.org) 2 / 2.