Origins
Sternum entered English from Latin, which borrowed it from Greek sternon, meaning chest or breastbone. The Greek word likely connects to the Proto-Indo-European root *ster-, meaning to spread out or lay flat — a reference to the broad, flat surface of the human chest. This same root produced Latin sternere (to spread, to lay down), which gave English a string of related words: strew, stratum, strata, prostrate, and street (originally a paved, spread-out road).
The sternum is a flat, dagger-shaped bone at the center of the anterior chest wall. It consists of three parts: the manubrium (the handle-shaped upper section), the body or gladiolus (the blade), and the xiphoid process (the small pointed tip at the bottom). The anatomical terminology itself is layered with metaphor — manubrium means handle in Latin, gladiolus means small sword, and xiphoid comes from Greek xiphos (sword).
Ancient Greek physicians including Hippocrates and Galen described the sternon in their anatomical writings, though their understanding of its function differed from modern medicine. They recognized it as a protective structure for the heart and lungs but attributed various humoral properties to the chest region.
Scientific Usage
The sternum serves several critical functions. It anchors the rib cage, protects the heart and major blood vessels, and provides attachment points for muscles of the chest and upper abdomen. In medical emergencies, the sternum is the target for CPR compressions. It also contains red bone marrow throughout life, making sternal aspiration a diagnostic procedure in hematology.
Forensic scientists use the sternum to estimate age at death. The three sections fuse gradually — the body and manubrium typically join around age 25, while the xiphoid may remain partly cartilaginous into old age. The degree of fusion provides useful clues when other aging indicators are unavailable.