Rib 4 (right) — true rib

Function

Overlies the horizontal fissure of the right lung and the dome of the diaphragm; moves with every breath and heart-adjacent pulsation.

Landmarks

• Costal groove
• Angle

Articulations (joints)

• T3–T4 vertebrae
• Sternum via fourth costal cartilage

Clinical relevance

ECG electrode V1 sits at the fourth intercostal space right of the sternum — placed by counting from this rib.