ManubriumThe top piece of the sternum, roughly a trapezoid. The collarbones and the cartilages of the first ribs join it, and part of the second.
Body of the sternumThe longest of the three pieces. Facets down each edge take the cartilages of ribs 3 to 6, with half-facets for ribs 2 and 7 at its ends.
Xiphoid processThe lowest and smallest piece. It is mostly cartilage in a young person and turns fully to bone late in life.
Jugular notch (suprasternal notch)The dip in the top edge of the manubrium. It shows under the skin at the base of the neck, between the two collarbones.
Clavicular notchOne on each side of the jugular notch. The inner end of a collarbone sits in it, and the two make the sternoclavicular joint.
Sternal angleThe joint between the manubrium and the body. It can be felt as a ridge across the bone, and the cartilage of the second rib meets the sternum here, so ribs are counted from it.
Facets for the costal cartilagesSmall hollows lined with cartilage along each edge of the sternum. The cartilage of one of the first seven ribs fits into each.
The rib cage 8
True ribs (1 to 7)The first seven pairs. Each reaches the sternum through a cartilage of its own.
False ribs (8 to 10)Pairs 8, 9 and 10. The cartilage of each joins the cartilage of the rib above and not the sternum.
Floating ribs (11 and 12)The last two pairs. They are short, join only the backbone and end free in the muscle of the body wall.
Costal cartilageA bar of hyaline cartilage that carries a rib to the sternum. The cartilages make the chest wall springy.
Costal marginThe lower front edge of the rib cage. The joined cartilages of ribs 7 to 10 make it.
Intercostal spaceThe gap between one rib and the next. There are eleven on each side, filled by the intercostal muscles.
Thoracic vertebrae (12)The twelve vertebrae of the chest. Every rib joins them at the back.
Infrasternal angle (subcostal angle)The angle the two costal margins make where they meet. The xiphoid process points down into its top.
One rib 6
Head of the ribThe end that meets the backbone. It is wedge shaped with two facets: one for its own vertebra and one for the vertebra above.
Neck of the ribThe short, narrow part that joins the head to the body.
Tubercle of the ribA bump where neck and body meet. Its facet rests on the transverse process of the vertebra.
Angle of the ribJust past the tubercle the rib bends and turns toward the front. A deep muscle of the back attaches here.
Body of the rib (shaft)The long part of the rib: thin, flat and curved. Its front end joins the costal cartilage.
Costal grooveA groove along the inner face of the body, low down. The intercostal vein, artery and nerve run in it.
How this list was compiled: Every name and detail line was checked on 2026-09-30 against Gray, Anatomy of the Human Body, 20th edition, 1918 (public domain), the sections on the sternum, the ribs, the costal cartilages and the thorax, https://archive.org/details/anatomyofhumanbo00grayrich; TeachMeAnatomy, The Sternum, https://teachmeanatomy.info/thorax/bones/sternum/, and The Ribs, https://teachmeanatomy.info/thorax/bones/ribcage/; and Kenhub, Sternum, Ribs and Thoracic cage, https://www.kenhub.com/en/library/anatomy/thoracic-cage. The wording is in our own words. Licence: own work
The drawing: Drawn for this site on 2026-09-30 from plain geometry; nothing traced. Licence: own work
How it works
Three drawings: the sternum from the front, the whole rib cage, and one rib on its own. Every part is named first. Then the quiz asks you to label the structures of the thoracic cage yourself.
Read the full guide
The sternum, top to bottom
Three pieces: the manubrium, the body and the xiphoid process. The jugular notch is the dip in the top edge, with a clavicular notch for a collarbone on each side of it. The ridge where the manubrium meets the body is the sternal angle; the second rib joins there.
The cage and one rib
Ribs 1 to 7 reach the sternum by their own cartilages, 8 to 10 join the cartilage above, and 11 and 12 end free. On a single rib, start at the backbone: head, neck, tubercle, then the bend called the angle and the long body with the costal groove inside.
To count ribs, find the sternal angle first: the rib beside it is the second.
The false ribs never touch the sternum; follow a cartilage upward and it runs into the one above.
Questions and answers
What are the three parts of the sternum?
The manubrium at the top, the body in the middle and the xiphoid process at the bottom. In children cartilage joins the three; it turns to bone in adults, and the xiphoid process is the last to harden.
What is the difference between true, false and floating ribs?
True ribs, pairs 1 to 7, each reach the sternum through their own cartilage. False ribs, pairs 8 to 10, join the cartilage of the rib above. Floating ribs, pairs 11 and 12, join only the backbone.
Is there a thoracic cage unlabeled sheet to print?
Yes. The blank sheet shows all three drawings with numbered rings and a line for each name: 1 to 7 on the sternum, 8 to 15 on the rib cage and 16 to 21 on the single rib.
Where is the sternal angle?
It is the joint between the manubrium and the body of the sternum, a short way below the jugular notch. It can be felt as a ridge across the bone, level with the cartilage of the second rib.