anatomy of sternum, different part of sternum, their border and surfaces. the attachments of sternum and the relations.

1. STERNUM
DR SANA YASEEN
ANATOMY DEPARTMENT

2. INTRODUCTION
 Type of bone : flat bone
 Shape: short sword like
 Length: 17 cm long
 Longer in males than in female
 Parts :
 upper part, : manubrium
 middle part : body
 and lower part : xiphoid process or xiphisternum

5. MANUBRIUM
 Quardangular in shape
 Thickest and the strongest part of
sternum
 Has
 2 surface : anterior and posterior
 Four borders : superior , inferior, 2 lateral

6.  Anterior suurface : convex
 Posterior surface: concave (anterior boundary of superior mediastinum)
 Superior border: thick, round and concave. (marked by supra sternal notch,
jugular notch / interclavicular notch in median line and clavicular notch laterally)
 Inferior border: sec. Cartilagineous joint with body of sternum
 Lateral border: forms primary cartilaginous joint with the first costal cartilage.
 STERNAL ANGLE OF LUOIS: the manubrium makes a slight angle with the
body of sternum, convex forward , called angle of luois. Lies 5cm below the
supra sternal notch. Is formed by the articulation of manubrium with the boy of
sternum.

7. SIGNIFICANCE OF STERNAL ANGLE OF LUOIS
 Horizontal plane drawn at this level separate superior
mediastinum from inferior mediastinum
 Rib - 2nd rib
 Aorta: ending of ascending aorta, begning of arch of
aorta, ending of arch of aorta, begning of descending
aorta
 Trachea: bifurcation
 Pulmonary trunck: bifurcation
 Azygous vein drains into SV
 Thoracic duct crosses from right to left
 Upper border of heart is located at this level

9. BODY OF STERNUM
 Longer, narrow and thinner
 Widest to its end
 Has
 2 surfaces: anterior an posterior
 2 lateral borders
 2 ends: upper and lower ends

11. XIPHOID PROCESS
 Is the smallest part
 Is cartiligenuous later in
adults ossify
 Lies in the floor of epigastric
fossa

12. ATTACHMENTS

14. CLINICALS

15. FUNNEL CHEST
 Pectus excavatum is when
the ribs and the breastbone
(sternum) grow inward and
form a dent in the chest.
 This gives the chest a
concave (caved-in)
appearance, which is why the
condition is also called funnel
chest or sunken chest.
 Sometimes, the lower ribs
might flare out.

16. PIGEON CHEST
 Pectus carinatum (PC, or pigeon
chest) is a chest wall deformity
where there is overgrowth of the
cartilage between the ribs and
the sternum (breastbone),
causing the middle of the chest
to stick out
 Forward projection of the
sternum and flattening of chest
wall laterally