2. Benish Islam Lecturer / coordinator Surgical IPMS/KMU
Thoracic Wall
Benish Islam
Lecturer / coordinator Surgical IPMS/KMU

3. Structure Of thoracic Wall

4. Sternum Manubrium Body of sternum: Manibriusternal joint
Xipibhisternal joint
Sternal angle
Xiphoid process

5. Ribs Total 12 pair of ribs True ribs: upper 7 False: 8,9,10th ribs
Floating ribs: 11,12 ribs
Typical rib:Costal Groove,head,neck,
tubercle shaft,angle
Atypical rib: 1st rib

6. Thoracic outlet Opening at root of neck.
Oesophagus , trachea and blood vessels pass through it
Thoracic outlet

7. Endothoracic fascia Loose connective tissue
Separate parietal pleura from thoracic wall
Endothoracic fascia

8. Intercostal muscles (3 types)
External intercostal muscle:
Fibers directed downward and forward
From inferior border of rib above to superior border of rib below
Aponerosis: Ant.(external) intercostal membrane

9. 2. Internal intercostal muscle
Intermediate layer
Fibers directed downward and backward
From subcostal groove of rib above to upper border of rib below
Aponeurosis: post. (internal) intercostal membrane

10. 3.Innermost Intercostal muscle
Deepest layer
Corresponds to transversus abdominis in abdominal wall
Croses more than one intercostal space
Related to endothoracic fascia.
Blood vessels,nerves pass between intermediate and deepest layer.

11. Respiration mechanism:
Action
Supply
Inter costal nerves
Intercostal Arteries and veins:
Post. Intercostal arteries
Ant. intercostal veins

12. Diaphragm

13. Origin of diaphragm
Thin muscular tendinous septum,separate chest cavity above from abdominal cavity.
Sternl part:arises from post. Surface of xiphoid process
Costal Part:arise from deep surface of lower six ribs and costal cartilage.
Verterbral part:arises from vertebral column nd arcuate ligament.
Inserted into central tendon
Rt.dome: upper border of 5th rib
Lt. dome: lower border of5th rib

15. Diaphragm Muscle of Inspiration Muscle of Abdominal Straining
Nerve/Action
Function
Motor nerves:
rt,lt. phrenic nerves C3,4,5
Sensory nerves:
Phrenic nerve and lower six intercostal nerves
Action:On contraction, diaphragm pulls down central tendon and inc. vertical diameter of thorax.
Muscle of Inspiration
Muscle of Abdominal Straining
Weight lifting muscle
Thoracoabdominal pump

16. 3 major opening in diaphragm

18. Anterior view of thorax

19. Lines of orientation

20. Posterior chest wall

21. Surface Anatomy

22. Thank you