1. THORACIC CAGE and WALL
SURFACE LANDMARKS

2. Lines of Orientation Refer: Midsternal line Midclavicular line
Text: pp (91)
Syllabus: p 44
Midsternal line
Midclavicular line
Anterior axillary line
Posterior axillary line

3. Lines of Orientation
Midaxillary line
Scapular line

4. Surface Landmarks Jugular notch Sternal angle: Apex heart beat:
Marks rib 2
Lies at level of T4-5 IV disc
Apex heart beat:
Left IC space 5; midclavicular line
Aortic valve:
Right IC space 2

5. Surface Landmarks Infrasternal angle: Important in CPR.
Depression between is the infrasternal fossa.
Xiphisternal joint within the fossa is at the level of the body of T9.

6. Surface Landmarks Pulmonary valve Tricuspid valve Bicuspid valve
Left IC space 2
Tricuspid valve
Right IC space 5
Bicuspid valve
Left IC space 5
Bifurcation of trachea
Vertebral level T4-5

7. Surface Landmarks Posterior thorax: scapula: Costal margin:
Scapular spine is at level of 3rd rib and T2 vertebra.
Inferior scapular angle is at the level of the 7th rib, the spine of T7 or the body of T9.
Costal margin:
Superior part is marked by the 7th cartilage.
Inferior part is marked by the 10th cartilage

8. Cutaneous innervation
Clavicular and scapular regions:
C3-4
Region of xiphoid process: T6
Anterior thorax:
T1-T6
Upper extremity:
C5-T1
Lower thorax and anterior abdomen:
T7-T12

9. OSTEOLOGY OF THE THORACIC CAGE

10. Structure of the Thoracic Cage
Twelve thoracic vertebrae
Twelve pairs of ribs and their costal cartilages
Sternum
Intercostal muscles

11. Superior Boundary (outlet)
First thoracic vertebra
First pair of ribs and costal cartilages
Manubrium
Refer to Fig. 14, p. 53 in syllabus

12. Inferior Boundary (outlet)
Twelfth thoracic vertebra
Twelfth pair of ribs and costal cartilages
Xiphisternal joint
Refer to Fig. 14, p. 53 in syllabus

13. Bones of the Thoracic Cage
Manubrium
Body of sternum:
Four sternebrae
Xiphoid process
Manubriosternal joint:
Symphysis
Synostosis after age 30 in some

14. Ribs Costa: Vertebrosternal ribs: Vertebrochondral ribs:
= Rib bone + its cartilage
Vertebrosternal ribs:
1-7
Vertebrochondral ribs:
8-10
Vertebral ribs (floating):
11-12

15. Typical Rib
Head:
Two articular facets for articulation with costal demifacets on adjacent thoracic vertebrae.
Bony crest between facets for attachment to intervertebral disc.

16. Typical Rib Neck: Tubercle: Narrow portion between head and tubercle.
Articulates with transverse process of vertebra with same number.

17. Typical Rib
Shaft
Sternal extremity
Angle

18. Typical Rib Costal groove: Costal cartilage
Contains superior to inferior:
Intercostal vein
Intercostal artery
Intercostal nerve
Costal cartilage

19. First Rib Flattened in a horizontal (transverse) plane.
Scalene tubercle:
For insertion of scalenus anterior muscle.
Shallow groove for subclavian vein:
Anterior to tubercle
Shallow groove for subclavian artery:
Posterior to tubercle

20. Thoracic Vertebra Heart-shaped centrum (body)
Centrum notched on left side for descending aorta
Intervertebral discs = ¼ of total length of thoracic vertebral region
Superior and inferior costal demifacets:
(on typical vertebrae (T2 – T9)

21. Thoracic Vertebra Vertebra prominens (C7):
First spinous process to be palpated.
T1 spinous process most prominent

22. Atypical Thoracic Vertebra
Superior costal facet (not a demifacet).
T10:
One pair of costal facets located partly on body and partly on pedicle.
T11 and T12:
One pair of costal facets located on pedicles.

23. Typical Rib Articulation
Head articulates with demifacets of its own number vertebra and the vertebra above as well as the intervertebral disc between:
Tubercle articulates with transverse process of same number vertebra.