1. The Thoracic Wall:
Bony Thoracic Cage

2. Thoracic Wall
• Structure:
skin  fascia  muscle  bone
blood vessels & nerves
• Functions:
1. protection of thoracic
viscera
2. provides the mechanical
function of breathing

3. Thoracic Cage
The bony part of thoracic wall
- 12 pairs of ribs & CC
- 12 thoracic vertebrae
- Sternum

4. Ribs
- Flat curved bones with high
resilience
- Form most of the thoracic cage
-3 types:
1. True (1 st – 7 th )
2. False (8 th – 10 th )
3. Floating (11 th & 12 th )

5. Features of Typical Ribs
1. Head: wedge-shaped with 2 articular facets
2. Neck: connects the head with the body
3. Tubercle: articular &
non-articular parts
4. Shaft (Body): angle &
costal groove

6. Typical Ribs
3 rd – 9 th ribs are considered
typical
1. Articular facets
2. Crest of Head
3. Neck
4+5. Tubercle
6. Angle
7. Costal groove
8. shaft

7. Atypical Ribs
• 1st rib
Flat, scalene tubercle & grooves for subclavian v.
• 2nd rib
rough tuberosity for serratus anterior m.
• 10th rib
one facet on the head
• 11th & 12th
one facet on the head & no neck or tubercle

8. 1st Rib
1. Flat rib
2. Scalene Tubercle
3. Grooves for
subclavian vessels
4. One Facet on the
head

9. Clinical: Cervical Rib
• Extra rib arise from C7 vertebra
• Present in ∼1% of people
• Complications:
Causes pressure on nerves & arteries supplying the
upper limb
Tingling & numbness  Partial paralysis
ischemic muscle pain (due to?)

10. Cervical Rib

11. Rib Fractures
• Common chest injuries (middle ribs, 5-10)
• Mostly in weakest part (the angle)
• Present as a sever localized pain
• Complications: inj. to underlying structures
pneumothorax (air in pleural cavity)

12. Structure of Vertebrae
Body
Vertebral arch
(P & L)
7 processes

13. Distinguishing Features of Thoracic
Vertebrae

14. Sternum
( G, Sternon: chest bone )
Flat, vertically elongated bone
that forms the middle anterior
part of the thoracic cage
3 parts:
Manubrium
Body
Xiphoid process

15. Manubrium
Shaped
(L, Handle)
* Several notches:
Jugular  Clavicular 
Costal
* Manubriosternal Joint:
2 o fibrocartilaginous
Sternal angle

16. Sternal Angle
Angle of louis
Manubriosternal
joint
Easily palpated
Opposite to T4-T5
disc
2nd costal cartilage:
Counting the ribs & intercostal spaces

17. Body: T5 – T9, costal notches 3 rd – 7 th
Xiphoid process: T10, hyaline cartilage 
ossified

18. Openings of Thoracic Wall
Boundaries of superior
thoracic opening:
T1,
1 st rib,
manubrium
Boundaries of inferior
thoracic opening:
T12,
11 th & 12 th ribs,
7-10 CC,
xiphisternal joint

19. Thoracic Outlet Syndrome
• On the superior thoracic opening (anatomical inlet)
• Compression of subclavian art. between the clavicle & 1st rib
(Costoclavicular syndrome)
• Pale color & coldness on the skin of upper limb
• Diminished radial pulse

20. Joints of Thoracic Cage
Posteriorly:
1. Intervertebral joints 1
(2 o cartilaginous)
2
2. Costovertebral joints
(synovial plane)
3. Costotransverse joints
3
(synovial plane)

21. Joints of Thoracic Cage
Anteriorly:
1. Costochondral joints
(1 o cartilaginous)
2. Sternocostal joints
(synovial plane,
except 1 st CC )
3. Manubriosternal joint
(2 o cartilaginous)
4. Xiphisternal joint
(1 o cartilaginous)

22. Intercostal Muscles
3 layers of m. that cover intercostal spaces
From outside to inside:
1. External intercostal m.:
runs downward toward sternum (your ant. pockets)
replaced anteriorly by membrane
2. Internal intercostal m.:
runs downward toward VC (your post. pockets)
replaced posteriorly by membrane

23. 3. Innermost intercostal & Transversus
Thoracic
IIm:
on lateral sides only
TTm:
4-5 slips of muscles
From post. surface of sternum
To 2 nd -6 th costal cartilages
Bld. Vessels & nerves run between:
Internal & innermost IMs