The thoracic wall is comprised of skin, fascia, muscles and bones. It protects the thoracic viscera and enables breathing movements. The bony thoracic cage consists of 12 pairs of ribs connected to 12 thoracic vertebrae and the sternum. There are three types of ribs: true ribs that connect to the sternum, false ribs that connect to ribs above, and floating ribs that do not connect to other bones. The thoracic vertebrae are distinguished by demifacets on the vertebral bodies. The sternum consists of the manubrium, body, and xiphoid process. Openings in the thoracic wall include the superior inlet bounded by the clavicle, first

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 wallThe bony part of thoracic wall
- 12 pairs of ribs & CC- 12 pairs of ribs & CC
- 12 thoracic vertebrae- 12 thoracic vertebrae
- Sternum- Sternum

4. Ribs
- Flat curved bones with high- Flat curved bones with high
resilienceresilience
- Form most of the thoracic cage- Form most of the thoracic cage
-3 types:3 types:
1. True (11. True (1stst
– 7– 7thth
))
2. False (82. False (8thth
– 10– 10thth
))
3. Floating (113. Floating (11thth
& 12& 12thth
))

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
33rdrd
– 9– 9thth
ribs are consideredribs are considered
typicaltypical
1.1. Articular facetsArticular facets
2.2. Crest of HeadCrest of Head
3.3. NeckNeck
4+5. Tubercle4+5. Tubercle
6. Angle6. Angle
7. Costal groove7. Costal groove
8. shaft8. 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
1.1. Flat ribFlat rib
2. Scalene Tubercle2. Scalene Tubercle
3. Grooves for3. Grooves for
subclavian vesselssubclavian vessels
4. One Facet on the4. One Facet on the
headhead

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

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
BodyBody
Vertebral archVertebral arch
(P & L)(P & L)
7 processes7 processes

13. Distinguishing Features of Thoracic
Vertebrae

14. Sternum
((G, Sternon: chest boneG, Sternon: chest bone ))
Flat, vertically elongated boneFlat, vertically elongated bone
that forms the middle anteriorthat forms the middle anterior
part of the thoracic cagepart of the thoracic cage
3 parts:3 parts:
ManubriumManubrium
BodyBody
Xiphoid processXiphoid process

15. Manubrium
ShapedShaped
(L, Handle)(L, Handle)
* Several notches:* Several notches:
JugularJugular  ClavicularClavicular 
CostalCostal
* Manubriosternal Joint:* Manubriosternal Joint:
22oo
fibrocartilaginousfibrocartilaginous
Sternal angleSternal angle

16. Sternal Angle
Angle of louisAngle of louis
ManubriosternalManubriosternal
jointjoint
Easily palpatedEasily palpated
Opposite to T4-T5Opposite to T4-T5
discdisc
2nd costal cartilage:2nd costal cartilage:
Counting the ribs & intercostal spacesCounting the ribs & intercostal spaces

17. Body:Body: T5 – T9, costal notches 3T5 – T9, costal notches 3rdrd
– 7– 7thth
Xiphoid process:Xiphoid process: T10, hyaline cartilageT10, hyaline cartilage 
ossifiedossified

18. Openings of Thoracic Wall
•Boundaries of superior thoracicBoundaries of superior thoracic
opening:opening:
•Post: T1,Post: T1,
•On each side: 1On each side: 1stst
rib,rib,
• Ant: manubriumAnt: manubrium
•Contents of InletContents of Inlet
• Viscera : Tachea, oesophagusViscera : Tachea, oesophagus
• Large Vessels: Brachiocphalic arteryLarge Vessels: Brachiocphalic artery
Lf common caotid artLf common caotid art
•Small Vessels:Small Vessels:
Rt&Lt Int thorasic artRt&Lt Int thorasic art
Rt&Lt superior Intercosatal artRt&Lt superior Intercosatal art
• Nerves& muslesNerves& musles

19. Boundaries of inferiorBoundaries of inferior
thoracic openingthoracic opening /outlet/outlet::
• Posteriorly: T12,Posteriorly: T12,
• On each side: 7-10 CC,On each side: 7-10 CC,
• Anteriorly: xiphisternal jointAnteriorly: xiphisternal joint

20. 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

21. Joints of Thoracic Cage
Posteriorly:Posteriorly:
1.1. Intervertebral jointsIntervertebral joints
(2(2oo
cartilaginous)cartilaginous)
2. Costovertebral joints2. Costovertebral joints
(synovial plane)(synovial plane)
3. Costotransverse joints3. Costotransverse joints
(synovial plane)(synovial plane)
1
2
3

22. Joints of Thoracic Cage
Anteriorly:Anteriorly:
1.1. Costochondral jointsCostochondral joints
(1(1oo
cartilaginous)cartilaginous)
2. Sternocostal joints2. Sternocostal joints
(synovial plane,(synovial plane,
except 1except 1stst
CCCC))
3. Manubriosternal joint3. Manubriosternal joint
(2(2oo
cartilaginous)cartilaginous)
4. Xiphisternal joint4. Xiphisternal joint
(1(1oo
cartilaginous)cartilaginous)

23. Intercostal Muscles
3 layers3 layers of m. that cover intercostal spacesof m. that cover intercostal spaces
From outside to inside:From outside to inside:
1. External intercostal m.:1. External intercostal m.:
runs downward toward sternum (runs downward toward sternum (your ant. pocketsyour ant. pockets))
replacedreplaced anteriorlyanteriorly by membraneby membrane
2. Internal intercostal m.:2. Internal intercostal m.:
runs downward toward VC (runs downward toward VC (your post. pocketsyour post. pockets))
replacedreplaced posteriorlyposteriorly by membraneby membrane

24. 3. Innermost intercostal & Transversus3. Innermost intercostal & Transversus
ThoracicThoracic
IIm:IIm:
on lateral sides onlyon lateral sides only
TTm:TTm:
4-5 slips of muscles4-5 slips of muscles
From post. surface of sternumFrom post. surface of sternum
To 2To 2ndnd
-6-6thth
costal cartilagescostal cartilages
Bld. Vessels & nerves run between:
Internal & innermost IMs