2. The chest is Region between the neck and abdomen.
Flattened in front & behind but rounded at the sides
Framework is called thoracic cage
2
3. Covered on the outside by skin and muscles attaching the
shoulder girdle to the trunk.
Lined with parietal pleural on the inside.
Walls
Anteriorly: Sternum & costal cartilages
Posteriorly: Thoracic part of vertebral column
Laterally: Ribs & intercostal spaces
Superiorly: Suprapleural membrane
Inferiorly: Diaphragm
3
4. A flat bone in the midline of the anterior chest wall
Divided into: manubrium sterni, body & xiphoid process
Relatively shorter and thinner in the female
Sternal angle (Angle of Louis): formed by articulation of the
manubrium with the body of the sternum
Joints:
◦ Manubriosternal – level of disc btw T4 & T5
◦ Xiphisternal – opposite the body of T9
◦ Manubrium articulates with clavicle and 1st rib
◦ Body of sternum articulates with 2nd to 7th costal cartilages.
4
5. Sternum and Marrow Biopsy
Since the sternum possesses red hematopoietic marrow throughout
life, it is a common site for marrow biopsy.
Under a local anesthetic, a wide-bore needle is introduced into the
marrow cavity through the anterior surface of the bone.
The sternum may also be split at operation to allow the surgeon to
gain easy access to the heart, great vessels, and thymus.
5
6. Consist of 12 pairs of bones that form the main part of the
thoracic cage
Structure:
Typical rib: long twisted flatbone and has head, neck, tubercule
angle & body (e.g 3rd to 9th ribs)
Atypical rib: are dissimilar (1st, 2nd, 10th, 11th & 12th ribs)
Classification:
True ribs: are ribs attached to their costal cartilages
False ribs: ribs 8th, 9th, 10th attached to costal cartilage of the 7th
rib.
Floating ribs: 11th & 12th, has no attachment anteriorly.
6
7. First Rib
Is the broadest and shortest of the true ribs.
Has a single articular facet on its head, which articulates with
the first thoracic vertebra.
Has a scalene tubercle for the insertion of the anterior scalene
muscle and two grooves for the subclavian artery and vein.
Second Rib
Has two articular facets on its head, which articulate with the
bodies of the first and second thoracic vertebrae.
Is about twice as long as the first rib.
7
8. Tenth Rib
Has a single articular facet on its head, which articulates with
the 10th thoracic vertebra.
Eleventh and Twelfth Ribs
Have a single articular facet on their heads.
Have no neck or tubercle.
8
10. Joints of the Sternum
Joints of the ribs
◦ Head
◦ Tubercules
◦ Costal cartilages
◦ Sternum
10
11. Sternoclavicular Joint
Saddle-type synovial joint with two separate synovial cavities
Provides the only bony attachment between the appendicular
and axial skeletons.
Sternocostal (Sternochondral) Joints
Articulates the sternum with the first seven cartilages.
Articulation of manubrium with first costal cartilage is
synchondrosis (cartilaginous)
Second to seventh costal cartilages form synovial plane joints
with the sternum.
11
12. Costochondral Joints
Articulation of ribs with their respective costal cartilages
Are synchondroses.
Manubriosternal Joint
Between manubrium and body of the sternum.
Is symphysis (secondary cartilaginous joint)
Xiphisternal Joint
Articulation between xiphoid process and body of the sternum
is synchondrosis
12
13. Costovertebral Joints
Synovial plane joints of heads of ribs with corresponding and
supraadjacent vertebral bodies.
Costotransverse Joint
Synovial plane joint of tubercle of rib with transverse process
of corresponding vertebra.
Interchondral Joints
Synovial plane joints between 6th and 10th costal cartilages of
ribs.
13
14. Boundaries
Anteriorly: Superior border
of manubrium sterni
Posteriorly: First thoracic
verterbra
Laterally: Medial border of
first ribs and their costal
cartilages
14
15. The Thoracic Outlet Syndrome
The brachial plexus of nerves (C5, 6, 7, and 8 and T1) and the
subclavian artery and vein are closely related to the upper
surface of the first rib and the clavicle as they enter the upper
limb.
It is here that the nerves or blood vessels may be compressed
between the bones. Most of the symptoms are caused by
pressure on the lower trunk of the plexus producing pain down
the medial side of the forearm and hand and wasting of the
small muscles of the hand. Pressure on the blood vessels may
compromise the circulation of the upper limb.
15
16. Muscle Origin Insertion Nerve Action
External
intercostals
Lower border of ribs Upper border of
rib below
Intercostal Elevate ribs in
inspiration
Internal
intercostals
Lower border of ribs Upper border of
rib below
Intercostal Depress ribs (costal
part);
elevate ribs
(interchondral
part)
Innermost
intercostals
Lower border of ribs Upper border of
rib below
Intercostal Elevate ribs
Transversus
thoracis
Posterior surface of
lower sternum and
xiphoid
Inner surface of
costal
cartilages 2–6
Intercostal Depresses ribs
Subcostalis Inner surface of lower
ribs near their angles
Upper borders of
ribs 2 or
3 below
Intercostal Elevates ribs
Levator
costarum
Transverse processes
of T7–T11
Subjacent ribs
between
tubercle and angle
Dorsal
primary
rami
of C8–T11
Elevates ribs
16
17. Spaces between the ribs
contaning:
◦ External intercostal muscle
◦ Internal intercostal muscle
◦ Innermost intercostal muscle
(*endothoracic fascia and
pleural)
◦ Neurovascular bundles:
Intercostal nerves and blood
vessels (VAN)
17
18. Structures penetrated by a needle when it passes from skin surface to
pleural cavity.
Depending on the site of penetration, the pectoral muscles will be
pierced in addition to the serratus anterior muscle.
18
20. Intercostal arteries and Veins
Each intercostal space contains a large single posterior intercostal artery
(PIA) and two small anterior intercostal arteries (AIA).
◦ PIAs of intercostal space 1 & 2 are branches from superior
intercostal artery, a branch of the costocervical trunk of the
subclavian artery.
◦ PIAs arteries of the lower nine spaces are branches of the
descending thoracic aorta.
◦ AIAs of the first six spaces are branches of the internal
thoracic artery, which arises from the first part of the
subclavian artery.
20
21. AIAs of lower spaces are
branches of the
musculophrenic artery, one of
the terminal branches of the
internal thoracic artery
Posterior intercostal veins
drain backward into the
azygos or hemiazygos veins,
and the anterior intercostal
veins drain forward into the
internal thoracic and
musculophrenic veins.
21
22. Intercostal nerves
Anterior rami of the first 11 thoracic spinal nerves.
Anterior ramus of the 12th thoracic nerve lies in the abdomen
and runs forward in the abdominal wall as the subcostal nerve.
Note: The first six nerves are distributed within their intercostal
spaces.
o 7th to 9th intercostal nerves leave the anterior ends of their
intercostal spaces by passing deep to the costal cartilages,
to enter the anterior abdominal wall.
o The 10th and 11th nerves, since the corresponding ribs are
floating, pass directly into the abdominal wall
22
24. First intercostal nerve
◦ Joined to the brachial plexus by a large branch that is equivalent to
the lateral cutaneous branch of typical intercostal nerves.
◦ The remainder of the first intercostal nerve is small, and there is no
anterior cutaneous branch.
Second intercostal nerve
◦ Is joined to the medial cutaneous nerve of the arm by a branch called
the intercostobrachial nerve
◦ supplies the skin of the armpit and the upper medial side of the arm.
In coronary artery disease, pain is referred along this nerve to the
medial side of the arm
24
25. A thin muscular and tendinous septum that separates the chest
cavity above from the abdominal cavity below. It is pierced by
the structures that pass between the chest and the abdomen
Parts of the origin
◦ Sternal part: from the posterior surface of the xiphoid
process.
◦ Costal part: from the deep surfaces of the lower six ribs and
their costal cartilages.
◦ Vertebral part: by vertical columns or crura and from the
arcuate ligaments.
25
27. Branch of the first part of subclavian artery supplying the anterior
wall of the body from the clavicle to the umbilicus.
Branches
2 anterior intercostal arteries (supply upper 6 ICS)
Perforating arteries
Pericardiacophrenic artery
Superior epigastric artery
Musculophrenic artery
27
29. Internal Thoracic Vein
Formed by the confluence of the superior epigastric and
musculophrenic veins,
Ascends on the medial side of the artery
Receives the upper six anterior intercostal and
pericardiacophrenic veins
Ends in the brachiocephalic vein.
Thoracoepigastric Vein
Is a venous connection between the lateral thoracic vein and the
superficial epigastric vein.
29
31. Sternal or Parasternal (Internal Thoracic) Nodes
Are placed along the internal thoracic artery.
Receive lymph from the medial portion of the breast, intercostal spaces,
diaphragm, and supraumbilical region of the abdominal wall.
Drain into the junction of the internal jugular and subclavian veins.
Intercostal Nodes
Lie near the heads of the ribs.
Receive lymph from the intercostal spaces and the pleura.
Drain into the cisterna chyli or the thoracic duct.
Phrenic Nodes
Lie on the thoracic surface of the diaphragm.
Receive lymph from the pericardium, diaphragm, and liver.
Drain into the sternal and posterior mediastinal nodes.
31
32. Suprasternal notch:
Is the superior margin of the manubrium sterni and is easily
felt between the prominent medial ends of the clavicles in the
midline. It lies opposite the lower border of the body of the
second thoracic vertebra.
The sternal angle (angle of Louis):
Angle made between the manubrium and body of the sternum.
It lies opposite the intervertebral disc between the fourth and
fifth thoracic vertebrae.
32
33. Xiphisternal Joint:
is the joint between the xiphoid process of the sternum and the
body of the sternum. It lies opposite the body of the ninth
thoracic vertebra.
The subcostal angle:
is situated at the inferior end of the sternum, between the
sternal attachments of the seventh costal cartilages.
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34. Costal Margin
Lower boundary of the thorax and is formed by the cartilages
of the 7th, 8th, 9th, and 10th ribs and the ends of the 11th and
12th cartilages.
Lowest part of the costal margin is formed by the 10th rib and
lies at the level of the third lumbar vertebra (L3).
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38. Anatomic and Physiologic Changes in the Thorax with Aging
The rib cage becomes more rigid and loses its elasticity as the result
of calcification and even ossification of the costal cartilages.
The stooped posture (kyphosis), so often seen in the old because of
degeneration of the intervertebral discs, decreases the chest capacity.
Disuse atrophy of the thoracic and abdominal muscles can result in
poor respiratory movements.
Degeneration of the elastic tissue in the lungs and bronchi results in
impairment of the movement of expiration.
These changes, when severe, diminish the efficiency of respiratory
movements and impair the ability of the individual to withstand
respiratory disease.
38
39. Read up the followings:
Surface markings of the lungs and heart
The pleural
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