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Flashcards in L3 Thoracic Wall Deck (37):

Parts of Sternum

1. Manubrium
-manubriosternal joint/angle of Louis
2. Sternum Proper
3. Xiphi Sternum


Manubrium features

Articulates with 1st and 2nd ribs
has Jugular notch on top


Sternum Proper Features

Part of the sternum that the Majority of the ribs articulate with


Angle of Louis

Manubrio-sternal joint
slight angle = Convex (sticks out)
1. Start counting ribs from Rib 2
-e.g. for heart enlargement sitting b/w which ribs
2. -landmark for dehydrate/fluid over loaded patients
-pressure in jugular veins relative to angle of Louis



12 ribs
1-7 = True ribs
-articulate with spinal column -- lateral --attach to sternum via costal cartilages
8-10 = False ribs - non-direct attachment via costal cartilage of rib 7 and above
11-12 = Floating ribs - no anterior attachment


Which ribs are more likley to be broken?

true ribs along the middle portion, dont have alot of give and attach directly into the sternum
-Floating ribs have more movement so less likely to attachment


"Popped rib"

1. Can dislocate costal cartilage off sternum (sternal attachment)
-v painful
2. Rib break in boney portion


Vertebrae components

1. 7 Cervical vertebrae
2. 12 Thoracic Vertebrae
3. 5 Lumbar vertebrae
4. Sacrum
5. Coccyx



rigid box
ribs sternum and spinal column
everything has to stay in that box
move relative to each other within the box
-pressures change and top and bottom move (box cant change its sides)


Individual rib

Each rib articulates with its own vertebrae and the one above it
Head. Neck. Tubercle. Angle
Costal Groove=Neurovascular bundle is under and protected by ribs


Rib vs Nerve numericals

Rib V
T5 = nerve


Rib and Chest movement

Sternum lifts superiorly
Rib Bucket handle movement


Superior thoracic aperture

/Thoracic inlet
T1 Posterior + Rib1 Laterally + Manubrium Anteriorly
how great vessels and nerves enter and exit


Thoracic Cavity

Ribs Slop downwards as come off laterally
= posterior and anterior positioning different
=domes of pleura extends above first rib


Area of lung and pleural cavity is at risk

Dome of pleura extending above first risk
=unprotected region
+ big vessels and nerves entering here
=lung and pleural cavity at risk
Risk of pneumothorax/air in pleural cavity if inserting a central venous line


Inferior Thoracic aperture

Thoracic Outlet
bound by diaphragm + T12 vertebrae and rib + costal cartilages of false ribs



consists of 2x domes
-alot of abdominal contents protected by ribs
Major muscle of inspiration and expiration


Intercostal space

3x layers of intercostal muscles (External, Internal, Innermost I.M.)
-same fibre direction
Neurovascular b/w Internal and Innermost
-Sup--> Inf ( Vein --> Artery --> Nerve)
-Theoretically very well protected in costal groove in rib which sits above
-Another neurovascular bundle which are the co-lateral branches off main bundle, less important, not protected as lower down


Intercostal muscles

Stiffen chest wall
give diaphragm something to pull against
important if diaphragm has been paralysed but minor in normal breathing


Intercostal nerves

-from Anterior Rami of spinal nerves
-straight into intercostal space
-gives off branches which supply intercostal muscles
+ sensory branches which supply the skin


Thoracic Dermatomes

dermatomes in thoracic region are rel. tidy
-T4= nipple (male and children stbale. vary for women)
-T10= umbillicus
Slope in same direction as ribs


Thoracic arteries

Supply from two places in the intercostal space
1. Posterior directly off Aorta
2. Anterior off Internal Thoracic *


What are the final two branches off the internal thoracic arteries?

1. musculo-phrenic (final intercostal) (laterally)
2. Superior epigastic (inferiorly)
-meets inferior epigastric
-if problem with blood supply anastomoses can compensate for the other


Venous supply

Anterior= Internal Thoracic V --> Brachiochepahlic --> Herat
Posterior= Azygous system (Azygos vein, Accessory Hemiazygos V + Hemiazagos V) --> Heart


Nerve vs Blood supply

Nerve - Posterior in intercostal space
Blood- Anterior and Posterior



-Middle space
1. Superior Mediastinum (full of large arteries and veins)
2. Inferior Mediastinum
a) Anterior M (small thymus gland. important in children)
b) Middle M (heart)
c) Posterior M (oesophagus, aorta)



Mammary gland
-a collection of secretory lobules, fat and lactiferous ducts
-sits anterior to muscles of thoracic wall (Pec maj, Serratus Ant)
-Retromammary space/facia
-arterial supply and venous drainage


Retromammary space

Retromammary space/fascia
what breast sits on
moves relatively freely
-when breast tumour, once invades into this space, it glues breast to chest
-look for "puckering"/fixed adherence of breast to chest wall as tumour has invaded that space
-ask woman to raise arms above head, and see how freely breast moves rel. to other side
-further investigate


Arterial supply of breast

from three different places
1. Medially: Internal Thoracic Branches (which runs down lateral to sternum and branches into Intercostal space)
2. Laterally: Axillary artery, (Lateral Thoracic + Thoracoaccromial artery)
3. Directly: Intercostal arteries - pierces through intercostal space to skin as well


Mammary tissue of breast

tissue extends into axillary process/tail
-examine (a lot of space and fat in axilla) tumour and growth can hide better


Breast Lymphatic Drainage

1. 75% lymphatic drainage goes Laterally (into axillary nodes (Lateral and Pectoral))
2. Most of remainder goes medially into Parasternal nodes (up and down sternum)(can cross sternum into other side-breast cancer metastasised to other side)
3. abdominal nodes


Sentinel Node Biopsy

Dye prior to surgery into the tumour
see where tumour has metastasized too and which direction
Nodes containing tumour will take up the dye, shows where tumour is draining too
Target surgery (dont leave behind but dont take out too much)


Breast nerve supply

T4-6 Intercostal nerves
-overlies these ribs


Pectus Excavatum

Chest wall deformity
-Deformity of sternum and Costal Cartilages
-sunken in
-breathing problems as smaller thoracic box size
-assoc. with congenital abnormlaities re heart and lung problems


Pectus Carinatum

Pigeon chest
sternum protrudes
-assymetrical (often on one side)


Spinal Curvatures

Primary Curvatures: Thoracic + Sacral/Coccygeal
Secondary Curvatures: Cervical + Lumbar


Spinal Deformities

Kyphosis - thoracic (can go into lumbar)
Lordosis - lumbar
Extreme deformities of spinal column: Neuromuscular condition with very abnormal musculature and tone
Scoliosis- curve in coronal plane + rotational deformity(twisted) (alot of chest infections as small collapsed box size + 90 degree pelvis as cant sit correctly as pelvis cant be level (in wheelchair))