L3 Thoracic Wall Flashcards
Parts of Sternum
- Manubrium
- manubriosternal joint/angle of Louis - Sternum Proper
- 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
Ribs
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”
- Can dislocate costal cartilage off sternum (sternal attachment)
- v painful - Rib break in boney portion
Vertebrae components
- 7 Cervical vertebrae
- 12 Thoracic Vertebrae
- 5 Lumbar vertebrae
- Sacrum
- Coccyx
Thorax
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
TV
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
Diaphragm
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
- Posterior directly off Aorta
- Anterior off Internal Thoracic *
What are the final two branches off the internal thoracic arteries?
- musculo-phrenic (final intercostal) (laterally)
- Superior epigastic (inferiorly)
- meets inferior epigastric
- if problem with blood supply anastomoses can compensate for the other
Venous supply
Drainage:
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
Mediastinum
- 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)
Breast
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
- Medially: Internal Thoracic Branches (which runs down lateral to sternum and branches into Intercostal space)
- Laterally: Axillary artery, (Lateral Thoracic + Thoracoaccromial artery)
- 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
- 75% lymphatic drainage goes Laterally (into axillary nodes (Lateral and Pectoral))
- Most of remainder goes medially into Parasternal nodes (up and down sternum)(can cross sternum into other side-breast cancer metastasised to other side)
- 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))
