L3 Thoracic Wall

Question 1

Parts of Sternum

Answer 1

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

Question 2

Manubrium features

Answer 2

Articulates with 1st and 2nd ribs

has Jugular notch on top

Question 3

Sternum Proper Features

Answer 3

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

Question 4

Angle of Louis

Answer 4

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

Question 5

Ribs

Answer 5

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

Question 6

Which ribs are more likley to be broken?

Answer 6

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

Question 7

“Popped rib”

Answer 7

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

Question 8

Vertebrae components

Answer 8

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

Question 9

Thorax

Answer 9

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)

Question 10

Individual rib

Answer 10

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

Question 11

Rib vs Nerve numericals

Answer 11

Rib V
TV
T5 = nerve

Question 12

Rib and Chest movement

Answer 12

Sternum lifts superiorly

Rib Bucket handle movement

Question 13

Superior thoracic aperture

Answer 13

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

Question 14

Thoracic Cavity

Answer 14

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

Question 15

Area of lung and pleural cavity is at risk

Answer 15

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

Question 16

Inferior Thoracic aperture

Answer 16

Thoracic Outlet

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

Question 17

Diaphragm

Answer 17

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

Question 18

Intercostal space

Answer 18

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

Question 19

Intercostal muscles

Answer 19

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

Question 20

Intercostal nerves

Answer 20

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

Question 21

Thoracic Dermatomes

Answer 21

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

Question 22

Thoracic arteries

Answer 22

Supply from two places in the intercostal space

1. Posterior directly off Aorta
2. Anterior off Internal Thoracic *

Question 23

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

Answer 23

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

Question 24

Venous supply

Answer 24

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

Question 25

Nerve vs Blood supply

Answer 25

Nerve - Posterior in intercostal space | Blood- Anterior and Posterior

Question 26

Mediastinum

Answer 26

- 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)

Question 27

Breast

Answer 27

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

Question 28

Retromammary space

Answer 28

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

Question 29

Arterial supply of breast

Answer 29

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

Question 30

Mammary tissue of breast

Answer 30

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

Question 31

Breast Lymphatic Drainage

Answer 31

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

Question 32

Sentinel Node Biopsy

Answer 32

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)

Question 33

Breast nerve supply

Answer 33

T4-6 Intercostal nerves | -overlies these ribs

Question 34

Pectus Excavatum

Answer 34

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

Question 35

Pectus Carinatum

Answer 35

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

Question 36

Spinal Curvatures

Answer 36

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

Question 37

Spinal Deformities

Answer 37

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))