Thoracic Wall

Question 1

Division of the ribs

Answer 1

True ribs (1-7): Articulate with the manubrium and sternum via costal cartilages
False Ribs (8-10): attach to above costal cartilages.
Floating Ribs (11-12): don't attach, free floating

Question 2

Which ribs are most likely to be damaged and why?

Answer 2

True ribs (1-7) as they strongly articulate with the sternum

Question 3

What is the joint called at rib 2? What’s its purpose

Answer 3

‘Manubriosternal joint’ or angle of Louis

• Landmark to find jugular vein (important around pressure and fluid retention)
• Where you start counting from.
• The slight angle between manubrium and sternum

Question 4

Whats at the top of the manubrium and bottom of the sternum?

Answer 4

top: jugular notch
Bottom: xiphis sternum

Question 5

Parts of each rib

Answer 5

Head, neck, angle (costal groove lies), costal cartilage

Question 6

Whats the purpose of the costal groove?

Answer 6

Where the NV bundle sits and is protected.

Question 7

Boundries of the THoracic inlet

Answer 7

T1 posterior
Rib 1 laterally
manubrium anterior

Question 8

Boundries of the Thoracic Outlet

Answer 8

T12, Rib 12, cc of false ribs, diaphragm

Question 9

The diaphragm is made of ___ domes, and there purpose is to

Answer 9

The diaphragm is made of 2 domes, and there purpose is to go high up in the thorax and protect things like spleen and liver

Question 10

The ribs are angled

Answer 10

Downwards. This means the dome of pleura is higher then the first rib, its unprotected and at risk of damage

Question 11

2x movements of the rib cage

Answer 11

ANterior/Superior movement of the manubrium and upper ribs

bucket handle movement of the ribs

Question 12

What are the Intercostal muscle layers. Purpose

Answer 12

Similar to the abdominal

• External intercostal muscle
• Internal intercostal muscle
• innermost intercostal muscle (same fibre direction as internal)

These stiffen the chest wall and give the diaphragm something to pull on. Has a minor role in breathing

Question 13

The NV bundle runs between which muscle layers

Answer 13

Inner IC and innermost IC

Question 14

NV bundle from superior to inferior. What else runs allongside NV bundle

Answer 14

VAN

collateral bundle runs above rib, smaller and not protected

Question 15

Nerves in NV bundle, and what are their branches

Answer 15

Intercostal nerves from anterior rami.
Give off branches that supply IC muscles and skin

-therefore dermatomes are mapped like lines.

Question 16

Nipple line is at

Answer 16

T4 dermatome

Question 17

Two sources of arterial supply

Answer 17

Intercostal arteries
Posterior: directly off aorta
Anterior: off internal thoracic

Question 18

Draw arterial branches

Answer 18

…

Question 19

Two sources of venous supply

Answer 19

Matches arterial supply
Intercostal Veins
Posterior: Azygos system (azygos vein, accessory hemiazygos vein, hemiazygos vein
Anterior: internal Thoracic vein

Question 20

Divisions of the mediastinum

Answer 20

Mediastinum = middle space/ cavity
Superior and inferior
Inferior has:
-Anterior MS (small thymus gland)
-Middle MS (heart)
-Posterior MS (oesophagus, aorta)

Question 21

Breast sit on. Clinical relevance

Answer 21

Thoracic wall muscle (s.anterior and pec major) and the ‘retromammary space’. This usually allows breasts to move relatively freely, but when you get a breast tumor, if it invades this space, the breast cannot move and will look fixed (GOOD INDICATION)

Question 22

Lymphatic Drainage of Breasts

Answer 22

75% = Lateral and pectoral axillary nodes. Drain laterally to these.

rest = mostly Parasternal Nodes (these go through the midline, so cancer can travel)

Question 23

Breast Arterial supply

Answer 23

Medially: internal thoracic artery branches
Laterally: Axillary artery branches
Directly: Intercostal arteries

Question 24

Breast Nerve supply

Answer 24

Intercostal nerves T4, T5, T6

Question 25

Centitil node Biopsy

Answer 25

Inject dye into tumor to see where its metastisized to.

If lymphnodes take up dye = cancer

Question 26

Axillary Tail

Answer 26

Breast tissue extends laterally, lots of fat and tissue so its easy for a tumor to hide

Question 27

Chest sunken in

Answer 27

Pectis Excavaosum

-breathing issues

Question 28

Chest protruding out

Answer 28

Pectis Carinatum. Usually asymptomatic

Question 29

Exaggerated curvatures

Answer 29

Lordosis and Kyphosis and scoliosis