Lecture 1: Thoracic wall Flashcards
What four components make up the bony rim of the superior thoracic aperature?
T1 body Rib 1 Manubrium Jugular notch?
What two things do structures passing between the thorax and upper limb pass over?
Grooves for subclavian vein and artery, separated by scalene tubercle.
What structure attaches to the margins of and close off the inferior thoracic aperture?
Diaphragm
What are the medial and lateral branches that supply the breast tissue?
- Medial mammary branches from INTERNAL thoracic art. - Lateral mammary branches from lateral thoracic art.
What nerve innervates the nipple specifically?
Fourth thoracic intercostal nerve i.e T4 level
What are the primary and secondary lymphatic drainage sites for the breast?
Axillary lymph nodes (75%) Parasternal lymph nodes (rest)
What are the features of a typical rib?
- Head (3 articulations) - Tubercle (articulation and costotransverse lig) - Costal angle - Costal groove (int. inf. protects intercostal vessels +nerves)
What features are found on rib one?
The SCALENE tubercle separates the two grooves on the surface of rib one. Anterior groove for: Subclavian vein Post groove for: Subclavian artery
What ribs are typical?
3-9
Which structure divides the joint with the head of rib into two seperate joint cavaties?
Intra-articular ligment from crest to vertebral body
What ribs are typical?
3-9
What are the structures of the sternum?
Manubrium Mesosternum Xiphoid process
What are the two chest wall deformities to be aware of?
Pectus excavatum (ditch) Pectus carinatum (peak)
What structures are in the superior thoracic aperature?
- Oesophagus - Trachea - Vagus / phrenic nerve - Sympathetic chain - Major arteries off the aorta - Major veins to the heart - Apex of lungs (very imp. for central line placement) - Other nerves / vessels
What is the primary muscle for respiration at rest?
Diaphragm
What are some major structures passing through the diaphragm and at what levels?
IVC (@T8 b.c vena cava = 8 letters) Oesophagus (T10 b.c 10 letters) Aorta (@T12 b.c Aortic hiatus = 12 letters) Vagus (cardiac plexus) Splanchnic nerves (abdo plexus) Thoracic duct
What are the muscles of the thoracic wall?
- Intercostal muscles - (Subcostal and transversus thoracis)
What are the three muscle layers of the thoracic wall?
External intercostal Internal intercostal and innermost intercostal (neurovascular plane)
What are the intercostal nerves?
- Anterior rami - MOTOR AND SENSORY - 12th nerve is subcostal otherwise one per an intercostal space
What sort of action do the ribs have during breathing?
Upper ribs: More lateral axis; “pump handle’ movement Lower ribs: More post. axis “Bucket handle movements”
What are the anterior intercostal arteries?
Ribs 1-6; Internal thoracic (divides into musculophrenic and sup. epigas) Ribs 7-9; Musculophrenic
What are the posterior intercostal arteries?
1&2 from supreme intercostal a. (branch of costocervical trunk from subclavian art.) 3-11 and subcostal from thoracic aorta
Where do anterior and posterior intercostal veins drain?
Ant -> Internal thoracic vein Post -> Azygous/Hemiazygous venous system
When describing the intercostal spaces, how many vessels / nerves are there?
2 arteries (ant and post) 2 veins (ant. and post.) one nerve.
What can be an issue of scoliosis?
Asymmetry in the lung cavities therefore differences in their size?
What exists between the ribs and sternum?
Costal cartilage
