Ribs Sternum Thoracic Joins and Breathing movements

Ribs + sternum + thoracic joins + breathing movements ●​ Rib classification ○​ True ribs ■​ 1-7 ■​ Attachment directly to sternum ■​ Costal cartilage ○​ Flase ribs ■​ 8-10 ■​ Attatches indirectly ■​ Cartilage joins rib 7 cartilage ○​ Floating ribs ■​ 11-12 ■​ No attachment ●​ Typical ribs 3-9 ●​ Atypical ribs 1,2,10,11,12 ○​ Head ■​ Usually 2 facets ■​ Articulation with vertebral bodies ○​ Neck ○​ Tubercle ■​ Articulation with transverse processes ○​ Angle ○​ Shaft and costal groove ■​ Inferior border ■​ ○​ Rib 1 ■​ ■​ ■​ VAN protection Short broad Most curved Scalene tubercle ●​ Attachment to anterior scalene ■​ Groove for subclavian vein ■​ Groove for subclavian artery (posterior) ○​ Rib 2 ■​ Thinner compared to rib 1 ■​ Tuberosity for serratus anterior ●​ Identifying feature ○​ Rib 10 ■​ Single facet on head ■​ Transitions towards floating style ○​ Rib 11-12 ■​ Single facet on head ■​ No neck/tubercle ●​ No costotransverse joints ■​ Floats on anterior fashion Sternum anatomy ●​ Manubrium ○​ Clavicular notches ○​ Jugular notch ●​ Body ●​ Xiphoid process ●​ Sternal angle ○​ Angle of Louis ○​ Junction of manubrium and body ○​ Landmark for 2nd costal cartilage ■​ Used to cont ribs and spaces Thoracic inlet ●​ Superior opening of the thorax ●​ Communicates directly with root of neck ●​ Major visceral structures ○​ Airway ○​ Food ●​ Vessels and nerves pass between neck and superior mediastinum ●​ Posterior ○​ Body of T1 vertebra ●​ Lateral ○​ 1st rib ○​ Costal cartilage ●​ Anterior ○​ Superior border - manubrium ●​ Inlet slopes downwards anterior to posterior ○​ Critical ■​ Pleural dome ■​ Apex relation ●​ Viscera ○​ Midline core ■​ Trachea is anterior to esophagus (immediate) ■​ Based on neck and superior mediastinum region ●​ Vessels and nerves ○​ Major vessels and nerves will pass anterior laterally to trachea and esophagus via inlet ○​ Subclavian arteries ■​ Arch upwards ●​ Into root of neck ●​ Pass through anterior and pleural dome ●​ Posterior → Anterior scalene ○​ Crosses through rib 1 ○​ Axillary artery ●​ Pleural dome and lung apex ○​ Cupula ○​ Cavity will extend around 2-3cm ■​ Above rib 1 ■​ Into neck ●​ Cervical parietal pleura ○​ Cupula ●​ Apex ○​ Apical part ○​ Superior lobe of the lung ●​ Due to its inlet slope… ○​ Anteriorly pleura is able to extend above manubrium ○​ Could also cross over rib 1 ○​ Posteriorly will remain below T1(top part) ●​ Upper limb​ ○​ Axillary inlet is beside thoracic inlet ■​ Big vessels ■​ Brachial plexus ⇒ Upper limb going over rib 1 Transverse thoracic plane ●​ Horizontal reference plane ○​ Sternal angle anterior ■​ Angle of Louis ○​ T4-T5 intervertebral disc on posterior side ●​ Superior mediastinum and inferior mediastinum gets separated Structures in near proximity of T4, and T5 plane ●​ Big four ○​ Beginning and end of aortic arch ■​ Ascending aorta → arch starts ■​ Arch → descending thoracic aorta begins ○​ Tracheal bifurcation ■​ Carnia ○​ Azygos vein arch ■​ Drains into SVC ○​ Thoracic duct crosses ■​ Right → left ■​ Around upper thorax ■​ Levels might vary… but is common here ●​ Others… ○​ Pulmonary trunk bifurcation ■​ R/L pulmonary arteries ■​ Close proximity ○​ Ligamentum arteriosum ■​ Near aortic arch ■​ Close to left pulmonary artery region ●​ Close to left recurrent laryngeal loops ○​ Left recurrent laryngeal nerve ■​ Under arch in this region ■​ Clinically hoarseness ■​ Arch pathology Cx..How it is seen ●​ Sternal angle palpation ○​ Need when finding for 2nd rib ■​ Starts pointing for counting ribs and intercostal spaces ●​ Carina irritation ○​ Aspiration ○​ Secretions ○​ Triggers strong cough ○​ Significant for bronchoscopy localization ●​ Aortic arch aneurysm ○​ Close to this plane will be in part of compression of… ■​ Trachea ●​ Breathing noise ●​ Stridor ■​ Esophagus ●​ Dysphagia ■​ Left recurrent laryngeal nerve ●​ Hoarseness Memorization tools ●​ Manubrium in sternal angle ○​ Great vein ■​ SVC region ○​ Aortic arch ○​ Trachea ■​ Carina nearby ○​ Esophagus ○​ Thoracic duct and vertebral column ■​ T4/5 Intercostal space-Thoracic wall ●​ 11 intercostal spaces between 12 ribs ○​ 3 layers of intercostal muscles ■​ External ●​ Fiber direction​ ○​ Hands-in-pocket” ○​ Infero-anterior ●​ From rib tubercle posteriorly to costochondral junction anteriorly ●​ Anteriorly replaced through external intercostal membrane ●​ Elevation of ribs ○​ Inspiration ○​ Quiet inspiration ■​ Internal ●​ Fiber direction ○​ Roughly perpendicular to external ○​ Infero-posterior ●​ Extent ○​ Sternum anteriorly ○​ To rib angle posteriorly ○​ Posteriorly replaced by internal intercostal membrane ●​ Forces expiration ○​ Interosseous part ●​ Interchondral part = Assist inspiration ○​ High yield nuance ■​ Innermost group ●​ Not one uniform sheet ○​ Innermost intercostal ■​ Lateral ○​ Subcostales ■​ Posterior span ■​ >1 space ○​ Transversus thoracic ■​ Anterior ■​ Inner surface of sternum ●​ Assist internal intercostal ●​ Stabilize interspace ○​ Intercostal neurovascular bundle ○​ Endothoracic fascia ○​ Partial pleura deep to muscle Neurovascular bundle (VAN) ●​ Main bundle location ○​ Costal groove on inferior border of rib ○​ Internal muscle layer ○​ Innermost muscle layers ●​ VAN ○​ Superior → inferior ○​ With groove ●​ Collateral bundle ○​ Smaller branches near superior border of rib (below) ○​ Cx ■​ Safest needle path ■​ Above rib below Thorax cheatsheet ●​ Thoracic aperture ○​ Thoracic inlet ■​ Boundaries ●​ T1 - posterior ●​ Rib 1 - lateral ●​ Manubrium - anterior ■​ Contents concepts ●​ Trachea ●​ Esophagus ●​ Major vessels ●​ Nerves ■​ Pleural cupula and lung apex ●​ Extending into neck above rib 1 ⇒ neck procedures will risk pneumothorax ○​ Thoracic outlet ■​ Inferior thoracic aperture ■​ Boundaries ●​ T12 ●​ Ribs 11-12 ●​ Costal margin ●​ Xiphoid ■​ Closed by diaphragm ●​ T8 = IVC ●​ T10 = esophagus + vagal trunk ●​ T12 = aorta + thoracic duct ○​ Azygos ●​ Transverse thoracic plane ○​ Sternal angle T4/5 disc ○​ Landmarks ■​ Start and end of aortic arch ■​ Tracheal bifurcation ●​ Carina ■​ Azygos arch → SVC ■​ Separation of superior and inferior mediastinum ●​ Mediastinum compartments ○​ Superior mediastinum front to back ■​ Thymus ■​ Veins ■​ Arteries ■​ Trachea ■​ Esophagus ■​ Thoracic duct ○​ Inferior mediastinum ■​ Anterior ●​ FAt nodes ●​ Thymic remnant ●​ 4 Ts mass DDx) ■​ Middle ●​ Heart + pericardium ●​ Great vessel roots ●​ Phrenic nerves ■​ Posterior ●​ Descending aorta ●​ Esophagus ●​ Thoracic duct ●​ Azygos ●​ Sympathetic splanchnics Key nerve relation at lung root ●​ Phrenic anterior ●​ Vagus posterior