Thorax, Tracheobronchial Tree & Lungs Flashcards
What vertebral levels are the following found at?
Suprasternal (jugular) notch
Sternal angle
Xiphoid process
Suprasternal (jugular) notch - T2
Sternal angle - T4/5
Xiphoid process - T9/10
Which vertebrae would articulate with rib 5?
T4 AND T5
Most ribs articulate with their own vertebrae and the one ABOVE
How can the ribs be classified?
Vertebrosternal - Ribs 1-7
Vertebrocostal - Ribs 8-10
Floating - Ribs 11 and 12
Within which intercostal muscles does the main neurovascular bundle run?
Between the internal and innermost intercostal mucle layers
What are the external and internal intercostal muscles involved in?
External - inspiration
Internal - expiration
Should chest drains be inserted in the superior or inferior part of intercostal spaces?
Inferior - avoid main neurovascular bundle
What is the revised triangle of safety? What is it used for?
Thoracostomy (chest drain)
4th intercostal space between midaxillary line and ant axillary fold
Which is the nerve supply of the intercostal space and the surrounding tissue? (both motor and sensory)
Ventral rami of spinal nerves
Dermatomal arrangement - e.g. shingles can be to a dermatome
What can lead to Horner’s syndrome?
Pancoast tumour - apical lung tumour
What do anterior and posterior instercostal arteries arise from? What happens to both of them?
Ant - arise from internal thoracic and musculophrenic a
Post - arise from descending aorta
Form an anatomoses
What is the drainage system of the thoracic wall?
UNPAIRED (Azygous) system
R.side - azygous v -> SVC
L.side - accessory azygous or hemiazygous v -> cross midline -> SVC
Where does the thoracic duct drain to?
Left subclavian vein
What nerve innervates the diaphragm?
Phrenic nerve = C3,4,5 - motor and sensory
+ sensory on periphery - intercostal nerves
Gallbladder inflammation - shoulder pain
At what vertebral levels do structures pierce the diaphragm?
IVC - T8
Oesophagus - T11-T12
Aorta - T12
What congenital diaphragmatic defects can occur?
Posterolaterally - Bochdalek
Retrosternally - Morgagni
Where does the respiratory system develop from?
Outgrowth of the gut tube - resp diverticulum (4 wks)
Lung/bronchial buds -> splanchno-pleuric Mesoderm
Embryologically, how does the oesophagus separate from the trachea?
Tracheo-oesophageal septum
How many bronchial buds are there on the right and left side?
R = 3 L = 2
Why might a premature baby have very little chance of survival before 26 weeks?
Respiratory epithelia begins developing at 26 weeks
When do all major lung parts develop?
16 weeks
Full lung maturation = 7-10 yrs
What fissures and lobes do the right and left lungs have?
R = 3 lobes/ oblique and horizontal fissure L = 2 lobes/ oblique fissure
Where does the phrenic nerve and vagus nerve pass in relation to the lung?
Phrenic = Anterior to hilum Vagus = posterior to hilum
Where do recurrent laryngeal nerves branch from and how do they enter the thorax?
Vagus nerve
R. RLN recurs at right lung apex under right subclavian artery
L. RLN recurs at lung hilum/aortic arch
So what might happen in a patient with an aortic arch aneurysm?
Hemiparalysis of vocal cords - L. RLN -> hoarse voice
What is the pleural cavity?
Space between visceral and parietal pleura - surface tension holds them close together
What is pleural catch?
Slouching - push visceral and parietal pleura together, and fluid out.
Stop slouching - fluid returns - parietal pleura is somatically innervated - feel a stabbing pain
What is haemothorax?
Air in pleural cavity
What is effusion?
Fluid leaking out of lung into pleural cavity
What is tension pneumothorax?
Air entering pleural cavity but not leaving - constant overfilling leads to: Mediastinal shift Tracheal deviation Diaphragmatic depression Unilateral hyperinflation Increased intercostal space size Hyper-resonant
How do you treat tension pneumothorax?
Needle Decompression
Wide bore needle - 2nd intercostal space at midclavicular line
What is the costadiaphragmatic recess?
where the parietal pleura reflects forms a recess between the thoracic wall and diaphragm
At what level does the trachea bifurcate?
T4/5
Where are the horizontal and oblique fissures of the right lung?
Horizontal - 4th CC
Oblique - T3 Spinous Process to 6th cc anteriorly
Where would you auscultate the upper, middle and inferior lobe?
Upper - anterior
Inferior - posterior
Middle - axillary lines (Breast tissue and pec major in the way at the front)
What nerve does the revised triangle of safety avoid?
Long thoracic n
Which bronchus is more vertical and wider?
R side - aspirate food
Can bronchopulmonary segments be resected?
Yes - Smallest functionally independent region of lung that can be resected without affecting other regions
have own blood and air supply
What are the walls of trachea supported by?
C - shaped cartilage
hyaline cartilage
Describe the lymphatic drainage of the lungs.
Majority of lymphatic drainage is to right lymphatic duct / subclavian vein
Left upper lobe - Thoracic duct / left subclavian vein
