5. Lungs

• Pleurae

  2 parts: Visceral pleura and Parietal pleura
• 4 subdivisions of the pleurae

  • Costal pleura
  • Mediastinal pleura
  • Diaphragmatic pleura
  • Cervical pleura/ CUPULA
• Pleural cavity

  Potential space between the Parietal and Visceral Pleurae with a fluid around 10 to 20 ml
• Costal line of Pleural reflection passes obliquely across the: 8th rib in MCL, 10th rib in MAL, 12th rib sides of vertebral column
• Lower margin of Lungs crosses the: 6th rib in MCL, 8th rib in MAL, 10th rib sides of vertebral column
• Thoracocentesis


  Surgical puncture of the thoracic wall into the pleural cavity for aspiration of fluid
• Thoracocentesis is performed at or posterior to the midaxillary line one or two intercostal spaces below the fluid level but not below the 9th intercostal space. IDEAL SITE is 7th, 8th or 9th intercostal space
• Needle should be inserted immediately ABOVE the superior margin of a rib
• Parietal pleura


  Sensitive to pain, touch, temperature and pressure
• Visceral pleura


  Insensitive to common sensation but sensitive to stretch
• Right lung has 3 lobes, with horizontal and oblique fissures, larger, heavier, shorter and wider than left
• Left lung has 2 lobes, with oblique fissure
• Parts of each lung

  • Apex
  • 3 surfaces
  • 3 borders
• Right lung


  Mean weight - 445 gms, larger, heavier but shorter and wider than the left, with 3 lobes, with 2 fissures, with 3 lobar bronchi and 10 segmental bronchi, has grooves for SVC, arch of Azygous vein, Esophagus
• Left lung


  Mean weight - 395 gms, with 2 lobes, with only 1 fissure, with 2 lobar bronchi and 8 to 10 segmental bronchi, contains the LINGULA that corresponds to the middle lobe of R lung, contains Cardiac impression / notch, has grooves for Aortic arch, Descending aorta
• Right lung lobes

  • Superior
  • Middle
  • Inferior
• Right lung fissures

  • Horizontal
  • Oblique
• Left lung lobes

  • Superior
  • Inferior
• Left lung has 1 fissure - oblique
• Left lung has a deep cardiac notch
• Left lung contains the lingula
• Root of the lung

  Content: bronchi, pulmonary artery, pulmonary veins, lymph vessels, bronchial vessels, where parietal and visceral pleura meet
• Bronchopulmonary segments


  Pyramidal-shaped, apex directed to lung root, largest subdivision of a lobe, named according to the segmental bronchus supplying it, separated from adjacent segments by connective tissue, has its own bronchus, arterial supply, venous drainage, lymphatic drainage, anatomical and surgical unit of lung
• Superior lobe breath sounds auscultated on the anterior and superior aspects of the thoracic wall, inferior lobe on the posterior and inferior aspects of the back, middle lobe on the anterior chest wall near the sternum, inferior to the right 4th costal cartilage
• Adventitious breath sounds


  • Wheezes
  • Rhonchi
  • Crackles or rales
  • Stridor
• Lobar pneumonia - transmitted voice sounds louder, tactile fremitus increased

  Pleural effusion - transmitted voice sounds softer, tactile fremitus decreased

  COPD - transmitted voice sounds softer, tactile fremitus decreased
• The bronchogram of a 45 y/o female smoker shows the presence of a tumor in the eparterial bronchus. The airway most likely blocked is the right superior bronchus.
• The eparterial bronchus is the right superior lobar (secondary) bronchus. All of the other bronchi are hyparterial bronchi.
• A thoracic surgeon removed the right middle lobar bronchus along with a lung tissue from a 57 y/o heavy smoker.
• Eparterial bronchus


  The right superior lobar (secondary bronchus)
• Hyparterial bronchi


  All the other bronchi
• Foreign body aspiration


  • More likely to enter the right main bronchus because it is shorter, wider and more vertical than the left main bronchus

  In a patient who is standing or sitting, the foreign body tends to become lodged in the posterobasal segment of the inferior lobe of the right lung
• Bronchial arteries


  From descending thoracic aorta
• Pulmonary arteries


  From pulmonary trunk

  Left is shorter and narrower, arches over the Left primary bronchus

  Right runs under the arch of the aorta
• Bronchial veins


  Drain into azygous and hemiazygous veins
• Pulmonary veins


  Four (4) empty into left atrium
• Pancoast tumor


  • Superior Pulmonary Sulcus tumor – malignant neoplasm involving the APEX of the lung

  PANCOAST SYNDROME:

  LOWER TRUNK BRACHIAL INJURY – pain radiating to shoulder and medial aspect of the arm; atrophy of muscles of the forearm and hand

  LESIONS of CERVICAL SYMPATHETIC GANGLIA – with HORNER syndrome (ptosis, enopthalmos, miosis, anhydrosis and vasodilation)
• Superficial / Subpleural plexus

  Lies deep in visceral pleura & drains lymph from the surface to the hilum of lung
• Deep plexus


  Lies in the lung
• Lymph drainage flow


  Superficial plexus and Deep plexus → drain into Bronchopulmonar / Hilar LN → Tracheobronchial (Inferior–Superior) LN → Paratracheal LN → Bronchiomediastinal LN and trunks → eventually to the Thoracic Duct on the Left side and Right Lymphatic duct on the Right side