• Lung
• Serous plural sac (side of the body)
• Lung is outside and surrounded by the pleural sac

• Wall of each pleural sac consists of a continuous serous membrane or mesothelium (pleura)
• Parietal pleura
• Visceral pleura
• Pleural sleeve
• Pleural cavity

• Pleura that adheres to thoracic wall, mediastinum, and diaphragm

• Pleura that adheres to lungs

• Area of continuity between parietal and visceral pleurae

• Has a small amount (<10ml) of serous fluid for lubrication

• Inflammation of visceral and parietal plura (pleuritis) makes them sticky
• Increased friction between the pleurae creates a pleural rub that is accompanied with sharp pain

Named Regions of parietal pleura 

Palpate: Cervical, costal, mediastinal, diaphragmatic, superior thoracic aperture

• Injuries to the base of the neck can affect lungs and pleura because cervical pleurae extends 2-3cm above the superior thoracic aperture

• Abrupt change in direction between adjacent pleural regions
• Left & right sternal lines of pleural reflection
• Left & right costal lines of pleural reflection
• Left & right vertebral lines of pleural reflection
• Junction betwen costal and mediastinal parietal pleura at the sternal lines are asymmetric
• Left sternal line of reflection deviates laterally spanning ribs 4-6
• Left lateral deviation exposes an anterior access location to mediastinum 

• Crosses rib 8 at the midclavicular line
• Crosses rib 10 at the midaxillary line
• Ends at rib 12 at the paravertebral line

• Gutters
• During breathing, lungs do not entirely fill the pulmonary cavities
• Costomediastinal recess
• Costodiaphragmatic recess

• Associated with sternal pleural reflection and cardiac notch (which is bigger in the left lobe than the right lobe)

• Associated with costal pleural reflection

• Midclavicular line of lungs is rib 6, parietal pleura is rib 8
• Midaxillary line of lungs is rib 8, pareital pleura is rib 10
• Paravertebral line is rib 10, parietal pleura is rib 12
• Helps to know where to safely put needle

• Costodiaphragmatic is a potential space that can fill with fluid
• When upright, excess fluid will accumulate in the recess
• As patient exhales, clinically a syringe can be put between the ribs 9 and 10 (9th intercostal space)

• Organs of respiration (gas exchange)
• Spongy and pink (air polution darkens lungs)
• Inflates with air during inspiration and elastically recoils during  exhalation

• Each lung is surrounded by own independent pleural sac (and cavity)
• Pleural cavity is under negative pressure- keeps lungs inflated during inspiration
• Breach of pleura releases suction in the affected cavity- elastic recoil causes the lungs to collapse
• Entry of air into the pleural cavity due to a fractured rib

• Elastic recoil causes the lungs to collapse

• Entry of air into the pleural cavity

• Pneumothorax
• Hydrothorax
• Hemothorax
• Chylothorax

• Excessive serous fluid in pleural cavity

• Blood in pleural cavity

• Lymph in the pleural cavity

• Start with fluid prefix and then air in the middle, and then thorax

• Between lungs and pleura
• Contains all thoracic viscera and structures, except for the lungs
• Leave impressions on cadaveric lungs
• Root of the lungs

• Lungs attached to the mediastinal structures by this
• Major components are
• Main bronchus
• Pulmonary arteries
• Pulmonary veins

• Structures forming the root of the lung enter and exit this location

• Surrounds the root of the lung

• Slack in the pleural sleeve forms this

• Pulmonary arteries are superior
• Bronchi are posterior
• Pulmonary veins are anterior-inferior
• Pulmonary ligaments are inferior to pleural sleeve

• Apex 
• Superior end that extends the base of the neck
• Anterior border is wedge like
• Posterior border is rounded
• Inferior border
• Anatomical base of lung
• Concave
• Wedge-like at costodiaphragmatic recess
• Blunt at mediastinum

• Costal
• Mediastinal
• Diaphragmatic

• Has 3 lobes
• Superior
• Medial
• Inferior
• Has 2 fissures that separate the lobes
• Oblique fissure (separates superior from inferior and inferior from medial)
• Horizontal fissure (separates superior from medial

• 2 Lobes
• Superior and Inferior
• Fissure
• Just the oblique fissure
• Two unique things
• Cardiac notch
• Lingula of superior lobe

• Begins below the larynx
• Tree branches into smaller successive tubes
• Ends at alveoli with capillary beds for exchange

• Palpable at the jugular notch
• Begins at the C6 vertebral level
• Ends at the T4/T5 IVD level (sternal angle or transverse thoracic plane)
• At end bifurcates into the 2 main bronchi
• Has C-shape cartilage that is then finished off by smooth muscle called the trachealis

• Used to examine the inside (lumen) of the airway

• "Keel of boat"
• Usually at T4/T5 IVD level
• Thin ridge of cartilage
• Marks branching of trachea into the main bronchi

• Widening or distortion of the carina usually indicates carcinoma of the lymph nodes where the trachea bifurcates

• Trachea bifurcates into R&L main (primary) bronchi
• The right main bronchus is wider and more vertical than the left main bronchus
• Clinically: Forein bodies and objects are more likely to be lodged in the right main bronchus

• Each main bronchus branches into:
• Lobar (secondary) bronchi
• 2 Left, 3 Right
• Each lobar bronchus branches into:
• Segmental (tertiary) bronchi
• 10 right
• 10 (or 8) left
• Each segmental bronchus supplies a wedge-shaped region called a bronchopulmonary segment

Bronchopulmonary Segments

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Right lung down:

• Apical
• Posterior
• Anterior
• Lateral
• Medial
• Anterior Basal
• Lateral Basal

Right lung medial:

• Superior
• Medial 
• Posterior Basal

Left lung medial:

• Superior
• Posterior basal

Left lung down:

• Apicoposterior
• Anterior
• Superior lingular
• Inferior lingular
• Anteromedial basal
• Lateral basal

• Each segment in BP Segments have independent vasculature and is separated by connective tissue
• Diseased BP segment can be resected without interrupting neighboring segment
• Lobectomy is cutting out an entire lobe
• Pneumonectomy is cutting out an entire lung

• Distal buds of the tree
• Goes from segmental bronchus to conducting bronchiole (lack supporting cartilage)
• Conducting bronchiole->terminal bronchiole->respiratory bronchiole->alveolar ducts->alveolar sac->alveolus
• Alveolus is where gas exchange occurs

• Pulmonary Artery
• Supply oxygen-deficient blood from heart to lungs for oxygenation
• Follows branching and course of airways
• Connect to capilllary beds surrounding alveoli where respiration occurs
• Mainly supply blood to the lung parenchyma

• Bronchial arteries
• Supply high O2 blood to root of lungs, stroma of lungs, visceral pleura, and upper esophagus
• Left bronchial artery branches off thoracic aorty
• Right brachial artery is variable and comes from thoracic aorta, left bronchial artery, and posterior intercostal artery
• Anastomose with pulmonary arteries in walls of bronchioles and visceral pleura

• Bronchial veins
• Right bronchial veins-> azygos vein
• Left bronchial veins->accessory hemiazygos vein
• Remainder of blood in lungs and visceral pleura is drained by the pulmonary vein

• Drain high O2 blood from capillaries to the heart
• Drain low O2 blood from visceral pleura
• Course independently of the arteries and airways
• Merge into the 2 left and 2 right veins at the hilum

Innervations of Lungs and Pleurae (Pulmonary Plexus)

• Anterior and posterior to the root of lung
• Innervates lungs
• Parasympathetic motor fibers from CN X (Vagues nerve) which is preganglionic
• Sympathetic motor fibers from sympathetic trunks (postganglionic)
• Vagus nerve activates bronchoconstriction
• Sympathetic trunks activate bronchodilation
• Visceral pleura and parenchyma insensitive to pain from mechanical damage

• Intercostal nerves and phrenic nerves innervate the parietal pleura and convey localizaed pain

• Drained by veins of thoracic wall and supplied by arteries of thoracic wall

• Communicate freely between left and right sides
• Drain sequentially to tracheobronchial nodes ->paratracheal nodes->right lymphatic and thoracic ducts

• Subpleural origin (just beneath visceral pleura origin)
• Drains lymph from lung
• Parenchyma and visceral pleura to hilar (bronchopulmonary) nodes

Deep lymphatic plexus of lungs

• Originates in walls of airways and surrounding stroma
• Drains lymphs from structures that form root of lung

• Lymph in right lung->right venous angle
• Lymph in left inferior lobe->right venous angle
• Lymph in left superior lobe-> left venous angle
• Can be used to determine metastasis of lung cancer using the lymphatic plexuses and access to venous circulation 

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• General term for any type of lung cancer