Summary Netter\'s Anatomy lecture lungs PDF

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Thoracic Cavity – Lungs: Thoracic cavity: subdivided into three major compartments: - Left pleural cavity surrounding a lung - Right pleural cavity surrounding a lung - Mediastinum Thoracic Wall and Cavity: - The superior margin of the manubrium is in approximately the same horizontal plane as the invertebral disc between the vertebrae TII and TIII - Pleural cavities is that they extend above the level of rib I - The apex of each lung actually extends into the root of the neck - Abnormal events in the root of the neck can involve the adjacent pleura and lung

Superior Thoracic aperture

A. Inferior Thoracic aperture

B. diaphragm

Pleura - Pleural cavity is completely lined by a mesothelial membrane called the pleura - The pleura lining the walls of the cavity is the parietal pleura - Whereas that reflected from mediastinum at the roots and onto the surfaces of the lungs is the visceral pleura - Each pleural cavity only a very thin layer of serous fluid

Pleural Cavities

3. Pleural cavities and Lungs - right pleural cavity o contains the right lung - left pleural cavity o contains the left lung - mediastinum o midline structure o contains  heart  great vessels  esophagus

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trachea other structures

Parietal Pleura - the names given to the parietal pleura o costal part o diaphragmatic part o medistinal part o cervical pleura (dome of pleura or pleural cupola)

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covering the superior surface of the cervical pleura is a distinct dome-like layer of fascia, the suprapleural membrane

b. Parietal Pleura -

recesses is where two layers of parietal pleura become opposed costmediastinal recesses costodiaphragmatic recesses

Parietal pleural reflections and recesses Lung Anatomy: - base sits on the diaphragm - the apex projects above rib 1 and into the root of the neck - the two surfaces: o the costal surface lies immediately adjacent to the ribs and intercostal spaces of the thoracic wall o the mediastinal surface lies against the mediastinum anteriorly and the vertebral column posteriorly

Lung Anatomy: - within each root and located in the hilum are: o a pulmonary artery o two pulmonary veins o a main bronchus o bronchial vessels o o

nerves lymphatics

This pulmonary ligament may stabilize the position of the inferior lobe and may also accommodate the down and up translocation of structures in the root during breathing -

The right lung has three lobes and two fissures The left and lung is smaller than the right lung The medial surface of right lung lies adjacent to a number of important structures: o Heart o Inferior vena cava o Superior vena cava o Azygos vein o Esophagus

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The medial surface of the left lung lies adjacent to o Heart o Aortic arch o Thoracic aorta o And esophagus Has 2 lobes and one fissure

Transverse Plane 1. External intercostal mm 2. Serratus posterior superior m

Vertical Plane: - Diaphragm

The Bronchial Tree - The trachea is held open by C-shaped transverse cartilage rings embedded in its wall-open part of the C facing posteriorly - The lowest tracheal ring has a hook-shaped structure, the carina, that projects backwards in the midline between the origins of the two main bronchi - The posterior wall of the trachea is composed mainly of smooth muscle - The walls of the bronchi are held open by discontinuous elongated plates of cartilage, but these are not present in bronchioles

A. Bronchial Tree

B. Bronchopulmonary segments

Bronchial Tree - The main bronchus divides into: o Lobar bronchi (secondary bronchi)  Segmental bronchi (tertiary bronchi) which supplies bronchopulmonary segments  Bronchioles  Respiratory surfaces - The walls of the bronchi are held open by discontinuous elongated plates of cartilage, but these are not present in bronchioles

Bronchial Tree - Right main bronchus is wider and takes a more vertical course through the root and hilum than the left main bronchus - Inhaled foreign bodies tend to lodge more frequently on the right side than on the left Bronchi Tree - A bronchopulmonary segment is the smallest, functionally independent region of a lung and the smallest area of lung that can be isolated and removed without affecting adjacent regions - There are ten bronchopulmonary segments in each lung Pulmonary Circulation - The right and left pulmonary arteries originate from the pulmonary trunk and carry deoxygenated blood to the lungs from the right ventricle of the heart - On each side a superior pulmonary vein and an inferior pulmonary vein carry oxygenated blood from the lungs back to the heart - The bronchial arteries and veins constitute the nutritive vascular system of the pulmonary tissues

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Pulmonary vessels

Bronchial Arteries - Constitute the “nutritive” vascular system of the pulmonary tissues - Originate from the thoracic aorta or one of its branches: o A single right bronchial artery normally arises from the third posterior intercostal artery (but occasionally, from the upper left bronchial artery) o Two left bronchial arteries arise directly from the anterior surface of the thoracic aorta

The Bronchial veins drain into: - The bronchial veins drain into: o Pulmonary veins or the left atrium o Azygos vein o Superior intercostal vein o Hemiazygos vein

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Each lung remains attached to the mediastinum by a root formed by the airway, pulmonary blood vessels, lymphatic tissues and nerves

Innervation of the Lung - Anterior pulmonary plexus - Posterior pulmonary plexus - Visceral efferents from: o The vagus nerves constrict the bronchioles o

The sympathetic system dilates the bronchioles

Nerves in the Mediastinum - The vagus nerves pass immediately posterior to the roots of the roots of the lungs

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Phrenic nerves pass immediately anterior to them

Lymphatic drainage of Lungs: - Superficial of subpleural and deep lymphatics of the lung drain into lymph nodes called tracheobronchial nodes - Parasternal nodes - Brachiocephalic nodes - Brachiomediastinal trunks o These trunks drain directly into deep veins at the base of the neck, or may drain into the right lymphatic trunk or thoracic duct

In the Clinic: imaging the lungs:

Left to Right Venous Shunts:

Clinical Notes: - Lung Emphysema: progressive loss of elastic recoil - Pneumothorax: puncture in chest wall (stab wound)  collapsed lung - Lung resection: removal of segment, lobe, or entire lung - Bronchial asthma: constriction of bronchial smooth muscle - Pigmented lungs: carbon particles carried by phagocytes to periphery...