Anatomy of Lungs and Pleurae PDF

Anatomy of Lungs and Pleura Objectives ◼ ◼ ◼ ◼ ◼ ◼ Describe the anatomy of the pleura (visceral and parietal) and understand the sealed-pleural cavity. Describe the basic anatomical features of the lungs Understand the significance of bronchopulmonary segment Describe the blood supply, lymphatic dra...

Anatomy of Lungs and Pleura Objectives ◼ ◼ ◼ ◼ ◼ ◼ Describe the anatomy of the pleura (visceral and parietal) and understand the sealed-pleural cavity. Describe the basic anatomical features of the lungs Understand the significance of bronchopulmonary segment Describe the blood supply, lymphatic drainage and innervation of the lungs Describe the anatomy of the posterior mediastinum Describe the origin, course and termination of the thoracic duct Lower Respiratory Tract: Overview Nasal cavity Pharynx Larynx Trachea Bronchus Bronchioles RIGHT LUNG Martini's Human Anatomy Figure 24.1 LEFT LUNG 3 The human body is not a solid object. We have organs which are found within chambers known as body cavities. The brain is found within the cranial cavity, the spinal cord is located in the vertebral or spinal cavity. These 2 cavities are found on the dorsal aspect of the body and some authors refer to both as the dorsal body cavity. On the ventral aspect of the body is the ventral body cavity. This cavity contains the organs of respiration, cardiovascular, digestive, reproductive and urinary systems. 4 Thoracic Cavity: Introduction B ◼ Viscera are housed within body cavities ◼ The thoracic cavity has three subdivisions:  Medially is the mediastinum (A)  Laterally are pleural cavities (B), surround the lungs B A Martini's Human Anatomy Figure 1.14 5 The Pleura and Pleural Cavity Parietal pleura Visceral pleura Pleural cavity Human Anatomy McKinley & O’Loughlin, 2008 Figure 1.10 Histology of Pleura ◼ Serous membrane that invests the lungs ◼ Consists of:  Simple squamous epithelium Subserous fascia (loose areolar CT) Parietal and visceral portions are histologically identical, continuous with each other  ◼ 7 Parietal Pleura ◼ Regionally named by its relationship to chest wall Cervical: Covers the apex of the lung in the neck region  Costal: Lines ribs and intercostal surfaces  Diaphragmatic: Lines thoracic surface of diaphragm  Mediastinal: Lines the mediastinum  ◼ Gray’s Anatomy for Students Figure 3.24 Innervation:  Phrenic nerve: Mediastinal and central part of diaphragmatic pleura  Intercostal nerves: Costal and peripheral part of diaphragmatic pleura 8 Pleurisy Grant’s Atlas of Anatomy Figure 1.22 ◼ ◼ Sharp, stabbing pain upon respiration Inflammation of:  Costal pleura: Local dermatomal pain through intercostal nerves  Mediastinal pleura: Referred pain through phrenic nerve (C3-5) 9 Pleural Recesses: Overview ◼ Potential spaces for lung expansion during forced inspiration  Also for fluid collection and spaces from which fluid can be aspirated 10 Pleural Recesses Gray’s Anatomy for Students Figure 3.38 ◼ ◼ Costodiaphragmatic recesses: Found between costal and diaphragmatic pleura Costomediastinal recess: Located between costal and mediastinal pleura (large on the left side) 11 Pleural Cavity Normal Chest x-ray Pleural Effusion Pneumothorax 12 Tension Pneumothorax ◼ ◼ ◼ Life threatening medical emergency Occurs when a piece of tissue forms a flap over the wound Characterized by:  Air entry into pleural cavity during inspiration, leads to mediastinal shift   Prevention of air escape from pleural cavity by flap of tissue in expiration Increased intrathoracic pressure, further mediastinal shift  Reduction of opposite lung function, decrease venous return to heart 13 Thoracentesis Grant’s Atlas of Anatomy Figure 1.22 Snell’s Clinical Anatomy for Students 14 Trachea Carina: Ridge of tissue at bifurcation of trachea Martini's Human Anatomy and Physiology Figure 24.7 ◼ Fibrocartilaginous tube from C6 to T4/T5  ◼ ◼ In deep inspiration, reaches the level of T6 Anterolateral: U-shaped bars of hyaline cartilage Posterior: Smooth muscle (trachealis) 15 Bronchi ◼ Primary (main) bronchi    ◼ Secondary bronchi   ◼ Martini's Human Anatomy and Physiology Figure 24.7 Extend from carina to lung hilum Right bronchus: Wider, shorter and more vertical Left bronchus: Narrower, longer and more horizontal Right: Superior, middle and inferior Left: Superior and inferior Tertiary (segmental) bronchi  Supply bronchopulmonary segment 16 Relationship of Trachea and Bronchi Moore’s Clinically Oriented Anatomy Figure 1.38 17 Morphological Features of Lungs Horizontal fissure Superior lobe Superior lobe Inferior lobe Middle lobe Inferior lobe Oblique fissure Human Anatomy McKinley & O’Loughlin, 2008 Figure 25.13 ▪ The right lung has three lobes separated by two fissures ▪ The left lung has two lobes separated by one fissure 20 Hilum vs Root of Lungs Pulmonary artery Pulmonary artery Primary bronchus Pulmonary veins Grant’s Atlas of Anatomy Figure 1.29 and 1.30 20 Lungs: Applied Anatomy https://web.duke.edu/anatomy/Lab04/Lab5_preLab.html ◼ Fissures   ◼ Horizontal: Follows curvature of 4th rib Oblique: Extends from 5th ICS, MCL to 6th costal cartilage Lobes  Superior: Superior to 4 th rib, anteriorly Middle: Inferior to 4th rib, anteriorly  Inferior: Inferior to 6 th rib, posteriorly  20 Bronchopulmonary Segment Human Anatomy McKinley & O’Loughlin, 2008 Figure 25.13 ◼ ◼ ◼ Segment of the lung supplied by a tertiary bronchus Largest subdivision of a lobe Can be surgically resected 21 Functional Histology of the Lung I Branch of pulmonary A ◼ Respiratory bronchioles:  Lead to individual pulmonary lobule Terminal bronchiole  Respiratory bronchiole Branch of pulmonary V Elastic fibers Capillary beds ◼ Alveolar duct Alveoli Alveolar sac ◼ FHM 22 24.11 Branch as alveolar ducts to alveolar sacs, alveoli Branches of pulmonary arteries and pulmonary veins form capillary beds around alveoli for gas exchange Elastic fibres surround alveoli, assist in expiration Martini’s Human Anatomy and Physiology Figure 24.11 Functional Histology of the Lung II Type I cell Alveolar macrophage ◼ Type I pneumocytes form a simple squamous epithelium ◼ Type II pneumocytes secrete surfactant decrease surface tension, maintains alveolar patency ◼ Alveolar macrophages phagocytose pathogens Type II cell Alveolar macrophage Martini’s Human Anatomy and Physiology Figure 24.12 23 Blood Supply of the Lungs I Branch of pulmonary A ◼ Bronchial VA Pulmonary Circulation:  Pulmonary trunk divides into R and L pulmonary arteries, carry deoxygenated blood to alveoli Martini’s Human Anatomy and Physiology Figure 24.11 Branch of pulmonary V  Arteriole Capillaries ◼ Pulmonary veins (four) drain oxygenated blood from alveoli Bronchial Circulation:  Bronchial arteries branches of thoracic aorta supply lung parenchyma, pleura and alveoli  Bronchial veins: Drain into the azygous system Blood Supply of the Lungs II Right bronchial artery Right pulmonary artery Pulmonary trunk Right pulmonary veins Grant’s Atlas of Anatomy Figure 1.61 and 1.63 Left bronchial artery Nerve Supply of the Lungs Parasympathetic (CNX)  ▪ Bronchoconstriction ▪ Increased gland secretion Gray’s Anatomy for Students Figure 3.46 Sympathetic (from T1-5)  ▪ Bronchodilatation Lymphatic Drainage of the Lungs Right lymphatic duct Thoracic duct Bronchomediastinal trunk Bronchomediastinal trunk Superior tracheobronchial nodes Inferior tracheobronchial nodes Bronchopulmonary (hilar) nodes Bronchopulmonary (hilar) nodes Pulmonary nodes Deep Drainage Superficial Drainage Vessels follow branches of pulmonary artery and vein Visceral pleura and surface of lung Grant’s Atlas of Anatomy Figure 1.38 Boundaries of Inferior Mediastinum 1. Superiorly: Sternal plane 3. Posteriorly: Bodies of T5-T12 2. Anteriorly: Body of sternum 4. Inferiorly: Diaphragm ◼ Subdivisions:   Gray’s Anatomy for Students Figure 3.5 28  Anterior (A) Middle (B) Posterior (C) Contents of Posterior Mediastinum Thoracic duct Azygous vein Bronchus Hemiazygous vein Esophagus Descending aorta Grant’s Atlas of Anatomy Figure 1.76 and 1.77 29 Course of the Thoracic Duct Ends by draining into the junction between left internal jugular vein and left subclavian vein Thoracic duct on the left posterior mediastinum Thoracic duct crosses over at T4/5 Thoracic duct on the right posterior mediastinum Cisterna chyli Grant’s Atlas of Anatomy Figure 1.73 ◼ DEAR STUDENTS, THESE VIDEO MATERIALS ARE COPY RIGHTED PRODUCTS OF ACLANDS VIDEO ATLAS. ITS PRIVATELY OWNED COPY IM USING. IM NOT SUPPOSED TO UPLOAD PUBLICLY ! ◼ HOWEVER, THIS IS EXCLUSIVE STUDENT TEACHING AND IN A RESTRICTED ACADEMIC IT PLATFORM, SO I BEILEIVE ITS OK. ◼ PLEASE BE RESPONSIBLE, ONLY WATCH EXCLUSIVELY FOR YOUR LEARNING AND UNDERSTANDING ONCE THE WEBEX RECORDING DONE..! ◼ DON’T UPLOAD INTO INTERNET OPEN SOURCES SUCH AS YOUTUBE ◼ WE ARE PLANNING TO SUBSCRIBE FOR THIS OFFICIALLY FOR CMED-QU, SO YOU HAVE LEGAL ACCESS TO WATCH THESE MATERIAL 31 Summary ◼ ◼ ◼ ◼ ◼ Thoracic cavity is bounded by chest wall and contains lungs and mediastinum Lungs are contained in a sealed pleural cavity, lined by parietal and visceral pleurae. Lungs are organized into lobes and each lobes into segments which are accompanied (aerated) by consecutive branches of bronchial tree. Mediastinum has superior and inferior (IM) divisions. IM is divided into anterior, middle and posterior Lungs and pleurae are supplied by blood vessels, drained by lymphatics and innervated by somatic (parietal pleura) and visceral nerves. 32 Acknowledgement Moore KL, Dalley AF, Agur AMR. Moore Clinically Oriented Anatomy. Wolters Kluwer/LWW pp 108-20 This presentation contains slides from Dr 33 Mubarak Ariyo Bidmos