Dr. Ágoston Szél Ribs, Thorax, Diaphragm Department of Anatomy, Histology and Embryology Semmelweis University 2019 1 I. Structure of the Thorax and the Ribs Mellkas - Szél 2 The thorax is a topographical „coordinate system” 2nd rib Sternal angle auscultation percussion Costal arch palpation …. Infrasternal angle 3 The thorax Superior thoracic aperture Thoracic cavity lung lung heart Inferior thoracic aperture 4 Superior thoracic Scalenus aperture medius („Thoracic outlet”) Brachial plexus Insertion of Scalenus medius Pleural cupule Scalenus Insertion of anterior Scalenus anterior Inferior trunk of brachial plexus 1st rib Subclavian artery and vein 5 Thoracic Wall Skin Connect. tiss. 6 Thoracic Wall Skin Connect. tiss. Serratus ant. 7 Thoracic Wall Skin Connect. tiss. Serratus ant. Costal groove Intercostalis externus Intercostalis internus 8 Thoracic Wall Skin Connect. tiss. Serratus ant. Intercostal vein Intercostal artery Intercostal nerve Intercostalis externus Intercostalis internus Transversus thoracis 9 Thoracic Wall Skin Connect. tiss. Serratus ant. Intercostal vein Intercostal artery Intercostal nerve Endothoracic fascia Intercostalis externus Intercostalis Parietal pleura internus Transversus thoracis 10 Thoracic Wall Skin Connect. tiss. Serratus ant. Pleural cavity (virtual space) Lung Intercostal vein Intercostal artery Intercostal nerve Endothoracic fascia Intercostalis externus Visceral pleura Intercostalis Parietal pleura internus Transversus thoracis 11 Thoracic Wall Skin Connective tissue 12 Thoracic Wall Skin Connective tissue Serratus anterior 13 Thoracic Wall Skin Connective tissue Intercostalis internus Serratus anterior Intercostalis externus 14 Thoracic Wall Skin Connective tissue Intercostalis internus Serratus anterior Transversus thoracis Endothoracic fascia Intercostal vein, Intercostalis artery and nerve externus 15 Thoracic Wall Skin Lung Visceral pleura Connective tissue Pleural cavity (virtual space) Parietal pleura Intercostalis internus Serratus anterior Transversus thoracis Endothoracic fascia Intercostal vein, Intercostalis artery and nerve externus Pleura-punction (thoracocentesis)16 Orientation of FibersV of Intercostal Muscles as seen from behind Posterior intercostal membrane Vertebral columnV Rib Internal intercostal muscle External intercostal muscle External Cartilage intercostal (v) muscle Anterior intercostal as seen membrane (v) from in front +17 II. Structure of the Diaphragm Mellkas - Szél 18 Musculo-Tendinous Separation between Thoracic Cavity and Abdominal Cavity Thorax (thoracic cavity) „Heart saddle” 5th rib (right 5th intercostal dome) space (left dome) Centrum Costal part Costal part tendineum Abdominal cavity In breathing it (abdomen) works as a piston Diaphragm Separates thoracic and Diaphrassein = barricade, abdominal cavities parition (Greek) Most important respiratory muscle Vessels and nerves traverse it Important muscle of abdominal press Development and Composition 4-5 mm thick muscular plate (striated muscle), from cervical somites Originates from septum transversum (connective tissue) Innervation: phrenic nerve (cervical plexus, C3-C4-C5) Central part is a clover- shaped (trilobed) plate of connective tissue (centrum tendineum) Serous Membranes in Connection with the Diaphragm Parietal Fibrous pericardium pericardium (serous) Parietal pleura Endothoracic fascia Parietal peritoneum Transversalis fascia The Diaphragm as Seen from Left and from Above Phrenic nerve Fibrous pericardium Thoracic aorta (Left Lung Diaphragm Removed) Syntopy of Lung, Pleura and Diaphragm Lung Parietal pleura Visceral pleura Diaphragm Liver Syntopy of Diaphragm as Seen from the Side Manubrium of Aortic arch sternum Corpus of Heart sternum Thoracic aorta Xyphoid process Abdominal aorta Topography of Main Traversing Structures Corpus of sternum Th8 Th9 Inferior vena Xyphoid cava Th10 process Esophagus Th11 Th12 Coeliac trunk L1 Thoracic / abdominal aorta The Diaphragm as Seen from Above Esophagus Inf. vena cava Thoracic aorta Centrum tendineum Pericardium Costal part Abdominal muscles Liver Stomach Diaphragm as seen from above Azygos vein Hemiazygos vein Esophagus Thoracic aorta Inferior vena cava Divisions of Diaphargm Vertebral column LUMBAR PART Lateral crus Centrum tendineum Medial crus (clover-shaped) COSTAL PART Cartilages of 6 lower ribs STERNAL PART Crus = leg, Fibrous pericardium Posterior surface of stem (Latin) xyphoid process Openings (Hiatuses) between Parts of Diaphragm Hiatus of aorta Hiatus of esophagus Hiatus of inf. vena cava Lumbocostal foramen (Bochdalek) Phrenicopericardial ligament connects Weak, triangular areas pericardium and filled out by diaphragm connective tissue Fibrous pericardium Sternocostal foramen (Larrey) Superior epigastric artery (Internal thoracic artery, from the Subclavian artery) Traversing structures Hiatus of aorta & Thoracic duct (main lymphatic duct) Hiatus of esophagus & Right and left vagus Hiatus of inf. nerves – main vena cava parasympathetic & Right phrenicoabdominal vegetative nerves branch (of phrenic nerve) – & Left sensory nerve to peritoneum phrenicoabdominal branch (of phrenic nerve) – sensory nerve to peritoneum The Diaphragm as Seen from Below Inf. vena cava STERNAL PART COSTAL PART Centrum tendineum Hiatus of esophagus Esophagus Hiatus of aorta LUMBAR PART Medial arcuate lig. Lateral arcuate lig. Abdominal muscles Medial crus (divided) * Psoas minor Psoas major *Quadratus lumborum Vertebral column The Diaphragm as Seen from Below Vena caval foramen Esophageal hiatus Common hepatic artery Aortic hiatus Vertebra L1 Vertebra L2 Vertebra L3 Parts of the Diaphragm COSTAL STERNAL PART PART RIGHT LUMBAR LEFT LUMBAR PART PART Right lateral Left lateral crus crus Right medial Left medial crus crus Lumbar vertebrae Lumbar vertebrae (L1-L4) (L1-L3) 12th rib Processus costarius L1 Arcades of the Diaphragm STERNAL Sternocostal PART foramen (Larrey) COSTAL Superior epigastric PART artery (Internal thoracic artery - Subclavian artery) Lumbocostal foramen LUMBAR (Bochdalek) PART 12th rib Processus costarius L1 Median arcuate lig. Lateral arcuate lig. (aorta-hiatus) (quadratus-arcade) Medial arcuate lig. (psoas-arcade) Traversing Structures STERNAL COSTAL PART PART Gap between medial LUMBAR crus and lateral crus PART Sympathetic trunk, Lesser splanchnic Lateral crus nerve Medial crus Gap within the right medial crus Gap within the left medial crus Azygos vein, right greater splanchnic Hemiazygos vein, left nerve greater splanchnic nerve The Diaphragm as Seen from Above Hiatus of aorta Vertebral Hiatus of LUMBAR PART column esophagus Medial crus Hiatus of inf. vena cava Lateral crus Centrum tendineum COSTAL PART Pericardium fibrosum STERNAL PART The Diaphragm as Seen from Below STERNAL PART COSTAL PART Th11 Centrum tendineum L1 LUMBAR PART 12th rib Processus L3 costarius L1 Medial crus L5 Lateral crus III. The Mechanism of Breathing Mellkas - Szél 39 Inspiration (inhalation) Expiration (exhalation) ribs elevate, transveral ribs sink, transversal diameter increases diameter decreases costal arch: obtuse angle 40 costal arch: acute angle Joints of ribs Joint of head of rib Inhalation: the sternum elevates Inhalation: the rib The axis slants elevates backwards and sidewards Sternocostal joint Costotransversal joint +41 Transversal (l-l) diameter of thoracic cage increases Movement of bucket handle Level of ribs elevates Vertebra The axis slants Sternum sidewards Rib 42 Sagittal (a-p) diameter of thoracic cage increases Movement of arm of well Axis slants backwards Sternum Sternum and costal cartilage elevates Rib 43 Combination of the two movements (l-l, a-p) Volume of thorax increases Sternum and costal cartilage Level of ribs elevates elevates 44 The Bayle’s scheme VertebralV column Elevation of ribs - inhalation Intercostalis externus contracts Resting phase – pause in respirations Depression of ribs - V exhalation Intercostalis internus contracts 45 Upon deep inspiration the dorsal kyphosis flattens •Erector spinae muscle contracts •The dorsal vertebral column becomes straight •The volume of thorax (in length) increases Movement of piano harmonica (accordion) Expiration Inspiration +46 The diaphragm is the most important breathing muscle Inspiration Expiration Costo-phrenic angle: larger Costo-phrenic angle: smaller Thoracic respiration (inspiration) •Ribs elevate, dorsal kyphosis straightens •Thorax-volumen (in all directions) increases Abdominal respiration (inspiration) •Diaphragm descends („piston”) •Abdominal muscles relax (belly rounds) •Thorax volumen (longitudinal) increases 48 IV. Further information Forced breathing Mellkas - Szél 49 abdominal respiration thoracic respiration inspiration expiration expiration inspiration abdominal wall thoracic wall retracts or bulges rises or falls back 50 Normal respiration (intercostal muscles, diaphragm) Forced respiration (physical exercise, degeneration of thoracic joints, etc.) Forced inspiration Forced expiration thoracic, cervical abdominal muscles, muscles, posterior posterior inferior superior serratus serratus, quadratus lumborum Asphyxia (dyspnoe), suffocation e.g. alien body, e.g. emphysema, stenosis of trachea bronchial asthma 51 Serratus post. Auxiliary respiratory muscles sup. (elevates the upper ribs) Levator costarum (elevates the ribs) Serratus post. Quadratus lumborum inf. (depresses (depresses the 12th the lower ribs) rib) 52 Auxiliary respiratory muscles Nasal muscles (nostrils widen) Scalenus anterior, medius et posterior (elevates upper ribs) Sternocleidomastoideus (elevates