Anatomy Part 1 PDF

O"'Y~S~~ CARDIDUASCLIILaAR Part 1 -------------------------------Cardiovascular Mediastinum - The central compartment of the thoracic cavity. - Occupied by the mass of tissue between the 2 pulmonary...

O"'Y~S~~ CARDIDUASCLIILaAR Part 1 -------------------------------Cardiovascular Mediastinum - The central compartment of the thoracic cavity. - Occupied by the mass of tissue between the 2 pulmonary cavities - Highly mobile region (consists of hollow visceral structures united only by loose CT) Boundaries Anteriorly: Sternum & costal cartilages Superior Posteriorly: Bodies of all thoracic vertebrae medlasllnum Superiorly: Plane of thoracic inlet Inferiorly: Diaphragm Inferior medlastlnum t Subdivisions the mediastinum is divided by imaginary plane extending - From sternal angle anteriorly - to lower border of T4 vertebra posteriorly _________,,A..__ _ _ _ _____ (- Sa _ o_r _m.......~-cll-astin.....p_erl - -am--) ( Inferior + Uastlnam ) subdivided by the pericardium Anterior mediastinum Middle mediastinum Posterior mediastinum Superior mediastinum t Boundaries Anteriorly: Back of manubrium sterni Posteriorly: Upper 4 thoracic vertebrae Inferiorly: Transverse thoracic plane (extending from sternal angle to lower border of T4) On each side: Pleura & lung t Contents From anterior to posterior ' 1- Muscles Sternohyoid & sternothyroid 2- Remnants of Thymus gland 3- Vefns - Right & left brachiocephalic veins - Upper part of superior vena cava (SVC) - Arch of aorta - Brachiocephalic trunk 4-Arteries - Left common carotid artery - Left subclavian artery 5- Nerves - Vagus - Phrenic - Cardiac plexus of nerves - Trachea (anteriorly) 6- Viscera - Esophagus (posteriorly) & left recurrent laryngeal nerve \.. 7- Thoracic duct CD Dr ljoussef iJroululJ - - - - - - - - - - - - - - - - - - - - - - - - Rt. common carotid Trachea Ll common carotid Right Left IJV subclavlan vessels Left subclavian ~ DIIM ~ - - 1 vessels Superior vena cava Thymus t - ~ :::~"'="";;;;....;11.1,-_ Manubrium of sternum Left brachiocephalic vein · Right phrenic nerve - a....."! R1 - vem ·ght b rac h.1oceph a 11c Left phrenic nerve Brachiocephalic artery ~ ----. Left common carotid a. Trachea Left vagus nerve Right vagus nerve Left subclavian artery Esophagus Left recurrent laryngeal n. Right lung Thoracic duct Transverse section through superior mediastinum at the level of vertebra T3 Thymus SVC Left phrenic nerve Right phrenic n. Arch of aorta Left vagus nerve Right vagus n. Left recurrent laryngeal nerve Esophagus Thoracic duct Transverse section through superior mediastinum at the level of vertebra T4 0 - - - - - - - - - - - - - - - - - - - -- - - - - ------Cardiovascular l_ Anterior mediastinum t Boundaries Anteriorly: Body of the sternum Posteriorly: Pe ricardium ) Superiorly: Continu ous with superior med iastinum Stemo- + Inferiorly: Diaphragm pericardial ligaments + On each side: Pleura & lung t Contents - loose connective tissue, fat , lymph vessels & lymph nodes - Remnants of thymus in the upper part down to the 4th costal cartilage - Superior & inferior sterno -pericardial ligaments - Mediastinal branches of internal thoracic artery Thymus gland ' Ductless gland, formed of lymphoid tissue - It is unusual to see a distinct thymus in adult fite: Inferior part of the neck & anterior part of the superior mediastinum extends into anterior mediastinum (posterior to manubrium & anterior to fibrous pericardium) Age changes: - Well developed during fetal & early post-natal life (childhood) - Reaches its maximum size in 2 nd year after birth & remains so until puberty - Then it gradually involutes replaced by fat & fibrous tissue Arterial suppbj: Anterior intercostal & anterior mediastinal branches of internal thoracic a. Venous drainage: Left brachiocephalic, internal thoracic, & inferior thyroid veins fumphatic vessels: Parasternal, brachiocephalic, & tracheobronchial lymph nodes. ~::(''t1/;I ,_ ' - ~ - - -. !:,iiii!:i , 1\\1, ~ - /:i ,..( 1 ', Thymus gland Thymus~ - - · Thymus~. 2-yu,-dd child. ~ I. '. I J ' /.., ' ~-· '..,;. ~ ~---t- Internal thoracic artery Thymua In an ndull CD  Drljoussef ~hoululJ - - - - - - - - - - - - - - - - - - - - - - - - - Middle mediastinum J t Boundaries Anteriorly: Anterior mediastinum Posteriorly: Posterior mediastinum Superiorly: Continuous with superior mediastinum Inferiorly: Diaphragm On each side: Pleura & lung t Contents The pericardium & heart Arteries: 1- Ascending aorta 2- Pulmonary trunk dividing into right & left pulmonary arteries Veins: 1- Lower ½ of SVC & terminal part of azygos vein 2- Uppermost part of I.V.C 3- Termination of 4 pulmonary veins Bifurcation of the trachea & the 2 bronchi Phrenic nerve & pericardio-phrenic arteries on the side of pericardium [ Posterior mediastinum ] t Boundaries Anteriorly: Pericardium & diaphragm Posteriorly: Lower 8 thoracic vertebrae (TS - T12) Superiorly: Transverse thoracic plane (extending from sternal angle to lower border of T4) Inferiorly: Diaphragm On each side: The mediastinal pleura t Contents 1- Descending thoracic aorta & posterior intercostal arteries 2- Esophagus & esophageal plexus of nerves 3- Thoracic duct 4- Azygos , hemiazygos & accessory hemiazygos veins 5- Splanchnic nerves (greater, lesser and lowest) 6- Posterior mediastinal lymph nodes [D ---------------------------eardiovascular Left recurrent Esophagus laryngeal nerve Left vagus Left subclavian artery T4/5 vertebra - - Pulmonary trunk Right main bronchus main bronchus Left common carotid a. Right recurrent laryngeal n. Right common carotid a. Right subclavian a. ~ Right vagus nerve Right brachiocephalic v. Left brachiocephalic v. Left vagus nerve left recurrent laryngeal n. Pulmonary trunk CD  Dr ljoussef ihouknJ - -- - - - - - - - - - - - - - - - - - - - - - I I I Right superior intercostal vein Right vagus nerve ----1~::;,, __,..,..__ Right phrenic nerve Sympathetic trunk ~ ~ -Pericardiacophrenic vessels Azygos vein-.,.....-;,- Tracheobronchial lNs Branches of right Esophageal plexus pulmonary artery Posterior intercostal vessels Right pulmonary veins Greater splanchnic nerve Esophagus Right common carotid artery Right common carotid artery Right Internal jugular vein Right subclavian artery left subclavian artery Right subclavian vein left subclavian vein Right brachlocephalic vein Superior vena cava Accessory hemi-azygos vein Azygos vein Sympathetic trunk ,a:::"Wt-- Posterior intercostal veins lntercostal nerves Thoracic duct Hemi-azygos vein Greater splanchnic nerve lesser splanchnic nerve OJ Dr ljoussef gJroukrlJ - - - - - - - - - - - - - - - - - - - - - - - - - Pericardium Fibro-serous sac surrounding t he heart & the beginning of great vessels ' Fibrous Pericardium Outer parietal laJJer Jnner uesical laJJer Fibrous Pericardium Outer fibrous layer of the pericardium --- Surrounds pulmonary trunk, ascending aorta & superior vena cava (S.V.C.) --- Adherent to the central tendon of diaphragm & is pierced by inferior vena cava (1.V.C) Right & left surfaces Related to the corresponding phrenic nerves & lungs Posterior surface Middle 4 thoracic vertebrae (T5 - TB) being separated from them by: - Right & left main bronchi -- Esophagus & esophageal plexus of nerves - Descending thoracic aorta Anterior surface Attached to sternum by superior & inferior sterno-pericardial ligaments (Seat belts of the heart) 'Function: - Prevents transmission of cardiac pulse to the surroundings - Plays an important role in the cardiac sling mechanism Serous Pericardium Closed serous sac invaginated by heart & formed of 2 layers Parietal l~IJer: Lines fibrous pericardium & firmly attached to it llesical la1Jer: Adherent to the heart (epicardium) - The 2 layers are continuous together around roots of great vessels - Pericardial cavity: slit like potential space between the 2 layers contains pericardial fluid (15-50 ml) acting as lubricant Pericardia! sinuses Recesses of pericardial cavity at sites wh ere the visceral layer of serous becomes continuous with the parietal layer 1- The transverse sinus of pericardium 2- The oblique sinus of pericardium CD -------------------------------eardiovascular Transverse sinus Anteriorly Ascending aorta & Pulmonary trunk Left atrium Parietal layer of serous pericardium Posteriorly Left atrium & superior vena cava (separati ng it from esophagus & aorta) Reflection of visceral pericardium Superiorly to bec om e parietal perica rdium Inferiorly Opens into pericardial cavity On either - Right: 2 Rt. pulmonary veins & I.V.C. pericardial cavity sides - Left: 2 Lt. pulmonary veins Allow distension of: Ascending aorta & pulmonary trunk Allow distention of Lt. atrium Functions during 1' cardiac output during cardiac output Right atrium during atrial filling t Blood supplg - Fibrous & parietal layers: Pericardiacophrenic artery (from internal mammary artery) - Visceral layer: Coronary arteries t Nerve supplg - Fibrous & parietal layers: Phrenic nerves (sensory) - Visceral layer: Cardiac autonomic nerve plexus Visceral pericardium i_ Pericardia! cavity '\ r- Parietal / pericardium \ Air space - - - Balloon---- IT]  -· Dr ljoussef fhoukrlJ - - - - -- -- - - - - -- - - - - - - - - - -- J~ Superior ve na cava , -~ ' /!. ' ~ Arch of aorta..... Lt. pu lmonary artery pulmonary trunk 'Ij ' - C ,~ \ Peric ardiacophrenlc vessels , , Ascendi ng aorta Right phrenlc nerve tr(. ~- ~.--· -~ ,.._~..,.,,. r Fibrous Diaphragm pericardium ,-,,,n.'1111 , t 1'\llllk 0 Junction between fibrous pericardium and adventitia of great vessels ~ ~ ~'fi'c!-~~Trachea Esophagus Pulmonary artery Ascending aorta - -,.H---,,""--1 Transverse Fibrous pericardia! sinus pericardium Parietal layer Oblique Pericardia! cavity pericardia! sinus Left atrium Inferior vena cava Transverse pericardia! sinus left pulmonary veins Branches of right pulmonary artery Superior vena cava -------Oblique pericardia! sinus Finger passing through transverse ,r Cut edge of perlcardial sinus _d pericardium Pulmonary trunk Thoracic aorta OJ