thorax - yomna 3.pdf

Thorax a region of the body located between the root of the neck and abdomen It is bounded anteriorly by sternum and costal cartilage Bounded posteriorly by the thoracic part of the vertebral column or 12 vertebrae Laterally 12 pairs of ribs and intercostal spaces Superiorly by s...

Thorax a region of the body located between the root of the neck and abdomen It is bounded anteriorly by sternum and costal cartilage Bounded posteriorly by the thoracic part of the vertebral column or 12 vertebrae Laterally 12 pairs of ribs and intercostal spaces Superiorly by supra plural membrane Inferiorly by the diaphragm Thoracic wall consists of two compartments 1. boney compartment - thoracic cage 2. soft tissue - intercostal muscles and intercostal vascular bundle The thoracic cage Functions of the thoracic cage: protect the heart, lungs, pericardium, pleura Provides attachment for muscles: abdominal muscles, thoracic muscles, muscles of upper limb, muscles of the back The sternum contains a large amount of bone marrow for production of blood cells Thoracic cage anterior wall is formed by the sternum and costal cartilage Lateral Wall formed by 12 pairs of ribs with intercostal space between them posterior wall is formed by 12 thoracic vertebrae, intercoastal neurovascular bundle: Arteries, veins, lymphatic vessels, nerves The superior opening is known as the thoracic inlet/outlet because it’s responsible for both substances, leaving and entering Boundaries of the thoracic inlet (outlet): Parts: manubrium & body Bounded anteriorly by upper border of manubrium bounded posteriorly by first thoracic vertebrae bounded laterally by first thoracic rib Thoracic outlet syndrome: three structures are compressed: 1. Lower trunk of the brachial plexus (vein) ○ Symptoms include severe pain, numbness loss of sensation, pain along the medial aspect of little finger, hand and forearm 2. Subclavian artery ○ causes ischaemia of upper limbs and necrosis ○ ischaemia is insufficient blood supply to the tissue ○ the patient lasts six hours known as golden hours ○ skin turns black ○ otherwise necrosis is necessary, which is amputation of the limb 3. Subclavian vein, ○ causes stagnation (blocking) and swelling of upper limbs causes of thoracic outlet syndrome 1. cervical rib ○ An abnormal additional rib, grown from the transverse process of the seventh cervical vertebrae ○ It could be unilateral or bilateral ○.5% of the world population have it ○ 50% of the.5% are bilateral and the other 50% is unilateral ○ Treatment: good history investigation, then CT scan of the neck. Once the cervical rib is found it’s treated by surgical treatment or surgical removal. 2. Pancoast tumour ○ cancer affecting the apex (copula = apex + pleural membrane) of the lung ○ usually secondary carcinoma ○ treatment is radiotherapy and chemotherapy The anterior wall of the thoracic cage 1. sternum 2. Costal cartilage costo meaning ribs/to the ribs sternum flat bone Cartilagineous in development Located in the midline of the anterior wall of the thoracic cage Three parts: ○ superior - manubrium ○ middle - body of sternum (largest) ○ inferior - xiphoid process (smallest) attach laterally to the coastal cartilage Manubrium of the sternum superior part of sternum Angular notch located at the upper border of manubrium, also known as supra sternal notch Lateral border provides articulation with clavicle to form sternoclavicular joint (synovial joint, plane) Articulate with the first rib to form first sternocostal joint (primary cartilaginous) Articulate with the upper half of second rib to form second sternocostal joint (synovial joint, plane) Sternal angle (manubriosternal joint, Louis angle) secondary cartilaginous joint formed by articulation between manubrium and body of sternum Located at the second rib Located at the second coastal cartilage Between T4 and T5 structures found in the sternal angle that could be damaged in case of accident 1. beginning and end of the arch of aorta 2. Bifurcation of trachea intro right and left main bronchus 3. bifurcation of pulmonary artery into the right and left trunk 4. Oesophagus in the midline at sternal angle 5. Thoracic duct at the midline, 45 cm in length 6. Cardiac plexus 7. Azygous vein into superior vena cava 8. Left recurrent laryngeal nerve, passing around ligamental arteriose Function of Manubrium: protection of arch or aorta Body of sternum Flat in shape protects the heart Articulate, laterally with the lower half of 2nd rib to 7th forming sternocostal joint - synovial joint Articulates superiorly with the manubrium to form sternal angle - secondary cartilaginous Articulates inferiorly with the xiphoid process to form xiphisternal joint Functions of body of sternum protects the heart Contains a large amount of bone marrow clinical correlation of the body of sternum aspiration of bone marrow by wide broad needle sternotomy : vertical surgical incision through the sternum during open heart surgery Xiphoid process small triangular part of the sternum No articulation laterally or inferiorly articulates superiorly with the body of the sternum to form xiphisternal joint level T9 - secondary cartilaginous located at the midline function of the xiphoid process protection if oesophagus attachment for muscles Costal cartilage it provides flexibility to prevent fracture of ribs during trauma 1-7 true costal cartilage because they attach directly to the lateral border of sternum 8-9-10 false attached to the sternum indirectly 8 attached to 7, 9 attached to 8, 10 attached to 9 11&12 are floating Costochondral joint (primary cartilaginous): between ribs and costal cartilage ribs 2 to 7 attached to sternum Sternocostal joint: between sternum and costal cartilage from 2nd to 7th synovial while first rib is primary cartilaginous Interchondral joint: between ribs and 7-10 costal cartilage primary cartilaginous Lateral wall of the thoracic cage 1. 12 pairs of ribs 2. Intercostal spaces: filled by soft tissues, containing muscle, nerves, arteries, veins Ribs 12 pairs, 12 on the right, and 12 on the left ribs have two classifications 1. according to the attachment of the ribs to the sternum ○ contain three groups: ○ 1. True ribs 1-7 ○ 2. false ribs 8-10 ○ 3. floating ribs 11-12 ○ clinical correlation: the rib least likely to develop fracture due to trauma is the first because it’s covered by the clavicle and 11th and 12th because they’re floating 2. Classification according to typical or atypical ribs ○ typical ribs 3-9 ○ atypical ribs 1-2 & 10-12 typical ribs criteria: 1. presence of head ○ located posteriorly ○ Head containing two articular facets inferior to allow articulation with the corresponding thoracic vertebrae and superior for the above thoracic vertebrae ○ The joint is called costovertebral joint - synovial, plane 2. presence of neck ○ The neck is attached to the transverse process of the corresponding thoracic vertebrae by ligament called costotransverse ligament ○ another ligament superior costotransverse ligament extends from the neck to attach to the thoracic vertebrae above 3. Presence of Tubercle ○ contains two facets ○ Medial to be articulated to the transverse process of the corresponding thoracic vertebrae  ○ lateral attached to the transverse process of the corresponding thoracic vertebrae to by lateral costotransverse ligament 4. presence of shaft/body ○ flat ○ directed from one side to the other 5. angle of rib (weakest area) ○ weak because change in shape causes change in direction 6. presence of the coastal groove ○ contains VAN ○ intercostal vein, intercostal artery, intercostal nerve ○ vein is hidden the most to avoid dyspnoea - vein goes from tissue to heart ○ needle is inserted at the upper border of rib atypical ribs 1. 1st rib ○ very short and wide ○ Head contains one articular facet ○ Presence of additional tubercle known as scalene tubercle ○ Additional grooves for subclavian vein and artery 2. 2nd rib ○ very narrow ○ Very long ○ Additional tubercle called serratus anterior muscle 3. 10th rib ○ Head contains one articular facet ○ No neck ○ No tubercle 4. 11th rib ○ Head contains one articular facet ○ no neck ○ no angle ○ no tubercle ○ very shallow coastal groove 5. 12th rib ○ one articular facet ○ No neck ○ no tubercle ○ no angle ○ no costal groove thoracic cage during inspiration: increase of vertical dimension to allow for expansion of lungs anterior and posterior dimension increase only by movement of anterior wall thoracic cage expands outward clinical correlation of ribs: fracture of ribs causes: 1. paradoxical respiration  ○ caused by multiple fracture of ribs ○ the thoracic wall goes inward during respiration due to multiple fracture of ribs ○ leads to death 2. rupture of parietal pleura ○ caused by sharp broken end poking the parietal pleura ○ leads to: ○ allowing air in - pneumothorax ○ allowing blood/fluid in - haemothorax ○ allowing air and blood in - hemopneumothorax ○ allowing puss in - empyema 3. fracture of left 9-10-11 ribs ○ laceration of spleen 4. fracture of right 9-10-11 ribs ○ laceration of liver the posterior wall of thoracic cage: formed by 12 thoracic vertebrae parts of the vertebrae: anterior - body of vertebrae posterior - spinous process middle - vertebral foramen which has passage of spinal cord laterally - left and right transverse process region between body and transverse process - pedicle region between transverse process and spinous process - lamina in case of surgical operation: lamina is removed in laminectomy each vertebrae has superior articular process to be articulated with the vertebrae above each vertebrae has inferior articular process to be articulated with the vertebrae below thoracic vertebrae criteria: costal facets located on each side of the body: 2 superior costal facets: articulated with the head of the corresponding rib 2 inferior costal facets: articulated with the head of rib below at the tip of transverse process are 2 costal facets to be articulated to the tubercle of rib 6 total facets body of thoracic vertebrae is heart shaped body of lumbar vertebrae is kidney shaped typical thoracic vertebrae 2-10 atypical thoracic vertebrae 1-11-12 1 has one articular facet 11 has one articular facet 12 has one articular facet 4 structures crossing the neck of the first rib, medial to lateral: 1. sympathetic chain 2. First posterior intercostal vein 3. Superior intercostal artery - provides arterial blood supply to the intercostal spaces 4. First thoracic nerve Suprapleural membrane: 1. A dense facial layer called Sibson’s facial 2. attached to the internal surface of the first rib 3. attached to the internal surface of the first costal cartilage 4. attached to the transverse process of the 7th cervical vertebrae 5. attached to the parietal pleura inferiorly 6. attached to the mediastinal pleura medially copulla covers the apex of the lung functions of the suprapleural membrane: 1. Act as a roof of thoracic cavity  2. Provide separation between root of neck and thoracic cavity 3. Provides rigidity of the thoracic inlet 4. Provides protection of parietal pleura of the lung 5. Prevents movement of structures of the neck, up-and-down during respiration Complication if damaged: Leads to pneumothorax - entrance of gas mediastinum: Vertical space between the right and left lung divided by an imaginary line based on the sternal angle into: 1. superior mediastinum ○ wide but not divided 2. inferior mediastinum ○ divided into anterior, posterior and middle mediastinum by the presence of the heart ○ heart located in the middle mediastinum intercostal muscles: divided into 3 layers: 1. external layer ○ formed by external intercostal muscles ○ Inspiratory muscles 2. Middle layer ○ formed by internal intercostal muscles ○ expiratory muscles 3. internal layer ○ formed by innermost intercostal muscles each striated muscle has: origin, insertion, innervation and action external intercostal muscles: external layer origin: from inferior border of rib above insertion: superior border of rib below direction of fibres: downward forward replaced by anterior intercostal membrane function during inspiration extension: fills the place between superior costotransverse ligament posteriorly till the level of costochondral junction anteriorly space between costochondral junction and sternocostal joint filled by anterior intercostal membrane inspiratory muscles: thorax elevates superiorly, first rib is fixed by scalene muscle, ribs 2-12 elevate superiorly expiratory muscles: thorax goes downward, twelfth rib is fixed, ribs 1-11 descend inferiorly internal intercostal muscles: middle layer formed by internal intercostal layer do not extend more than one intercostal space origin: inferior border of rib above insertion: superior border of rib below direction of fibres: downward backward replaced by posterior intercostal membrane function during expiration extension: from sternocostal joint posteriorly till angle of rib between the angle of rib and vertebral column replaced by posterior intercostal membrane VAN present between internal and innermost layers innermost intercostal muscles inner layer divided into 3 groups 1. Anterior group - transversus thoracis - sternocostalis ○ Fibre is a fan shaped ○ fibres extends into more than one space 2. lateral group - innermost intercostal muscle 3. posterior group - subcostal muscle action during expiration innervation of the intercostal spaces Intercostal nerve: originates from anterior primary rami and takes fibres from posterior rami passing through intercostal space above the artery ○ divided into three branches i. collateral ii. lateral cutaneous iii. anterior cutaneous 1. Collateral innervation ○ intercostal muscles ○ parietal pleura of lungs ○ periosteum of ribs (thin outer layer) 2. Lateral cutaneous (skin only) ○ anterior branch: innervates the skin lateral to the thorax ○ Posterior branch: innervates the skin posterior to the thorax 3. anterior cutaneous ○ medial ○ lateral the lower five intercostal nerves provide innervation for anterior abdominal wall any skin or muscle in upper limb innervated by brachial plexus except small area located at the upper part of medial aspect of the upper arm intercostobrachial nerve coming from T2 The second intercostal nerve: the blood supply of the posterior intercostal spaces: arterial blood supply 11 posterior intercostal spaces posterior lower 9 intercostal spaces receives blood supply from branches coming from descending thoracic aorta 1st and 2nd intercostal spaces receives arterial blood supply from superior intercostal artery which originates from costocervical artery (trunk) which originates from second part of subclavian artery subclavian artery on left side originates directly from arch of aorta while on the right side originates from brachiocephalic artery the blood supply of the anterior intercostal spaces: arterial blood supply internal thoracic artery upper 6 intercostal spaces receive branches from internal thoracic artery the 7-8-9 receive blood supply from musculophrenic artery the musculophrenic artery originates from internal thoracic artery no arterial blood supply for 10-11 intercostal spaces anteriorly internal thoracic artery right and left provides anterior blood supply to human being body from the clavicle until the umbilicus used for coronary artery bypass graft CABG internal mammary artery originates from first part of subclavian artery passing along inner surface of anterior wall of thoracic cavity located 1cm lateral to the lateral border of sternum branches of internal thoracic artery: 1. intercostal branches 2. musculophrenic artery 3. superior epigastric artery 4. pericardiacophrenic artery 5. perforated arteries ○ most important are 2,3,4 intercostal spaces ○ very large in size because they provide blood supply to the breast ○ mammary artery ○ only provides 20% of blood supply clinical correlation of internal thoracic artery coronary artery bypass graft CABG venous drainage of thoracic wall venous drainage of anterior thoracic wall into: 1. internal thoracic vein 1-6 intercostal spaces  2. musculophrenic vein 7-9 intercostal spaces internal thoracic vein drains venous blood of upper 6 anterior intercostal spaces which ends in the brachiocephalic vein on each side left brachiocephalic vein receives the left internal thoracic vein right brachiocephalic vein receives the right internal thoracic vein musculophrenic vein one of the tributaries of internal thoracic vein drains into internal thoracic vein right brachiocephalic vein formed by union between right subclavian vein and right internal jugular vein left brachiocephalic vein formed by union between left subclavian vein and left internal jugular vein superior vena cava formed by union between right and left brachiocephalic veins largest vein after inferior vena cava collects the whole deoxygenated blood of the upper part of body through left and right brachiocephalic veins deoxygenated blood of the lower body comes through inferior vena cava deoxygenated blood is collected into right atrium venous drainage of posterior thoracic wall: venous drainage of posterior lower 8 intercostal spaces at the right side of thorax drain into azygos vein venous drainage of posterior lower 8 intercostal spaces at the left side of thorax drain into hemiazygos vein venous drainage of posterior 1st intercostal space on the right side drains mainly into right brachiocephalic vein and on the left side drains into left brachiocephalic vein small percentage drain into vertebral vein venous drainage of posterior 2nd and 3rd intercostal spaces: they union to form superior intercostal vein on each side right superior intercostal vein drains into right costocervical vein right costocervical vein drains into right subclavian vein left superior intercostal vein drain into the left costocervical vein left costocervical vein drains into the left subclavian vein lymphatic drainage of thoracic wall lymphatic drainage of anterior thoracic wall drains into anterior group of the axillary lymph node group lymphatic drainage of posterior thoracic wall drains into posterior group of the axillary lymph node group lymphatic drainage of anterior intercostal spaces parasternal lymph node group lymphatic drainage of posterior intercostal spaces posterior lymph node group clinical correlation of thoracic wall 1. thoracic outlet syndrome - caused by cervical rib or pancoast tumour 2. fracture of ribs: a. causes paradoxical respiration -> flail chest, inward movement of thoracic wall b. ribs left 9,10,11 causes laceration of spleen c. ribs right 9,10,11 cause laceration of liver 3. pneumothorax - air in the pleural cavity 4. hemothorax - blood in the pleural cavity 5. hemopneumothorax - air and blood in the pleural cavity 6. hydropneumothorax - entrance of liquid that isn’t blood into the pleural cavity 7. empyema - pus in the pleural cavity 8. sternotomy - vertical surgical incision through the sternum during open heart surgery 9. aspiration of bone marrow from sternum - used for transplantation of bone marrow 10. thoracotomy - surgical incision through the intercostal space to reach one of the intrathoracic organs 11. pneumonectomy - surgical removal of the lung through the thoracotomy 12. lobectomy - surgical removal of lung lobe 13. thoracostomy - insertion of chest tube to treat pneumothorax, hemothorax, hemopneumothorax, empyema a. inserted at midclavicular line into the second intercostal space b. inserted into anterior axillary line into any intercostal space but mainly the fourth or second intercostal space 14. 4 vertical imaginary lines 1. midclavicular line from midpoint of clavicle 2. anterior axillary line from anterior aspect of axela 3. mid axillary line from mid point of axela 4. posterior axillary line from posterior aspect of axela layers of the skin from outside to the inside: skin - superficial fascia - deep fascia - external intercostal muscles - internal intercostal muscles - innermost intercostal muscles - thoracic membrane 3 areas with no deep fascia: face, lower part of abdomen, penis diaphragm a fibro muscular structure very important respiratory muscle made of fibro muscular tissues separates thoracic cavity from abdominal cavity acts as a floor of thoracic cavity and roof of abdominal cavity has 2 domes: right and left domes right dome covers the liver left dome covers the spleen Functions of the diaphragm: 1. inspiratory functions - pushes abdominal organs inferiorly and increases vertical dimensions of the thoracic cavity to allow lungs to expand 2. expiratory functions - assist lung in evacuating the air 3. straining of abdomen - compresses abdomen to increase the intra abdominal pressure needed for micturition/urination, defecation, parturition/birth 4. guarding of gastroesophageal junction 5. assist venous drainage of inferior vena cava anatomical structure of diaphragm the diaphragm consists of: 1. central tendon: ○ strong fibrous tissue structure connected to the fibrous pericardium of the heart ○ supports the fibrous pericardium and the diaphragm ○ located at the midline level of xiphisternal joint 2. peripheral muscular part: ○ consists of: i. vertebral part ii. costal part iii. sternal part peripheral muscular part: 1. Vertebral part a. crura i. right crus - originates from the sides of upper 3 lumbar vertebrae and their intervertebral disks ii. left crus - originates from the first and second lumbar vertebrae and their intervertebral disks b. arcuate ligament i. medial arcuate ligament - formed by the condensation of the fascia covering the psoas major muscle ii. lateral arcuate ligament - formed by the condensation of the fascia covering the quadratus lumbural muscle iii. median arcuate ligament - formed by mixtures of fibres coming from right crus and left crus 2. Costal Part - muscular fibre that originates from lower 6 ribs and costal cartilage 3. Sternal part - originates from xiphoid process openings of diaphragm 1. caval opening ○ level T8 ○ located within the right crus ○ provides passage for inferior vena cava and right phrenic nerve 2. esophageal opening  ○ level T10 at 6th costal cartilage ○ located within the left crus ○ surrounded by fibres coming from the right crus ○ provides passage for oesophagus and vagus nerve (left and right vagi) ○ contains esophageal branches of left gastric artery and left gastric vein ○ level at which thoracic oesophagus is converted into abdominal oesophagus is T10 ○ level at which inferior vena cava passing from the thorax to the abdomen is T10 3. Aortic opening ○ level T12 at the midline ○ provides passage for aorta ○ thoracic aorta becomes abdominal aorta at T12 ○ provides passage for thoracic duct ○ provides passage for azygos vein structures passing through the diaphragm: 1. left gastric nerve 2. sympathetic chain 3. hemiazygos vein 4. subcostal artery, vein, nerve 5. splanchnic nerve 6. extra peritoneal lymphatic vessels 7. neurovascular bundle from intercostal space 6-11 8. superior epigastric vessel Hiccup - involuntary, spasmolic contraction of the diaphragm immediately associated with the closure of the glottis, therefore leads to the secretion of air vagus nerve (10th cranial nerve) is compressed blood supply of the diaphragm arterial blood supply: costal and sternal part receive through the lower five intercoastal arteries and subcostal arteries the inferior phrenic arteries coming from the abdominal aorta gives the right and left crus The superior phrenic arteries coming from the thoracic aorta, gives the remaining part of the diaphragm musclophrenic artery originating from internothoracic artery, gives the remaining part pericardiacophrenic artery venous drainage intercostal vein subcostal vein inferior phrenic vein superior phrenic vein musculophrenic nerve pericardiacophrenic vein innervation of the diaphragm motor innervation coming from phrenic nerve (originates from C3,4,5) sensory innervation why is the pain referred from the centre of chest to the tip of shoulder during myocardial lymphaction - the tip of the shoulders sensory innervation is C4 and the root of the phrenic nerve is C3, C4, C5 sensation of diaphragm phrenic nerve lower intercostal nerves clinical correlation of phrenic nerve phrenic nerve leads to referred pain damage of phrenic nerve causing paralysis of diaphragm clinical correlation of diaphragm damage of phrenic nerve causes paralysis of diaphragm the diaphragm elevates superiorly compressing the lung causing difficulty of breathing and respiration hiatus hernia 2 types according to the cause: 1. congenital - failure of the formation of the pleuroperitoneal membrane ○ bochdalek foramen is formed - which is the dilated foramen of the esophageal opening due to the defect of pleuroperitoneal membrane 2. acquired 2 types according to the movement of gastroesophageal junction: 1. sliding hiatus hernia - transposition of the gastroesophageal junction from the abdominal cavity to the thoracic cavity leading to the erosion of walls of the oesophagus because of HCl, leads to esophagitis and CA oesophagus ○ symptoms include: heartburn, bleeding 2. rolling hiatus hernia - the fundus of the stomach elevates superiorly and compresses the oesophagus, causes dysphagia (inability to swallow) treatment: anti heartburn, cold milk, quit caffeine then repair hernia surgically thoracic cavity roof of the thoracic cavity formed by suprapleural membrane floor is the diaphragm bounded anteriorly by anterior thoracic wall bounded anteriorly by posterior thoracic wall thoracic cavity divided into left and right cavities left cavity containing left lung right cavity containing right lung between them a vertical space know as mediastinum is found the mediastinum is divided into superior and inferior by an imaginary line at the level of the sternal angle anteriorly, and between T4&T5 posteriorly level of sternal angle acts as a floor for superior mediastinum and roof for inferior mediastinum inferior mediastinum is divided into anterior, middle and posterior heart surrounded by the pericardium is found in the middle mediastinum the superior mediastinum the space bounded anteriorly by manubrium posteriorly by the the upper four thoracic vertebrae bounded laterally by the lungs and pleura bounded inferiorly by the imaginary line found at the sternal angle continues inferiorly with the posterior and anterior mediastinum contents of the superior mediastinum: 4 structures: 1. trachea 2. oesophagus 3. thoracic duct 4. thymus (upper part) 4 arteries: 5. arch of aorta 6. brachiocephalic artery 7. left common carotid artery 8. left subclavian artery 4 veins: 9. brachiocephalic vein 10. superior vena cava 11. arch of azygous vein 12. left superior intercostal vein 4 nerves 13. phrenic nerve 14. vagus nerve 15. recurrent laryngeal nerve 16. superficial cardiac plexus 1.Trachea fibro muscular cartilaginous tube measuring about 10-12 cm in length diameter in adult 2cm diameter in infant 3mm begins at the level of cricoid cartilage / C6 as a direct continuation of the larynx has a cervical part (passing though the neck) and a thoracic part (passing through the thorax) to end at the sternal angle by bifurcation into left and right main bronchi point of bifurcation is called carina located anterior to the oesophagus between them is a groove called tracheoesophageal groove the tracheoesophageal groove allows for the passage of recurrent laryngeal nerve clinical correlation: failure of separation of wall between trachea and oesophagus a hole forms known as tracheoesophageal fistula during breastfeeding, milk goes into the trachea to the lung instead of oesophagus causes infections and sound when breathing formed by smooth muscle called trachealis muscle containing fibrous tissue between muscle and cartilage tracheal rings are cartilaginous in consistency 15-20 tracheal rings deficient/empty posteriorly to allow the passage of food through the oesophagus functions of tracheal rings: maintain the patency of the tube of trachea functions of trachea: passage of air from upper respiratory tract to the lower respiratory tract blood supply to the trachea arterial blood supply inferior thyroid artery bronchial artery venous drainage inferior thyroid vein bronchial vein lymphatic drainage: pre tracheal lymphatic node para tracheal lymphatic node deep cervical lymph node 2.oesophagus a muscular tube measuring about 25 cm in length Begins as a direct continuation of the pharynx at level C6/cricoid cartilage to end at the gastro-oesophageal junction(T11)/Cardiac region of the stomach Located at level T10 Passes through three regions/parts 1. Cervical oesophagus - passsing through neck 2. Thoracic oesophagus - passing through thoracic cavity 3. Abdominal oesophagus at T10 ends at T11 Function: transport/transmission of food from the pharynx to the stomach Located immediately behind the trachea passing through superior and posterior mediastinum blood supply of the cervical esophagus areterial: inferior thyroid artery (from thyrocervical artery from first part of subclavian artery) venous: inferior thyroid vein which drains into left brachiocephalic vein on left side lymphatic: deep cervical lymph node blood supply of the thoracic esophagus arterial: esophageal branches coming from descending thoracic aorta bronchial arteries venous: drains into bronchial vein and azygous system lymphatic: posterior mediastinal lymph node blood supply of the abdominal esophagus arterial: left gastric artery venous: into left gastric vein lymphatic: serial lymph node group paraaortic lymph node Innervation parasympathetic for cervical - from recurrent laryngeal nerve parasympathetic for remaining part - from the vagus nerve sympathetic - from the lower cervical ganglia and thoracic ganglia clinical correlation sliding hernia - erosion of oesophagus, esophagitis, bleeding on oesophagus, heartburn rolling hernia - fundus of stomach goes behind it and compresses it leading to dysphagia esophageal varices - rupture of esophageal vein due to liver cirrhosis which is caused mainly by schistosoma or alcohol hematemesis - vomiting blood CA oesophagus 3. Thoracic Duct largest lymphatic duct in the body about 45 cm in length Passing through both superior and posterior mediastinum Formed within the abdominal cavity as cisterna chyil Passes from the thoracic cavity to the abdominal cavity at T12 level of aortic opening of the diaphragm Function: collect lymphatic drainage of the lower part of the body and upper left quadrant all except the upper right quadrant: right head and neck, right thoracic cavity, right upper limb Fate: ends into the junction between the left internal jugular vein, and left subclavian vein giving the brachiocephalic vein 4.Thymus a Glandular lymphatic organ Consists of right lobe and left lobe very large during childhood and regresses in adulthood Passes through superior and anterior mediastinum Function: Produces T-lymphocytes, immunological function Arterial blood supply: Inferior thyroid artery Internal thoracic artery venous drainage: Inferior thyroid vein Internal thoracic vein Lymphatic drainage: parasternal lymph node para aortic lymph node Innervation: sympathetic and parasympathetic 5.Aortic Arch formed by the direct continuation of ascending aorta beginning and end of arch of aorta located at sternal angle arch of aorta located in superior mediastinum protected by manubrium provides origins for 3 branches from right to left: brachiocephalic artery left common carotid artery left subclavian artery right common artery and right subclavian artery originate from brachiocephalic artery which originates from arch of aorta clinical correlation: thyroidea ima: an extra 4th artery originating from brachiocephalic artery or directly from arch of aorta rupture of aorta due to trauma causes immediate death 6.brachiocephalic artery first and largest branch of arch of aorta located in superior mediastinum 2 branches:  right common carotid artery right subclavian artery 7. left common carotid artery second branch of arch of aorta part of superior mediastinum ascending superiorly to give blood supply to brain, face, head and neck at level C4/thyroid cartilage it bifurcates into: internal carotid artery: provides blood supply to brain external carotid artery: provides blood supply to head & neck adams apple 8.left subclavian artery 3 parts first part: vertebral artery internal thoracic / mammary artery thyrocervical artery second part: costocervical artery 9.brachiocephalic vein formed by union between internal jugular vein and subclavian vein behind sternoclavicular joint on each side 10. Superior vena cava formed by union between right and left brachiocephalic vein at lower border of first costal cartilage then it penetrates the fibrous pericardium at the lower border of second costal cartilage then enters the right atrium at lower border of third costal cartilage located within superior mediastinum collects the whole deoxygenated blood of upper part of the body 11. Arch of azygos vein passes through superior and posterior mediastinum formed by union between right ascending lumbar vein and right subcostal vein collects venous drainage from right lower 8 posterior intercostal veins and right superior intercostal vein and some organs of the right side of the thoracic cavity passes through posterior mediastinum and forms an arch into the superior mediastinum enters the superior vena cava at level of sternal angle receives the hemiazygos vein and accessory azygos vein 12. left superior intercostal vein formed by union of left posterior second and third intercostal veins which drains into left brachiocephalic vein 13. vagus nerve tenth cranial nerve carrying the parasympathetic innervation for the viscera of neck, thorax and abdomen clinical correlation: vagotomy provides branch called recurrent laryngeal nerve 14. recurrent laryngeal nerve originates from right and left vagus nerve left - passing around ligamentum arteriosum right - passing around right subclavian artery clinical correlation: tumour developed compresses it causing change in voice can be damaged during ligation of thyroid artery 15. phrenic nerve right & left consists of C3, C4, C5 right phrenic nerve passes through right dome of diaphragm through caval opening left phrenic nerve passes through the left dome of diaphragm and penetrates it provides motor innervation of diaphragm only sensory innervation of diaphragm coming from phrenic and clinical correlation:damage causes paralysis of diaphragm, ascending superiorly compressing inferior part of lungs 16. superficial cardiac plexuses junction between deep and superior located at sternal angle superficial located at superior mediastinum deep located at middle mediastinum Anterior mediastinum: small space located between sternum and fibrous pericardium bounded anteriorly by body of sternum and posteriorly by the fibrous pericardium contents coming from superior mediastinum: 1. thymus 2. sternopericardial ligament - ligament connecting sternum and pericardium 3. tributaries of internal thoracic vein 4. branches of internal thoracic artery 5. fat and lymphatic vessels posterior mediastinum small space located posterior to the heart and pericardium and anterior to the thoracic vertebrae T5-T12 Contents: 1. oesophagus 2. thoracic duct 3. azygos vein 4. hemiazygos vein 5. descending thoracic aorta 6. vagus nerve 7. thoracic sympathetic chain Hemiazygos vein formed by union of left ascending lumbar vein and left subcostal vein receives the left 8 lower intercostal veins posteriorly drains into the azygos vein collecting some structures located on the left side Descending thoracic aorta content of posterior mediastinum direct continuation of the arch of aorta after the level of sternal angle the beginning is the sternal angle to end at the level of T12 when entering the aortic opening of diaphragm to be converted into abdominal aorta branches: lower 9 posterior intercostal arteries subcostal arteries bronchial arteries - branches provided to lung and trachea, bronchi esophageal arteries - provides branches to the thoracic oesophagus superior phrenic arteries - provides arterial blood supply to diaphragm pericardial arteries - arterial blood supply to the pericardium of the heart the middle mediastinum bounded anteriorly by anterior mediastinum bounded posteriorly by posterior mediastinum bounded superiorly by superior mediastinum surrounded by the pericardium contents: 1. pericardium 2. heart 3. roots of great vessels (ascending aorta, pulmonary trunk,superior and inferior vena cava, pulmonary veins) 4. root of lungs 5. deep cardiac plexus 6. phrenic nerve (C3,C4,C5) The pericardium: located in the middle mediastinum surrounds the heart and roots of great vessels consists of 2 compartments: 1. fibrous pericardium 2. serous pericardium a. parietal layer (outer) b. visceral layer (attached to the heart) the space between parietal layer and visceral layer is pericardial cavity pericardial cavity is filled with pericardial fluid about 50 ml to act as a lubricant and prevent friction of both layers during contraction Functions: protection of heart maintenance of position of heart prevents massive movement of heart during contractions keeping the great vessels open provide lubrication to prevent friction prevent adhesion of the heart and neighbouring structures attachments of the pericardium attached anteriorly to the sternum by sternopericardial ligament attached inferiorly to the diaphragm by the central tendon attached to the root of great vessels by adventitia touches the phrenic nerve to allow for innervation of the fibrous and parietal The fibrous pericardium very strong fibrous tissue structure surrounding the heart externall acts as an external layer of the pericardium attached to the sternum, central tendon of the heart and adventitia of great vessels innervation of thr fibrous and parietal: by phrenic nerve blood supply of the fibrous and parietal: internal thoracic artery 1 musculophrenic artery 2 pericardiacophrenic artery (branches) receives branches from bronchial arteries: 3 bronchial branches 4 pericardial branches of descending thoracic aorta venous drainage of the fibrous and parietal: internal thoracic vein innervation of visceral: autonomic, sympathetic, parasympathetic making it insensitive to pain lymphatic drainage parasternal lymph node parietal layer is very sensitive to the pain visceral layer is known as the epicardium inner layer is the endocardium, responsible for production of valves of the heart embryo logically usually develops infection known as endocarditis from streptococcal bacteria formed during chronic tonsillitis chronic tonsillitis - a child having tonsillitis more than 3 times per month treated by tonsillectomy is to avoid complications like damage of the heart by endocarditis second layer is the myocardium which is the thickest containing the muscles outer layer is the epicardium/visceral layer layers of the heart from inner to outer endocardium myocardium epicardium / visceral pericardial cavity containing pericardial fluid parietal pericardium fibrous pericardium clinical correlation if pericarditis; more secretions of the pericardial fluid leading to pericardial effusion pericardial effusion is the massive increase of the amount of pericardial fluid due to to some diseases like pericarditis cardiac tamponade complication of pericardial effusion where massive pericardial effusion affects the contraction of the heart treatment: cardio synthesis / aspiration of fluid 1.insertion of needle between the left lateral border of xiphoid process and 7th costal cartilage tip of needle must be directed 45 degrees towards direction of left shoulder to aspirate pericardial fluid 2.make a surgical window at the left 4th intercostal space immediately lateral to the sternum the right side of the heart is responsible for collecting the deoxygenated blood the right atrium receives the whole deoxygenated blood of the human body through superior and inferior vena cava the deoxygenated blood passes from the right atrium to the right ventricle through the right atrioventricular orifice which is guarded by tricuspid valve tricuspid valve has 3 cusps: anterior, posterior and septal the deoxygenated blood ejected by the right ventricle through pulmonary valve to the pulmonary artery pulmonary valve / right semilunar valve has 3 cusps (tricuspid): right anterior cusp, left anterior cusp, posterior cusp the only artery carrying deoxygenated blood is the pulmonary artery pulmonary artery divided into right pulmonary artery and left pulmonary artery right pulmonary artery passes to the right lung left pulmonary artery passes to the left lung the deoxygenated blood enters the lung to be filtered by the alveoli each lung sends two pulmonary veins carrying oxygenated blood the only veins carrying oxygenated blood are the 4 pulmonary veins 2 from the right lung and 2 from the left lung pulmonary circulation: small circulation started at the right ventricle and ends at the left atrium wall of left ventricle 3-4 times thicker than right ventricle due to high demand of blood pumping supply blood pressure within left ventricle is 7 times more than within the right ventricle the left side of the heart is responsible for collecting oxygenated blood the left atrium receives the oxygenated blood through the pulmonary veins the oxygenated blood passes from the left atrium to the left ventricle through left atrioventricular orifice guarded by mitral valve mitral valve is a bicuspid valve containing: anterior (larger) and posterior cusps oxygenated blood is pumped by the left ventricle into the aorta through the ventricular aortic orifice guarded by aortic valve / left semilunar valve which is tricuspid containing: anterior, right posterior, left posterior systemic circulation: large circulation needs a large pump formed by the left ventricle wall of left ventricle is 4 times thicker than right ventricle and pressure is 7 times higher than right starts at the left ventricle and ends at the right atrium The heart muscular pumping organ surrounded by pericardium located in the middle mediastinum about 400 grams in weight bilaminar shape shape and size similar to hand fist position is when handfist is placed against the body of sternum and thumb on sternal angle has 4 chambers: right atrium right ventricle left atrium left ventricle has 3 borders: right border left border inferior border has 3 surfaces: anterior surface / sternocostal surface inferior surface / diaphragmatic surface posterior surface / base of the heart has 1 apex directed downward each ventricle ejects 5L of blood in a minute, this volume is called cardiac output 3 borders of the heart the right border formed mainly by the right atrium the left border formed mainly by the left ventricle inferior border formed mainly by the right ventricle 3 surfaces of the heart anterior surface / sternocostal - formed mainly ny right ventricle posterior surface / base - formed mainly by left atrium inferior surface / diaphragmatic - formed mainly by ⅓ right ventricle and ⅔ left ventricle apex of the heart only 1 & directed downward formed completely by the left ventricle surface anatomy: located at left 5th intercostal space 9.5cm lateral to the sternum - mid clavicular line surface anatomy of the borders of the heart: right border formed from the lower border of right third costal cartilage till the lower border of the right sixth costal cartilage 12 mm lateral to the sternum inferior border extends from the lower border of the right sixth costal cartilage to the left fifth intercostal space 9.5 cm lateral to the sternum left border extends from the lower border of left second costal cartilage 2 cm lateral to the sternum extends from the apex superiorly / left fifth intercostal space 9.5 cm lateral to the sternum transverse sinus bounded anteriorly by ascending aorta and pulmonary artery bounded posteriorly by left atrium and superior vena cava clinical use: used to control the bleeding of great vessels during surgical operations - ascending aorta dan pulmonary artery anteriorly and posteriorly superior vena cava and atrium oblique sinus located between 4 pulmonary veins function: allows the expansion of left atrium when filled by blood venous drainage of the heart through 5 cardiac veins: 1. great cardiac vein 2. middle sized cardiac vein 3. small cardiac vein 4. oblique cardiac vein 5. anterior cardiac vein coronary sinus collects blood and drains into the heart from all 5 except anterior cardiac vein cardiac vein opens directly in the right atrium chambers of the heart 1.Right Atrium forms the right border of the heart small chamber but still larger than left atrium receives the whole deoxygenated blood of the human being body through the superior vena cava from the upper part of the body and inferior vena cava from the lower part of the body anterior cardiac vein opens directly and drains into right atrium coronary sinus collecting blood from great cardiac vein, middle sized, small and oblique then opens into the right atrium coronary sinus located between opening of inferior vena cava and interatrial septum sulcus terminalis - located at the outer surface of the right atrium and indicates internally the crista terminalis inner surface of the right atrium: opening of superior vena cava has no valve opening of inferior vena cava has rudimentary valve (no physiological function) opening of coronary sinus between inferior vena cava and interatrial septum containing rudimentary valve crista terminalis located in the same area of sulcus terminalis internally - provides separation between rough area (true right atrium) and smooth area (false right atrium, formed by incorporation of sinus venosus during development from the rough area) false right atrium formed by muscular fibres - pectinate muscles inter atrial septum - the septum separating the right atrium from the left atrium containing foramen called foramen ovale during fetus circulation, it provides passage of blood after birth, it gets obstructed to form fossa ovalis failure of obstruction leads to atrial septal defect ASD the right atrium communicates with right ventricle by right atrioventricular orifice which is guarded by tricuspid valve, containing 3 cusps: anterior, posterior and septal 2.the right ventricle large ventricle but smaller than left ventricle wall of the left ventricle is 4 times thicker than the right ventricle the pressure within the left ventricle is 7 times higher than the right ventricle forming the inferior border of the heart forming the anterior surface of the heart - sternocostal surface sharing information of the diaphragmatic surface / inferior surface by ⅓ communicates with the right atrium by right atrioventricular orifice which is guarded by tricuspid valve externally right ventricle is separated from the left ventricle by interventricular sulcus through which the interventricular artery internal surface of right ventricle: the cavity of right ventricle communicates with right atrium by right atrioventricular orifice which is guarded by tricuspid valve the right ventricle communicates with the pulmonary artery by the right semilunar valve / pulmonary valve consists of 3 cusps: right anterior, left anterior, posterior inner surface characterised by very rough area formed by muscular fibres called trabeculae carneae the trabeculae carneae provides origin for 3 structures: papillary muscles, moderator band, prominent ridge infundibulum - the narrowest area of the right ventricle which leads to pulmonary valve interventricular septum - separates the right ventricle from the left ventricle failure of formation of interventricular septum causes VSD ventricular septal defect papillary muscles of the right ventricle: 3 in number because 3 cusps; anterior, posterior, septal are cylindrical in shape originate from trabeculae carneae sending fibrous structures called corta tend and to be attached to the cusp to prevent the return of the blood to the right atrium during the cistor of right ventricle 3.Left atrium smallest chamber of the heart forming the base / posterior surface of the heart outer surface receives 4 pulmonary veins 2 from the right lung and 2 from the left lung pulmonary veins are the only veins in the body carrying oxygenated blood left side of the heart is the side of oxygenated blood, receives oxygenated blood through left atrium and pumps oxygenated blood through the left ventricle left atrium separate from right atrium by interatrial septum interatrial septum during intrauterine life has foramen ovale after birth, the foramen ovale is obstructed leading to the formation of structure called fossa ovalis failure of the closure of foramen ovale leads to atrial septal defect ASD ASD leads to recurrent infection and affects the lactation leading to loss of weight inner surface has smooth area representing the false atrium and rough area formed by muscular fibres representing the true atrium communication between left atrium and left ventricle is done by left atrioventricular orifice which is guarded by the mitral valve - only bicuspid valve containing 2 cusps: anterior (larger) and posterior structures opening in the left atrium: foramen ovale turning into fossa ovalis 4 pulmonary veins from both lungs left atrioventricular orifice guarded by mitral valve clinical correlation: good relationship between left atrium and oesophagus if any tumour is formed, the oesophagus is compressed leading to dysphagia - inability to swallow 4.The left ventricle larger chamber and most important one chamber of the oxygenated blood because it pumps it to the largest artery of the heart - aorta the wall of left ventricle is 4 times thicker than the right ventricle the blood pressure of the left ventricle is 7 times higher than the right ventricle forming the left border of the heart forming ⅔ of the inferior / diaphragmatic surface of the heart forming the apex of the heart wall between the left ventricle and right ventricle is called interventricular septum failure of the complete formation of interventricular septum leads to the defect of the foramen between right ventricle and left ventricle clinical problem is called ventricular septal defect VSD risk factors: smoking, drugs, genetic factors inner surface of the left ventricle has a rough area formed by muscular fibres called trabeculae carneae which provides origin only for 2 muscles: anterior papillary muscles and posterior papillary muscles which are attached to the cusps of the mitral valve because the mitral valve has 2 cusps: anterior papillary muscles attached to the anterior cups and posterior papillary muscles attached to the posterior cusps tendineae - structures originating from the papillary muscles and attached to the cusps to prevent the return of blood to the left atrium during the contractions of the left ventricle communication between the left ventricle and aorta by: an aortic valve - left semilunar valve (tricuspid valve) 3 cusps: 2 posterior (right posterior and left posterior) and 1 anterior skeleton of the heart / fibrous structure of the heart - strong fibrous tissue structure guarding the orifices of the valves between the atrium and ventricles and fibrous tissues between ventricles and semilunar valves clinical correlation of the 4 chambers: rheumatic heart disease - during childhood, if chronic tonsillitis, which is tonsillitis more than 3 times a month treated by tonsillectomy (surgical removal of tonsils) - chronic tonsillitis usually caused by streptococcal bacteria - streptococcal bacteria sell body structure similar to the shape of the structure of the cells of the valves - child’s body will form antibodies to attack the streptococcal bacteria - the antibodies will not differentiate the shape of the streptococcal bacteria and the cells of the valves and will attack both - bleeding of the valve by fibrosis, affecting the cusp, chordae tendineae and papillary muscles - papillary muscles will not pull the cusps during contraction of the ventricle - blood will return to the atrium - amount of blood ejected by each ventricle will decrease, causing fatigue endocarditis: - inflammation of the endocardium / inner layer from which we have the development of the valves - can be caused by streptococcal bacteria pericardial effusion: - excessive amount of pericardial fluid located in the pericardial cavity - most common cause is pericarditis - inflammation of the cells of the pericardium causing excess secretion of the pericardial fluid cardiac tamponade: - complication of pericardial effusion in which very large amount of pericardial fluid affects the contraction of the heart - treated by cardio synthesis: aspiration of pericardial fluid by insertion of a needle lateral to the xiphoid process between the xiphoid process and left costal cartilage - top of needle must be directed towards the tip of left shoulder by a 45 degree angle - or make a surgical window immediately lateral to the sternum into the left 4th intercostal space right side heart failure: - caused due to the damage of valves, fibrosis and rheumatic heart disease - symptoms: hepatomegaly - enlargement of liver, swelling of lower limbs, increased jugular venous pulse, pulmonary edema surface anatomy of the oscontation of the valves: aortic into the right second intercostal space pulmonary into the left second intercostal space tricuspid behind the midline of the sternum at the lower border mitral at the left fifth intercostal space - same side as the apex of the heart conductive system of the heart: consists of specific cardiac muscle cells function of the conductive system: to organise the contraction and dilation of the atria and ventricles consists of 4 parts: sino atrial node (SA node) - found in wall of right atrium next to the opening of superior vena cava, called the pacemaker atrioventricular node (AV node) - found in wall between right atrium and left atrium - interatrial septum atrioventricular bundle - right carries electrical impulses to the right ventricle and left carries electrical impulses to the left ventricle AV node sends two atrioventricular bundles: right and left SA node sends the signals to the AV node AV node sends them to the left and right atrium AV node sends two atrioventricular bundles: left and right lines of the specific cells of cardiac muscles in a bundle known as bundle of his / atrioventricular bundle blood supply of the conductive system: SA node: 60% of blood supply by right coronary artery 40% of blood supply by left coronary artery AV node: 90% of blood supply by right coronary artery 10% of blood supply by circumference branch of left coronary artery left dominance - if the AV node receives its arterial blood supply from the circumference branch of the left coronary artery because it usually receives from the right coronary artery Innervation of the heart: sympathetic: cervical ganglia and upper thoracic ganglia parasympathetic: vagus nerve clinical correlation innervation of the heart: superficial and deep cardiac plexuses - consisting of sympathetic and parasympathetic - sympathetic from the 3 cervical ganglia (superior,middle,inferior) and upper 4 thoracic sympathetic ganglia - parasympathetic from the vagus nerve and recurrent laryngeal nerve blood supply of the heart: arterial blood supply of the heart: at the root of ascending aortic, anterior/right aortic sinus and posterior/left aortic sinus 1. right coronary artery originating from right/anterior aortic sinus 2. left coronary artery originating from left/posterior aortic sinus right coronary artery: originates from right/anterior aortic sinus which is located on the right side of the root of ascending aorta when it originates from the ventricle provides blood supply to 80% of right atrium and right ventricle except a small percentage by the left coronary artery provides blood supply to the conductive system branches of the right coronary artery: 1. posterior interventricular artery (most imp.) - passing between the 2 ventricles posteriorly / interventricular sulcus posteriorly - provides more than 80% to the right ventricle and less than 20% to the left ventricle - first branch originating from right coronary artery 2. marginal artery (right) - passes through margin of the heart - second branch originating from right coronary artery - also left marginal artery but not imp. 3. SA nodal artery - to the SA node 4. AV nodal artery - to the AV node 5. conus artery left coronary artery: more important than the right one originates from the left/posterior aortic sinus provides blood supply to the left atrium and left ventricle and small area of right side of the heart in 40% of population the SA node receives arterial blood supply from left coronary artery in 10% the AV node receives arterial blood supply from the circumflex branch of the left coronary artery clinical correlation - left dominance, 10% receiving arterial blood supply from the circumflex branch of the left coronary artery left dominance: very short posterior interventricular artery the circumflex artery passing posteriorly and provide blood supply to the AV node occurs in about 10% of population branches of left coronary artery: 1. left anterior descending artery (LADL) / anterior interventricular artery / anterior descending artery / widow artery - first branch coming from left coronary artery - most important 2. circumflex artery 3. left marginal artery 4. diagonal branch clinical correlation of the arterial blood supply: myocardial infarction atherosclerosis - procedure by which we have the formation of atheroma atheroma leads to obstruction of coronary artery risk factors: heavy smoking, hyperlipidemia, hypercholesterolemia, obesity, stress, no exercise uncontrolled hypertension, uncontrolled diabetes, genetic factors once the right coronary artery is obstructed, insufficient blood supply to the cardiac muscle, leads to ischemia ischemia causes ischemic pain ischemic pain causes angina pectoris angina pectoris - severe chest pain due to obstruction of coronary artery which leads to the insufficient blood supply to the cardiac muscle 2 types of angina pectoris: 1. malignant angina pectoris - does not have any cause, happens randomly at any time 2. benign angina pectoris - caused by exercise and subsided with rest angina pectoris without myocardial infarction: angiogram test - coronary artery bypass graft surgery CABG: venous drainage of the heart: 1. great cardiac vein - goes with anterior interventricular 2. the middle cardiac vein - goes with posterior interventricular 3. small cardiac vein - 4. posterior cardiac vein 5. oblique cardiac vein all 5 open into the coronary sinus which opens into the right atrium between the opening of inferior vena cava and interatrial septum 6. anterior cardiac veins - drain directly into the outer surface of the right atrium Lymphatic drainage of the heart: 1. brachiocephalic lymph node 2. tracheobronchial lymph node - located at the carina PSD pulmonary trunk stenosis right ventricular hypertrophy - enlargement in the right ventricle overriding of aorta VSD all 4 cause tetralogy of fallot dextrocardia - heart located into the right side the respiratory system functions: breathing pulmonary ventilation regulation of body temperature gas exchange: ○ delivery of oxygen to the tissues ○ removal of carbon dioxide production of voice protection by: ○ production of mucus ○ sneezing ○ coughing the respiratory tract: consists of: 1. upper respiratory tract 2. lower respiratory tract upper respiratory tract: contents: 1. nose - external nose & and nasal cavity 2. paranasal air sinuses: ○ boney cavities lined by mucus respiratory membrane ○ 4 pairs - frontal sinus, maxillary sinus, sphenoidal sinus, ethmoidal sinus 3. oral cavity 4. pharynx: ○ consists of 3 parts ○ nasopharynx - upper part opening into nose ○ oropharynx - opens into oral cavity ○ laryngopharynx - opens into larynx 5. larynx - last part of upper respiratory tract respiration has 2 types according to the gender: - thoracic in female - abdominal in male the lower respiratory tract: known as bronchial tree contents: 1. trachea: - bifurcates to give left and right main bronchi at the sternal angle - point of bifurcation is carina - lymph node located within the carina / between left and right main bronchi and trachea called tracheobronchial lymph node - tracheobronchial lymph node divided into two - the one located inferior to the carina is inferior tracheobronchial lymph node - the one located superior to the carina is superior tracheobronchial lymph node  2. main bronchi: - right main bronchus: shorter 2.5cm, wider, vertical - left main bronchus: longer 5 cm, narrower, has an acute angle - clinical correlation: if a foreign body swallowed, it ends up in the right main bronchus because it is shorter, wider, and vertical - the foreign body ends up in the lower lobe if the person is standing and if the person is laying down then it ends up in the middle lobe 3. lobar bronchi: - right main bronchus is divided into 3 bronchi, 1 for each lobe - left main bronchus is divided into 2 bronchi, 1 for each lobe 4. segmental bronchi - lobar bronchi divides into smaller segmental bronchi for each segment - bronchopulmonary segments: - lung apex has 3 bronchopulmonary segments: - apical, anterior and posterior bronchopulmonary segments - right lung middle lobe has 2 bronchopulmonary segments: - medial and lateral bronchopulmonary segments - left lung has lingular lobe instead of middle lobe: - superior and inferior lingual bronchopulmonary segments - right and left lower lobes have 5 bronchopulmonary segments: - apical, anterior, lateral, posterior, medial bronchopulmonary segments 5. bronchioles - conducting bronchioles - terminal bronchioles - respiratory bronchioles 6. alveolar ducts 7. alveolar sacs 8. alveoli - each lung consists of 300M in adults and 150M in children the pleura: a thin layer of fibrous tissue containing a layer of mesocilial cells for secretion of pleural fluid consists of 2 layers: 1. parietal layer - located externally 2. visceral layer - located internally, attached to the lung the space between them is called pleural cavity no communication between right pleural cavity and left pleural cavity the parietal layer: located externally lining the inner surface of the thoracic cavity: ribs, vertebrae, diaphragm, suprapleural membrane differ from inner surface by endothoracic facia divided into the following structures:  1. lining the supra pleural membrane - cervical pleura 2. lining the ribs and vertebrae - costovertebral pleura 3. lining the diaphragm - diaphragmatic pleura 4. lining the mediastinal area - mediastinal pleura hilum of the lung - region in which structures pass in and out of the lung pleural cuff - area in the hilum of the lung in which the fusion between parietal and visceral layer is found pleural cuff hanging down to form pulmonary ligaments attachments of the parietal pleura: superiorly - to the inferior border of suprapleural membrane medially - at the middle mediastinum to the pericardium of the heart parietal layer usually extends more inferiorly than the lung, behind both kidneys to provide more space for the expansion of the lung during inspiration costodiaphragmatic recess - junction between the costovertebral pleura and diaphragmatic please is called costomediastinal recess - junction between the costovertebral pleura and costomediastinal recess cervical pleura: divided into a region it lines the surface covered extends up into the neck covers the copula lines the upper surface of the suprapleural membrane extends about 2.5 cm above the middle of clavicle surface anatomy of the parietal pleura: lower border crossing the 8th rib at mid clavicular line lower border crossing the 10th rib at mid axillary more posteriorly crosses the 12th rib at erector spinae muscle blood supply of the parietal pleura: arterial blood supply: 1. internal thoracic artery / internal mammary 2. musculophrenic artery 3. intercostal artery 4. bronchial arteries: - 3 branches - 2 for the left lung and left visceral pleura coming directly from descending thoracic aorta - 1 for the right lung and visceral pleura from right posterior third intercostal artery venous drainage of the parietal pleural : into the azygos system the right parietal pleura into the azygos vein the left parietal pleura into the hemiazygos vein lymphatic drainage of the parietal pleura: 1. intercostal lymph node 2. parasternal lymph node 3. diaphragmatic lymph node 4. posterior mediastinal lymph node cancer in the cell of the parietal pleura - mesothelioma then the enlarger of the 4 lymph nodes innervation of the parietal layer: very sensitive to pain, touch and temperature because it is somatic - costovertebral pleura: by intercostal nerve - cervical pleura: intercostal nerve and receives fibres from C3, C4, C5 - diaphragmatic pleura: phrenic nerve and intercostal nerve - mediastinal pleura - by phrenic nerve only visceral pleura inner layer close to the lung insensitive to pain, touch, and temperature because autonomic innervation consisting of sympathetic and parasympathetic only sensitive to stretching blood supply of the visceral pleura: arterial blood supply of the visceral pleura: bronchial arteries - 3 branches - 2 on the left coming from descending thoracic aorta - 1 on the right coming from posterior third intercostal artery venous drainage of the visceral pleura: azygos system right lung into azygos system left lung into hemiazygos lymphatic drainage of the visceral pleura: similar to parietal layer by bronchopulmonary lymph node superior and inferior tracheobronchial lymph nodes innervation of the visceral layer: autonomic by sympathetic and parasympathetic pulmonary plexuses pleural cavity the space located between the parietal layer externally and the visceral layer internally filled by pleural fluid the pleural fluid secreted by mesothelial cells, 5ml functions: - protection of the ling - separates the lung from neighbouring structures - prevents friction between layers during inspiration clinical correlation of pleura: - pleuritis/pleurisy - inflammation of the pleura - pleural effusion - increased amount of pleural fluid due to several causes: pleuritis, CA lung, CA breast in an x-ray, water is transparent/white colour and air is black management of pleural effusion: - thoracentesis / pleural tap : aspiration of excess pleural fluid by insertion of needle at the 4th costal cartilage at the level of mid axillary line , or at the7th posterior costal cartilage at posterior mid axillary line - mesothelioma - cancer affecting the mesocilial cells - can be damaged during catheterisation of brachiocephalic vein for renal dialysis, the copula can be damaged which is covered by the parietal layer and supra pleural membrane, this can cause a hole, lead to pneumothorax - could be damaged during nephrectomy, because posteriorly the parietal pleura extends more, towards 12th rib, 12th rib level is immediately posterior to kidney, especially on the right because the kidney located more inferiorly about 1-2cm due to the presence of the liver - hemothorax, pneumothorax, hemopneumothorax, hydrothorax, empyema - tension pneumothorax, caused by stab wound, window between intercostal muscle and pleural cavity allows too much air in, which causes shifting of mediastinum to the other side, compression of the other intact lung, atrophy and compression of the injured lung treated by thoracostomy, insertion of chest tube into the 4th intercostal space at the mid axillary line thoracocentesis, insertion of needle to aspirate pleural effusion thoracotomy, surgical window sternotomy, the lungs very important respiratory organs right and left lungs right lung located at the right thoracic cavity and surrounded by the right pleura left lung located at the left thoracic cavity and surrounded by the left pleura each lung is surrounded by pleura vertical space between them is mediastinum pyramidal shape each has 3 surfaces, 3 borders and 1 apex right lung is larger than the left lung because it consists of 3 lobes while the left consists of 2 lobes each lung consists of 300 million alveoli apex of the lung directed upwards surrounded by cervical pleura apex and cervical pleura make up the copula which is covered by suprapleural membrane clinical correlation, when cancer affects the apex it leads to pancoast tumour 3 borders of the lung 1. anterior border - very sharp 2. posterior border - very blunt / rounded 3. inferior border - separates costal surface from diaphragmatic between the anterior border and posterior border we have the medial / mediastinal surface in which the hilum and root of the lung are present 3 surfaces of the lung 1. costovertebral surface / anterior surface 2. mediastinal surface / medial surface - bounded by anterior and posterior borders - at the middle, hilum and root of lung are present - root is the area of attachment of the lung and trachea - hilum contains: pulmonary artery, pulmonary veins, bronchi, bronchial artery and lymphatic vessels, innervation 3. diaphragmatic surface / inferior surface - rests on the diaphragm the right lung larger than the left because it consists of 3 lobes: upper, middle & lower contains 2 fissures: oblique and horizontal - oblique separates the middle lobe from the lower lobe - horizontal separates the upper lobe from the middle lobe the left lung smaller because it consists of 2 lobes: upper and lower lobe contains only 1 fissure: oblique fissure - oblique separates the upper lobe from the lower lobe surface anatomy of the lung: - crosses the 6th rib at mid clavicular line - crosses the 8th rib at mid axillary line - crosses the 10th rib posteriorly at erector spinae muscle surface anatomy of the fissures - oblique fissure: extends from the spinous process of the third thoracic vertebrae posteriorly to cross the 5th and 6th rib anteriorly at the midclavicular line - horizontal fissure: located at the 4th costal cartilage, crosses the oblique fissure at mid axillary line the anatomical relations of the left lungs: ascending aorta arch of aorta left subclavian artery groove for oesophagus diaphragm physiologically the trachea deviates to the right and the oesophagus deviates to the left crossing the midline at sternal angle the anatomical relations of the right lung: diaphragm groove for right subclavian artery groove for trachea azygos vein right vagus nerve inferior vena cava superior vena cava arterial blood supply of the left lung 2 bronchial arteries from the right thoracic aorta arterial blood supply of the right lung 1 bronchial artery from right posterior third intercostal artery venous drainage of left lung hemiazygos vein venous drainage of right lung azygos vein lymphatic drainage of each lung bronchopulmonary lymph node inferior tracheobronchial lymph node superior tracheobronchial lymph node carina: point of bifurcation of the trachea into left and right main bronchi at the level of sternal angle clinical correlation of carina: enlargement of the tracheobronchial lymph node causes bifurcation of the carina and widening of the angle innervation pulmonary plexuses consisting of sympathetic and parasympathetic innervation sympathetic from the thoracic ganglia parasympathetic from the vagus nerve lobar bronchi right main bronchus before entering the lung gives the upper lobar bronchus middle lobar bronchus and lower lobar bronchus originate from right main bronchus within the lung upper, middle and lower brinchi divided into segmental bronchi bronchopulomanry segemtns 10 in each lung right lung upper lobe: apical, anterior, posterior bronchopulomary segments middle lobe: medial, lateral, lower lobe: apical, medial, lateral, anterior, posterior left lung: upper lobe: apical, anterior, posterior lingula: superior, inferior lower lobe: apical, anterior, medial, lateral, posterior clinical correlation lung fibrosis - occurs due to a large number of causes - tuberculosis, when it affects the lung, causes chronic inflammation and pulmonary tuberculosis , leads to lung fibrosis pmeuomnia inflammation of the lung pneumoctomy surgical removal of the lung lobectomy surgical removal of the lobe of the lung pulmonary edema accumulation of fluid within cells of the lung - sign of right side heart failure - accumulation of blood into the right atrium, superior and inferior venacave do not maintain venous return into right atrium, congestion of superior vena cava with blood leads to high jugular venous pulse, congestion of blood into inferior vena cava leads to accumulation of blood into liver which leads to hepatomegaly and lower limbs leads to swelling, and congestion of blood into lungs leads to pulmonary edema, patient shows up with chronic cough - management is done by dioritics to subside the high level of fluid in the lungs CA lung two types, no genetic factors - primary carcinoma - due to heavy smoking - secondary carcinoma, malignant cells from other organs, because the lung receives 100% of the cardiac output