2Internal thoracic artery descends into thorax 1 Internal thoracic artery descends into thorax 1.2cm lateral to edge of sternum, and ends at the sixth costal cartilage by dividing musculophrenic and superior epigastric arteries
4Azygos vein Begins as continuation of right ascending lumbar vein Ascending along the right side of vertebral columnJoins superior vena cava by aching above right lung root at level of T4 to T5Receives right posterior intercostals and subcostal veins plus some of bronchial, esophageal and pericardial veins, and hemiazygos veinTributaries – hemiazygos v. and accessory hemiazygos v., which receive most left posterior intercostals vein and left bronchial veins
5The lymphatic drainage of thorax The lymphatic drainage of thoracic wallTo axillary lymph nodesTo parasternal lymph nodes (along internal thoracic vessels)To intercostals lymph nodes from deeper structures
6lymph nodes of the thoracic contents lymph nodes of trachea, bronchi and lungsPulmonary lymph nodes lie in the angles of bifurcation of branching lobar bronchiBronchopulmonary hilar lymph nodes －lie in the hilus of the lungTracheobronchial lymph nodes －situated above or below the bifurcation of tracheaParatracheal lymph nodes －along each side of the trachea
7Anterior mediastinal lymph node lies anterior to the large blood vessels of thoracic cavity and pericardium; the efferents unite with those of paratracheal lymph nodes, to form the right and left bronchomediastinal trunks. The left bronchomediastinal trunk terminates in thoracic duct, and right in the right lymphtic ductPosterior mediastinal lymph nodes lie along the esophagus and thoracic aorta
8Anterior branches of thoracic nerves Intercostal nerves - (anterior rami of T1- T11): runs forward inferiorly to intercostals vessels in costal groove of corresponding rib, between intercostals externi and intercostals interni; first six nerves are distributed within their intercostals space, lower five intercostals nerves leave anterior ends of their intercostals spaces to enter abdominal wallSubcostal nerve - (anterior ramus of T12): follows inferior border of T12 rib and passes into abdominal wallDistribution: distributed to intercostales and anterolateral abdominal muscles, skin of thoracic and abdominal wall, parietal pleura and peritoneum
9The segmental innervation of anterior surface of trunk T2－sternal angleT4－ nippleT6－xiphoid processT8－costal archT10－umbilicusT12－midpoint between umbilicus and symphysis pubis
11Phrenic nerve Descends over scalenus anterior to enter thorax Accompanied by pericardiophrenic vessels and passes anterior to lung roots between mediastinal pleura and pericardium to supply motor and sensory innervation to diaphragmSensory fibers supply to pleurae, pericardium and peritoneum of diaphragm; usually right phrenic nerve may be distributed on live, gallbladder and biliary system.
12Left vagus nerveEnter thoracic inlet between left common carotid and left subclavian arteries, posterior to left brachiocephalic veinCrosses aortic arch where left recurrent laryngeal nerve branches offPasses posterior to left lung rootForms anterior esophageal plexusForms anterior vagal trunk at esophageal hiatus where it leaves thorax and passes into abdominal cavity , then divides into anterior gastric and hepatic branches
13Right vagus nerve Enter thoracic inlet on right side of trachea Travels downward posterior to right brachiocephalic vein and superior vena cavaPasses posterior to right lung rootForms posterior esophageal plexusForms posterior vagal trunk at esophageal hiatus where it leaves thorax and passes into abdominal cavity, then divides into posterior gastric and celiac branches
14Recurrent laryngeal nerves Right one hooks around right subclavian artery, left one hooks aortic archBoth ascend in tracheo-esophageal grooveNerves enter larynx posterior to cricothyroid joint, the nerve is now called inferior laryngeal nerveInnervations: laryngeal mucosa below fissure of glottis , all laryngeal laryngeal muscles except cricothyroidBronchial and esophageal branches
15Thoracic sympathetic trunk Branches of sympathetic trunk to thoracic plexusesGreater splanchnic nerve - formed by preganglionic fibers from T5~T9 ganglia, and relay in celiac ganglion.Lesser splanchnic nerve - formed by preganglionic fibers from T10~T12 ganglia, and relay in aorticorenal ganglion.The postganglionic fibers supply the liver, spleen, kidney and alimentary tract as far as the left colic flexure.
17Parts and regions of the thorax BoundariesSuperior - jugular notch, sternoclavicular joint, superior border of clavicle, acromion, spinous processes of C7Inferior - xiphoid process, costal arch, 12th and 11th ribs, vertebra T12RegionsThoracic wallThoracic cavity
18Landmarks Jugular notch corresponds with The 2th thoracic vertebra in male, the 3th thoracic vertebra in femaleSternal angle connects 2nd costal cartilage laterally corresponds withThe lower border of 4th thoracic vertebraThe bifurcation of trachea in the adultThe beginning of aortic arch which ends posteriorly at the same levelThe esophagus is crossed by the left main bronchus
19Ribs and intercostal spaces Costal arch Xiphoid process - xiphisternal junction lies opposite the body of the 9th thoracic vertebraClavicleInferior fossa of clavicleCoracoid processRibs and intercostal spacesCostal archInfrasternal angleXiphocostal anglePapillae
20Thoracic wall Skin Superficial fascia Deep fascia Thoracoepigastric v. Supraclavicular n.Anterior and lateral cutaneous branches of intercostal n.Deep fascia
21Lymphatic drainage of breast Into pectoral ln. from lateral and central parts of breastInto apical and supraclavicular ln. from superior part of breastInto parasternal ln. from medial part of breastInto interpectoral ln. from deep part of breastThe lymphatic capillaries of breast form an anastomosing network which is continuous across the midline with that of the opposite side and with that of the abdominal wall
22Internal thoracic vessels Internal thoracic a.&v.Parasternal ln.Endothoracic fascia
24Intercostales externi Origin: lower border of riⅡ)Insertion: upper border of rib below originAction: elevate ribs adding in forced inspirationReplaced anteriorly by external intercostals membrane.Intercostales interniOrigin: upper border of ribInsertion: lower border of rib above originAction: depress ribs for forced expirationReplaced posteriorly by internal intercostals membrane.
25Intercostal space Posterior intercostal v. Posterior intercostal a. Intercostal n.
26DiaphragmShape and position: dome-shaped between thorax and abdomen, consists of a peripheral muscular part and a central tendonOriginSternal part: xiphoid processCostal part: lower six and costal cartilagesLumbar part: arises by two crura from upper 2-3 lumbar vertebraeInsertion: central tendonWeak areas: triangular spaces without muscular tissueLumbocostal triangle: between costal and lumbar parts.Sternocostal triangle: between costal and sternal parts.
27Openings in the diaphragm Aortic hiatus - lies anterior to the body of the 12th thoracic vertebra between the crura. It transmits the aorta, thoracic ductEsophageal hiatus - for esophagus and vagus nerves at level of T10.Vena cava foramen - for inferior vena cava, through central tendon at T8 levelT8T10T12
28Action:Contraction: the dome moving downward, increases the volume of thoracic cavity which results in inspiration, at the same time the intra-abdominal pressure is increased assists in defecation, vomiting or child birth.Relaxation: the dome returns to the former position, reduces the volume to the thoracic cavity, resulting in expiration.
29The MediastinumConcept all of organs between the left and right mediastinal pleurae is called mediastinum. It extends from the sternum in front to the vertebral column behind, and from the thoracic inlet above to the diaphragm below.
30Subdivisions of mediastinum Superior mediastinumInferior mediastinumAnterior mediastinumMiddle mediastinumPosterior mediastinum
31Left side of mediastnum Left subclavian a.Thoracic ductLeft vagus n.Aortic archLeft recurrent n.Thoracic aortaPhrenic n. &pericardiacophrenic a.Sympathetic trunkRoot of lungPericardiumEsophagusGreater splanchnic n
32Right side of mediastnum TracheaLeft vagus n.Superior vena cavaArch of azygos v.Phrenic n. &pericardiacophrenic a.Azygos v.Root of lungSympathetic trunkEsophagusPericardiumInferior vena cava
33Superior mediastinumLocating - from inlet of thorax to plane extending from level of sternal angle anteriorly to lower border of T4 vertebra posteriolyContentsSuperficial layerThymusThree veinsLeft brachiocephelic v.Right brachiocephelic v.Superior vena cava
34Middle layerAotic arch and its three branchesPhrenic n.Vagus n.
36Relations of aortic arch Anteriorly and to the left - pleura, lung phrenic n., pericardiacophrenic vessels and vagus n.Posteriorly and to the right -trachea, esophagus, left recurrent n., thoracic duct, deep cardiac plexusSuperiorly - its three branches, left brachiocephalic v. and thymusInferiorly - pulmonary a., arterial ligament, left recurrent n., left principal bronchus and superficial cardiac plexus
37Triangule of ductus arteriosus Bounded by phrenic n., left vagus n. and left pulmonary a.Contents－ arterial ligament , left recurrent n. and superficial cardiac plexuses
38Inferior mediastinum Anterior mediastinum Location - posterior to body of sternum and attached costal cartilages, anterior to heart and pericardiumContents - fat, remnants of thymus gland, anterior mediastinal lymph nodes
39Middle mediastinumLocation - between anterior mediastinum and posterior mediastinumContents: hart and pericardium, beginning or termination of great vessels, phrenic nerves, pericardiacophrenic vessels , lymph nodes,
40Posterior mediastinum Location - posterior to heart and pericardium, anterior to vertebrae T5 - T12Contents: esophagus, vagus n., thoracic aorta, azygos system of veins, thoracic duct, thoracic sympathetic trunk, posterior mediastinal lymph nodes
41Relations of esophagus Anteriorly - trachea, bifurcation of trachea, left principal branchus, left recurrent n., right pulmonary a., anterior esophageal plexus, pericardium, left atrium, diaphragm
42Posteriorly - posterior esophageal plexus, thoracic aorta, thoracic duct, azygos v., hemiazygos v.,accessory hemiazygos v., right posterior intercostal v.
43Left - left common carotid a. , left subclavian a Left - left common carotid a., left subclavian a., aortic arch, thoracic aorta, superior part of thoracic ductRight - arch of azygos v.
44Relations of thoracic aorta Anteriorly - left root of lung, pericardium and esophagusPosterior - hemiazygos v., accessory hemiazygos v.,Right - azygos v. and thoracic ductLeft - mediastinal pleura
45Thoracic ductBegins in front of L1 as a dilated sac, the cisterna chyli, which formed by joining of left and right lumbar trunks and intestinal trunkEnter thoracic cavity by passing through the aortic hiatus of the diaphragm and ascends along on the front of the vertebral column, between thoracic aorta and azygos veinTravels upward, veering to the left at the level of T5At the roof of the neck, it turns laterally and arches forwards and descends to enter the left venous angle
46Just before termination, it receives the left jugular, subclavian and bronchomediastinal trunks Drains lymph from lower limbs, pelvic cavity, abdominal cavity, left side of thorax, and left side of the head, neck and left upper limbRight lymphatic ductFormed by union of right jugular, subclavian, and bronchomediastinal trunksEnds by entering the right venous angleReceives lymph from right half of head, neck, thorax and right upper limb
47Mediastinal spacesRetrosternal space - lies beween sternum and endothoracic fasciaPretracheal space - lies within superior mediastinum, between trachea, bifurcation of trachea and aortic archRetroesophagus space - lies within superior mediastinum, beween esophagus and endothoracic fascia
48Thoracic aorta Continuation of aortic arch at lower border of T4 Courses downward on left side of, then in front of vertebral columnPasses through aortic hiatus of diaphragm at level of T12 vertebra to enter abdominal cavityMain branchesParietal branchesNine pairs posterior intercostals arteriesOne pair subcostal arteryFor lower nine intercostals spaces and upper part of abdominal wall; superior phrenic arteries supply the superior surface of the diaphragm.Visceral branchesBronchial branches: one or two for each lungEsophageal branchesPericardial branches