Thoracic Cage and Diaphragm TBL Material PDF

I Thoracic Cage and Diaphragm. Intercostal spaces Intercostal spaces lie between adjacent ribs and are filled by intercostal muscles. Fit I...

I Thoracic Cage and Diaphragm. Intercostal spaces Intercostal spaces lie between adjacent ribs and are filled by intercostal muscles. Fit I so I II a n S Intercostal Space. ( A ) Anterolateral view. ( B ) Details of an intercostal space and relationships.( C ) Transverse section. Intercostal nerves and associated major arteries and veins lie in the costal groove along the E inferior margin of the superior rib and pass in the plane between the inner two layers of muscles. F In each space, the vein is the most superior structure and is therefore highest in the costal groove. α The artery is inferior to the vein, and the nerve is inferior to the artery and often not protected by f eve.TTmost the superior Foley often not protected structure is the highest in by thegroove costalgroove Inferiorto the vein  is the Artery Nerve is inferiorto the Arteryand offer is not protected by the Mof groove the groove. Therefore, the nerve is the structure most at risk when objects perforate the upper aspect of an intercostal space. Small collateral branches of the major intercostal nerves and vessels are often present superior to the inferior rib below. Deep to the intercostal spaces and ribs, and separating these structures from the underlying pleura, is a layer of loose connective tissue, called endothoracic fascia, which contains variable amounts of fat. Superficial to the spaces are deep fascia, superficial fascia, and skin. Muscles associated with the EFf upper limbs and back overlie the spaces. Muscles Muscles of the thoracic wall include those that fill and support the intercostal spaces, those that pass between the sternum and the ribs, and those that cross several ribs between costal attachments Tia ( Table). Muscle Muscles of the thoracic wall Innervation Function Entire External Intercostal nerves;Most active during inspiration; supports intercostal intercostal Internal I T1–T11 so space; moves ribs superiorly Intercostal nerves;Most active during expiration; supports intercostal intercostal T1–T11 space; moves ribs inferiorly Innermost Intercostal nerves;Acts with internal intercostal muscles intercostal T1–T11 Emattta I Subcostales maydepressribs Related intercostalMay depress ribs nerves Transversus Depresse costal cartilage Related intercostalDepresses costal cartilages thoracis nerves The muscles of the thoracic wall, together with muscles between the vertebrae and ribs posteriorly (i.e., the levatores costarum and serratus posterior superior and serratus posterior inferior muscles) alter the position of the ribs and sternum and so change the thoracic volume iiiii.TT during breathing. They also reinforce the thoracic wall. musieitinevtnetiti.ae IzFIf Eternal ribi posteriorly apa treat.ua sevatores costamm most meansInner costa nerve III a serratus posterior superior posterior Inferior 4Serratus  Intercostal muscles retina ÉÉ Ee The intercostal muscles are three flat muscles found in each intercostal space that pass between adjacent ribs. Individual muscles in this group are named according to their positions: eEmi ii ▪ The external intercostal muscles are the most superficial. FEIEFEE.EE ▪ The internal intercostal muscles are sandwiched between the external and innermost muscles. ▪ The innermost intercostal muscles are the deepest of the three muscles. The intercostal muscles are innervated by the related intercostal nerves. As a group, the intercostal muscles provide structural support for the intercostal spaces during breathing. They can also move ITP the ribs. me External intercostal muscles FIFTIES The eleven pairs of external intercostal muscles extend from the inferior margins (lateral edges of costal grooves) of the ribs above to the superior margins of the ribs below. When the thoracic wall is viewed from a lateral position, the muscle fibers pass obliquely anteroinferiorly. The muscles extend around the thoracic wall from the regions of the tubercles of the ribs to the 1  thin connectivetissueaponeurosis externalmmingergtal egg costal cartilages, where each layer continues as a thin connective tissue aponeurosis termed sprony.IE the external intercostal membrane. The external intercostal muscles are most active in ITFA inspiration. Internal intercostal muscles Paraffin extend from Jefe The eleven pairs of internal intercostal muscles pass between the most inferior lateral edge of e the costal grooves of the ribs above, to the superior margins of the ribs below. They extend from e parasternal regions, where the muscles course between adjacent costal cartilages, to the angle of the ribs posteriorly. This layer continues medially toward the vertebral column, in each intercostal space, as the internal intercostal membrane. The muscle fibers pass in the opposite direction to those of the external intercostal muscles. When the thoracic wall is viewed from a lateral position, the muscle fibers pass obliquely posteroinferiorly. The internal intercostal muscles are Do infantryintercostalmuscle most active during expiration. ribs more the Innermost intercostal muscles least distinct of the The innermost intercostal muscles are the least distinct of the intercostal muscles, and the e fibers have the same orientation as the internal intercostals. These muscles are most evident in the lateral thoracic wall. They extend between the inner surfaces of adjacent ribs from the medial edge of the costal groove to the deep surface of the rib below. Importantly, the neurovascular bundles use associated with the intercostal spaces pass around the thoracic wall in the costal grooves in a plane between the innermost and internal intercostal muscles. the n Acts with Intel  lower region Deepsurface of ofposterior thoracic Anterior thoracic wall wall Subcostales and Transversus thoracis muscles both are at same of minemost plane Intercostal muscle subcostal mush spiked lower region of the posterior thoracic a same plane as Innermost Posterior thoracic Intercostal mute Wall Anterior Transvens tho tinamous DagFustace of the thorman Anterior thoracic wall same plane as Imminently Deep to Internal thoracic vessel The subcostales are in the same plane as the innermost intercostals, span multiple ribs, and are more numerous in lower regions of the posterior thoracic wall. The transversus thoracis muscles are found on the deep surface of the anterior thoracic wall and in the same plane as the innermost intercostals. The transversus thoracis muscles lie deep to the internal thoracic vessels and secure these vessels to the wall. as same planeIntervost subcostal Innermost Transversus thoracic muscle eeptsuniiitoitmaieseee.ee so I't 025 Anterior thoracic wall lower region of the same plane of Innermost Intercostal posterior thoracic wall  Find Jtifftal It Arterial supply A soso.rs originate from the Internal JO main Aorta thoracicartery I P e Esae petition toss Vessels that supply the thoracic wall consist mainly of posterior and anterior intercostal arteries, which pass around the wall between adjacent ribs in intercostal spaces. These arteries originate from the aorta and internal thoracic arteries, which in turn arise from the subclavian arteries in the F.I.ee root of the neck. Together, the intercostal arteries form a basket-like pattern of vascular supply e around the thoracic wall. FE. P Posterior intercostal arteries Posterior intercostal arteries originate from vessels associated with the posterior thoracic wall. The upper two posterior intercostal arteries on each side are derived from the supreme Feces intercostal artery, which descends into the thorax as a branch of the costocervical trunk in the neck. The costocervical trunk is a posterior branch of the subclavian artery. stalottenes upper two posterior Intercostal arteries posterion on each side derived FOG descends into  Potus scent longer vessel in the right is longer than the left The remaining nine pairs of posterior intercostal arteries arise from the posterior surface of the III thoracic aorta. Because the aorta is on the left side of the vertebral column, those posterior intercostal vessels passing to the right side of the thoracic wall cross the midline anterior to the bodies of the vertebrae and therefore are longer than the corresponding vessels on the left. In addition to having numerous branches that supply various components of the wall, the posterior intercostal arteries have branches that accompany lateral cutaneous branches of the intercostal Ttt nerves to superficial regions. F 2 Anterior intercostal arteries f.fi The anterior intercostal arteries originate directly or indirectly as lateral branches from the E internal thoracic arteries. Each internal thoracic artery arises as a major branch of the subclavian artery in the neck. It passes anteriorly over the cervical dome of the pleura and descends vertically through the superior thoracic aperture and along the deep aspect of the anterior thoracic wall. On each side, the internal thoracic artery lies posterior to the costal cartilages of the upper six ribs and about 1 cm lateral to the sternum. At approximately the level of the sixth intercostal space, it divides into two terminal branches: the superior epigastric artery , which continues inferiorly into the anterior abdominal wall and the musculophrenic artery , which passes along the costal margin, goes through the diaphragm, and ends near the last intercostal space. Anterior intercostal arteries that supply the upper six intercostal spaces arise as lateral branches E from the internal thoracic artery, whereas those supplying the lower spaces arise from the musculophrenic artery. In each intercostal space, the anterior intercostal arteries usually have two branches: One passes below the margin of the upper rib. The other passes above the margin of the lower rib and meets a collateral branch of the posterior intercostal artery. J The distributions of the anterior and posterior intercostal vessels overlap and can develop anastomotic connections. The anterior intercostal arteries are generally smaller than the posterior vessels. Anterior Intercostal arteries From Internal Originate terminal branches gives 2 thoracic artery Tusclophrenic artery superior epigastric artery goes throng the Diaphragm Continous Inferiorly the last and endé near into the anterior Intercostal space abdominal wall  Venous drainage BIG Yt_ which will connect to the brackrocephalk veins in theneck confytheintrustaverns will drain's into the of vein azygos system Internal thoracic vein Venous drainage from the thoracic wall generally parallels the pattern of arterial supply. Centrally, the intercostal veins ultimately drain into the azygos system of veins or into internal thoracic veins , which connect with the brachiocephalic veins in the neck. Often the upper posterior intercostal veins on the left side come together and form the left superior intercostal vein , which empties into the left brachiocephalic vein. Similarly, the upper posterior intercostal veins on the right side may come together and form the right superior intercostal vein , which empties into the azygos vein. venfsten.orostal upper rInter ft Ignt ItLe form fightsupers Form left Superior intercostal vein Intercostal vein JEFFERp emptyttothe 424905 empty to leffv.am vein  n left subclaw here Intercostal nerves Innervation mainly by intercostal A is the FE t.FI laterablted mood WAS decides into two A EIJjg.tn Fee T Tn Innervation of the thoracic wall is mainly by the intercostal nerves , which are the anterior rami 5 of spinal nerves T1 to T11 and lie in the intercostal spaces between adjacent ribs. The anterior Is ramus of spinal nerve T12 (the subcostal nerve ) is inferior to rib XII.A typical intercostal nerve passes laterally around the thoracic wall in an intercostal space. The largest of the branches is the lateral cutaneous branch, which pierces the lateral thoracic wall and divides into an A anterior branch and a posterior branch that innervate the overlying skin. The intercostal nerves end as anterior cutaneous branches , which emerge either parasternally, between adjacent costal cartilages, or laterally to the midline, on the anterior abdominal wall, to supply the skin. In addition to these major branches, small collateral branches can be found in the intercostal space running along the superior border of the lower rib. E In the thorax, the intercostal nerves carry: somatic motor innervation to the muscles of the thoracic wall (intercostal, subcostal, and transversus thoracis muscles), somatic sensory innervation from the skin and parietal pleura, and postganglionic sympathetic fibers to the periphery.Sensory innervation of the skin overlying the upper thoracic wall is supplied by cutaneous branches (supraclavicular nerves), which descend from the cervical plexus in the neck. In addition to innervating the thoracic wall, intercostal nerves innervate other regions: The anterior ramus of T1 contributes to the brachial plexus. The lateral cutaneous branch of the second intercostal nerve (the intercostobrachial nerve) contributes to cutaneous innervation of the  medial surface of the upper arm. The lower intercostal nerves supply the muscles, skin, and peritoneum of the abdominal wall. trapperantiquity IN THE CLINIC: THORACOSTOMY (CHEST) TUBE INSERTION Insertion of a chest tube is a commonly performed procedure and is indicated to relieve air or fluid trapped in the thorax between the lung and the chest wall (pleural cavity). This procedure is done for pneumothorax, hemothorax, hemopneumothorax, malignant pleural effusion empyema, É hydrothorax, and chylothorax, and also after thoracic surgery. ÉÉ ʰ The position of the thoracostomy tube is usually between the anterior axillary and midaxillary anatomical lines from anterior to posterior and in either the fourth or fifth intercostal space. The 4174754 position of the ribs in this region should be clearly marked. Anesthetic should be applied to the superior border of the rib and the inferior aspect of the intercostal space, including one rib and space above and one rib and space below. The neurovascular bundle runs in the neurovascular plane, which lies in the superior aspect of the intercostal space (just below the rib), hence the reason for positioning the tube on the superior border of a rib (i.e., at the lowest position in the intercostal space). Chest tube insertion is now commonly done with direct ultrasound guidance. This approach meant a allows the physician both to assess whether the pleural effusion is simple or complex and loculated, and to select the safest site for entering the pleural space. In some cases of pneumothorax, a chest drain can be inserted under CT-guidance, especially in patients with ii underlying lung disease where it is difficult to differentiate a large bulla from free air in the pleural space. IN THE CLINIC: INTERCOSTAL NERVE BLOCK Local anesthesia of intercostal nerves produces excellent analgesia in patients with chest trauma and in those patients requiring anesthesia for a thoracotomy, mastectomy, or upper abdominal Trestle surgical procedures. tuato The intercostal nerves are situated inferior to the rib borders in the neurovascular bundle. Each ITI neurovascular bundle is situated deep to the external and internal intercostal muscle groups. mm borders The nerve block may be undertaken using a “blind” technique or under direct imaging guidance. in the The patient is placed in the appropriate position to access the rib. Typically, under ultrasound guidance, a needle may be advanced into the region of the subcostal groove, followed by an neugonvae.la injection with a local anesthetic. Depending on the type of anesthetic used, analgesia may be short- or long-acting. bbundle each Given the position of the neurovascular bundle and the subcostal groove, complications may saturated include puncture of the parietal pleura and an ensuing pneumothorax. Bleeding may also occur if the artery or vein is damaged during the procedure. Yeti e Internal Intercostal muscle patient pieur ensuing premothorax if there bleeding can occur vein artery damage to  age thoracic cavity separate the from the abdominal cavity Diaphragm musculotendinous structure fills the inferior that aperture thereof I It typhoid progestin xiphoid process of stenMM the stemun costal margin The diaphragm is a thin musculotendinous structure that fills the inferior thoracic aperture and separates the thoracic cavity from the abdominal cavity. It is attached peripherally to the: xiphoid process of the sternum, costal margin of the thoracic wall, ends of ribs XI and XII, ligaments that span across structures of the posterior abdominal wall, and vertebrae of the lumbar region. From these peripheral attachments, muscle fibers converge to join the central tendon. The pericardium is attached to the middle part of the central tendon. E a Structures traveling between the thorax and abdomen pass through the diaphragm or between the diaphragm and its peripheral attachments: so The inferior vena cava passes through the central tendon at approximately vertebral level TVIII. Till 8 IVC 78 the muscular part of the esphophagus To pass through medline to the left diaphragm just at love TO  Aorta at lone 712 passes the posterior attachment The esophagus passes through the muscular part of the diaphragm, just to the left of midline, approximately at vertebral level TX. The vagus nerves pass through the diaphragm with the esophagus. E The aorta passes behind the posterior attachment of the diaphragm at vertebral level TXII. The thoracic duct passes behind the diaphragm with the aorta. The azygos and hemiazygos veins may also pass through the aortic hiatus or through the crura of the diaphragm. Innervation Crura The diaphragm is innervated by the phrenic nerves (C3, C4, and C5), which penetrate the diaphragm and innervate it from its abdominal surface. Contraction of the domes of the diaphragm flattens the diaphragm, thereby increasing thoracic volume. Movements of the diaphragm are essential for normal breathing. IN THE CLINIC: DIAPHRAGMATIC PARALYSIS In cases of phrenic nerve palsy, diaphragmatic paralysis ensues, which is manifested by the elevation of the diaphragm muscle on the affected side. The most important cause of the phrenic nerve palsy that should never be overlooked is malignant infiltration of the nerve by lung cancer. 2 Other causes include postviral neuropathy (in particular, related to varicella zoster virus), trauma, iatrogenic injury during thoracic surgery, and degenerative changes in the cervical spine with o compression of the C3–C5 nerve roots. nerve Cs Ca 5 Diaphragm is innervated phrenic by Innervate it which penetrate the diaphram abdominal surface from its