1 / 45

THORACIC CAVITY

THORACIC CAVITY. MEDIASTINUM. Mediastinum. Mediastinum = space between lungs. Superior mediastinum: Separated from inferior by horizontal plane between sternal angle and IV disc T4-T5. Fig. 1.34, p 135. Mediastinum. Inferior: Anterior: Middle: Posterior:. Superior Mediastinum.

felice
Download Presentation

THORACIC CAVITY

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. THORACIC CAVITY MEDIASTINUM

  2. Mediastinum • Mediastinum = space between lungs. • Superior mediastinum: Separated from inferior by horizontal plane between sternal angle and IV disc T4-T5. • Fig. 1.34, p 135.

  3. Mediastinum • Inferior: Anterior: Middle: Posterior:

  4. Superior Mediastinum • Retrosternal: Great vessels and branches. Thymus. • Prevertebral: Trachea Esophagus Thoracic duct Sympathetic trunks Vagus nerves

  5. Inferior Mediastinum • Anterior: Thymus, fat, lymph nodes • Middle: Pericardium Phrenic nerves Pericardiacophrenic artery Heart and great vessels

  6. Inferior Mediastinum • Posterior: Esophagus Thoracic duct Aorta and branches Vagus nerves Sympathetic trunks Azygos system of veins

  7. SUPERIOR MEDIASTINUM

  8. Thymus • Occupies superior mediastinum on either side of the midline. • Behind manubrium. • Covered by converging pleura of the lungs. • Involutes with fat after puberty.

  9. Thymus • Blood supply: Anterior mediastinal arteries from internal thoracic artery. Inferior thyroid arteries from subclavian artery. • Venous drainage: Into left brachiocephalic vein.

  10. Thymus • Innervation: Vagus nerve. Cardiac sympathetic plexus.

  11. Middle Mediastinum (inferior) • Pericardium: Encloses heart. (Fig. 1.35, p 137).

  12. Middle Mediastinum (inferior) • Pericardium: Visceral (serous) (Fig 1.37, p 139): = epicardium. Arterial mesocardium. Venous mesocardium. Transverse sinus: Space between arterial and venous mesocardium. Oblique sinus: Space between right and left pulmonary veins.

  13. Middle Mediastinum (inferior) • Pericardium: Pericardial cavity. Parietal (serous): Fused to fibrous pericardium. Fibrous: Fused with central tendon of diaphragm: Pericardiacophrenic ligament. Fused with sternum: Superior and inferior sternopericardial ligaments.

  14. Middle Mediastinum (inferior) • Pericardium: Blood supply (Fig. 1.38, p 139): Pericardial arteries. Pericardiacophrenic arteries. Musculophrenic arteries. Nerve supply: CN X. Phrenic nerve. Sympathetic trunk.

  15. POSTERIOR MEDIASTINUM

  16. Esophagus • From base of neck to: Left of midline to: Midline to: Left of midline. • Passes through diaphragm at level of T10. • Lies: Behind trachea. In front of vertebral column.

  17. Esophagus Blood Supply • Bronchial artery. • Thoracic aorta. • Left gastric artery. • Left inferior phrenic artery.

  18. Esophagus Innervation • Esophageal plexus: Continuation of posterior pulmonary plexus. Formed by right and left vagus nerves: Right vagus nerve  posterior vagus nerve. Left vagus nerve  anterior vagus nerve.

  19. Esophagus Innervation • Upper third: Voluntary muscle. Innervated by recurrent laryngeal nerve. • Lower two-thirds: Involuntary muscle. Innervated by vagus and sympathetic chain.

  20. Left Thoracic duct • Arises from cisterna chyli: At union of right and left lumbar trunks. • Begins on the front of vertebral body T-12 or L-1. • Runs up through the thorax along the front of the vertebral column. • At first it lies to the right of midline.

  21. Left Thoracic duct • It moves over to the left side when it reaches level T-5. • Receives most of lymph from body below diaphragm. • Drains left side of thoracic cavity and part of right.

  22. Left Thoracic duct • Receives lymph from left internal jugular lymph trunk. • Receives lymph from left subclavian lymph trunk. • Empties into venous system at junction of: Left internal jugular vein. Left subclavian vein.

  23. Right Thoracic duct • Drains upper right thoracic cavity, right upper extremity, and right side of head and neck. • Empties into venous system at junction of: Right internal jugular vein. Right subclavian vein.

  24. Thoracic Sympathetic Chain • Lies against neck of ribs and costovertebral junctions. • 12 thoracic ganglia pairs: First one often fused with inferior cervical ganglion: Referred to as stellate ganglion collectively.

  25. Thoracic Sympathetic Chain • Cervical ganglia: Superior. Middle. Inferior.

  26. Thoracic Sympathetic Chain • The preganglionic sympathetic supply to the thoracic viscera are from T1–5. • The postganglionics are from: Superior, middle, and inferior cervical ganglia. T1-T5 paravertebral ganglia. • They exit the chain as direct fibers and travel downwards to enter the thorax: As cardiopulmonary splanchnic nerves.

  27. Thoracic Sympathetic Chain • The cardiopulmonary splanchnic nerves travel on their own and do not accompany other nerves or vessels. • Function: Coronary artery dilation. Increase heart rate. Bronchodilation.

  28. Splanchnic Nerves • Composed of preganglionic fibers and visceral sensory fibers. • Supply abdominal viscera. • Synapse in prevertebral ganglia. • Refer in text to Figure 1.41, page 63.

  29. Splanchnic Nerves • Greater: T5-T9. Synapses in celiac ganglion. • Lesser: T10-T11. Synapses in the superior mesenteric ganglion.

  30. Splanchnic Nerves • Least: T12. Synapses in the aorticorenal ganglion.

  31. Vagus Nerve • Cranial nerve X • Major parasympathetic supply to thoracic and abdominal viscera.

  32. Course of Vagus Nerve • Parallel to esophagus: Innervates esophagus • Passes posterior to root of lung on each side. • Pierces diaphragm with esophagus. • Becomes gastric nerve. • Supplies viscera in thoracic cavity.

  33. Vagus Nerve Branches • Cardiac branches to cardiac plexus. • Pulmonary branches to pulmonary plexus. • Esophageal branches to esophageal plexus.

  34. Vagus Nerve Branches • Left recurrent laryngeal nerve from left vagus: Hooks around arc of aorta to left of ligamentum arteriosum. • Right recurrent laryngeal nerve from right vagus: Hooks around subclavian artery. Therefore: arises in neck, not thorax.

  35. Phrenic Nerve • Arises in neck from: Ventral rami of C3-5 (C4 = major contribution) • Passes anterior to pulmonary root on each side (only nerve to do so). • Sole motor innervation to diaphragm. • Sensory fibers to pericardium, mediastinal pleura, and pleural and peritoneal coverings of diaphragm.

  36. Phrenic Nerve • Pain via phrenic nerves usually referred to base of neck and tip of shoulder. • Accompanied by pericardiacophrenic arteries. Branches of internal thoracic arteries

  37. Lymphatic Drainage • 50 tracheobronchial lymph nodes : Some of the largest lymph nodes in the body. Include: Paratracheal Superior tracheobronchial Inferior tracheobroncial Bronchopulmonary Pulmonary Text: p 131, Fig. 1.32

  38. Lymph Drainage of Thoracic Cavity • Parasternal nodes: Lie behind sternum along course of internal thoracic artery. Receive lymph from thoracic wall, upper anterior abdominal wall, and diaphragm. Also receive significant amount of lymph from mammary gland. Dump into parasternal lymph channel.

  39. Lymph Drainage of Thoracic Cavity • Posterior intercostal nodes: Lie in posterior intercostal space between heads of ribs. Receive lymph from thoracic wall and paravertebral regions. Drain into thoracic duct: From left and lower right. Drain into right lymphatic duct: From upper right.

  40. Lymph Drainage of Thoracic Cavity • Diaphragmatic nodes: Lie on upper surface of diaphragm. Receive lymph from diaphragm, pericardium, upper surface of liver. Drain to parasternal and posterior mediastinal nodes.

  41. Lymph Drainage of Thoracic Cavity • Posterior mediastinal nodes: Lie along esophagus and descending thoracic aorta. • Brachiocephalic nodes: Lie along brachiocephalic veins.

  42. Lymphatic Drainage of Thorax • Lymph Trunks Bronchiomediastinal lymph trunks receive lymph from: Posterior mediastinal nodes Brachiocephalic nodes Tracheobronchial nodes Parasternal nodes

  43. Lymphatic Drainage of Thorax • Thoracic Duct Begins in abdomen on right side of midline. Receives most of lymph from body below diaphragm. Drains left side of thoracic cavity and part of right. Receives lymph from left internal jugular lymph trunk.

  44. Lymphatic Drainage of Thorax • Thoracic Duct (cont.): Receives lymph from left subclavian lymph trunk. Empties into venous system at junction of: Left internal jugular vein. Left subclavian vein.

  45. Lymphatic Drainage of Thorax • Right Lymphatic Duct: Drains upper right thoracic cavity, right upper extremity, and right side of head and neck. Empties into venous system at junction of: Right internal jugular vein. Right subclavian vein.

More Related