Diaphragm_and_Posterior_Abdominal_Wall_2023.pptx

Diaphragm and Trunk Wall, PART 2: Diaphragm and Trunk Wall, PART 2: Thoraco-abdominalDIAPHRAGM DIAPHRAGM Thoraco-abdominal && POSTERIORTRUNK TRUNKWALL WALL POSTERIOR Learning Objectives 5. Name locate, and describe the thoracoabdominal diaphragm, its component parts, and how it functions in breat...

Diaphragm and Trunk Wall, PART 2: Diaphragm and Trunk Wall, PART 2: Thoraco-abdominalDIAPHRAGM DIAPHRAGM Thoraco-abdominal && POSTERIORTRUNK TRUNKWALL WALL POSTERIOR Learning Objectives 5. Name locate, and describe the thoracoabdominal diaphragm, its component parts, and how it functions in breathing. Thoracoabdominal diaphragm - A partition dividing the body cavity into thoracic and abdomino-pelvic portions - Protects lungs and heart from pressure that would otherwise be caused by the massive amount of heavy, often mobile, abdominal viscera - Participates in respiration; primary muscle utilized in breathing Note: on the right, the dome of the diaphragm is higher than on the left, due to the presence of the underlying liver. However, the liver, and other underlying viscera move with diaphragmatic contractions. Moore, et al., 7th ed. erings of the superior aspect of the diaphragm Anterior - Parietal pleura of the left and right pleural sacs - Fibrous pericardium - Endothoracic fascia Note: the fibrous pericardium is fused directly to the dome of the diaphragm; thus, the pericardial sac (and its contents) are moved and distorted with diaphragmatic contractions Note also: the main tendon of the diaphragm is located centrally, at the top of its dome, with the diaphragmatic musculature surrounding it on the periphery. Diaphragm, superior view Thoracoabdominal Diaphragm Attachments Anterior, in the midline: xiphoid process Anterolateral: costal margin Posteriorly: L1 and L2 vertebral bodies and Intervertebral disc ote: the portions of the diaphragm ttaching to the vertebral column are the rura or ‘legs’ of the diaphragm. From: Moore and Agur, 2007. Palpating the Diaphragm Note: both thumbs are reaching underneath the costal margin, along the diaphragmatic attachment. Beil, p. 214 Shape of the diaphragm in the Midsagittal plane anterior  The diaphragm is attached more inferiorly posteriorly vs. anteriorly. From: Moore and Agur, 2007. Vertical increase in thoracic Dimensions/capacity -diaphragmatic contraction flattens the dome of the diaphragm Learning Objective 5: Application Name locate, and describe the thoracoabdominal diaphragm, its component parts, and how it functions in breathing. Ask yourself: • What are the benefits of having the fibrous pericardial sac fused to the diaphragm? • Which ribs is the diaphragm attached to? • Where are the contractile diaphragmatic fibers? Tendinous? What are some of the functional implications of this arrangement? Learning Objectives 6. Name, locate, and describe the musculoskeletal structures comprising the posterior abdominal wall, including their attachments, innervation, blood supply, and function. Thoraco-abdominal diaphragm quadratus lumborum psoas major Iliacus Muscles of the Posterior Abdominal Wall central tendon opening for IVC lateral arcuate ligament medial arcuate ligament Note: the IVC traverses the diaphragm at its central tendon. esophageal hiatus aortic hiatus left crus right crus Thoraco-Abdominal Diaphragm Muscles of the Posterior Abdominal Wall Psoas Major Origin: transverse processes, bodies, and intervertebral discs of T12-L5 Insertion: lesser trochanter of femur Innervation: L1,2,3 ventral rami Function: flexes thigh at hip; with lower limb fixed, flexes vertebral column laterally(unilateral) or flexes trunk on hip (bilateral) Iliacus Origin: superior 2/3 of iliac fossa; ala of sacrum, and anterior sacroiliac ligament Insertion: lesser trochanter Innervation: femoral N. Function: flex thigh on hip; stabilizes and gives integrity to hip joint Quadratus Lumborum Origin: medial ½ of inferior border of rib 12 and tips of lumbar transverse processes Insertion: iliolumbar ligament and internal lip of iliac crest Innervation: ventral rami of T12 – L4 spinal nerves Function: extends and laterally flexes trunk; fixes rib 12 during inhalation Back Muscles, Superficial Group thoracolumbar fascia Note the lumbar triangle midsagittal plane What segmental vessels supply arterial blood to these muscles of the posterior abdominal wall? Venous drainage? A: Lumbar arteries and veins Note the lumbar triangle Relationship of back & abdominal wall musculature to thoracolumbar fascia Learning Objective 6: Application Name, locate, and describe the musculoskeletal structures comprising the posterior abdominal wall, including their attachments, innervation, blood supply, and function. Ask yourself: • Which muscle of the posterior abdominal wall can depress the 12 th rib? • What is the relationship between the fascia of this muscle and that of the psoas major? Latissimus dorsi? Sheet muscles of the anterolateral abdominal wall? Thoracolumbar fascia? Learning Objectives 7. Name and locate the diaphragmatic apertures (including their vertebral levels) and what they transmit; describe congenital and hiatal diaphragmatic hernias, and their clinical significance. Diaphragmatic apertures: anterior T8 Inferior vena cava T10 esophagus vagal trunks T12 aorta azygous vein thoracic duct Clemente, C. THORACO-ABDOMINAL DIAPHRAGM: SUPERIOR ASPECT Congenital Diaphragmatic hernia -showing 1. Intrusion of bowel into thoracic cavity 2. Displacement of heart towards right 3. Lack of left lung inflation https://radiopaedia.org/cases/congenital-diaphragmatic-hernia-6 Hiatal hernia -potential complications 1. 2. 3. 4. Esophageal stricture Strangulated hernia Barrett’s esophagus Ulcerations or stomach bleeding https://www.drmatthewlublin.com/contents/hiatal-hernia-surgery/hiatal-hernia-surgery-overview Learning Objective 7: Application Name and locate the diaphragmatic apertures (including their vertebral levels) and what they transmit; describe congenital and hiatal diaphragmatic hernias, and their clinical significance. Ask yourself: • Why are the more posterior apertures of the diaphragm at lower vertebral levels? • How does the muscle surrounding the esophageal hiatus act as a sphincter to prevent reflux of stomach contents into the distal esophagus? • Why doesn’t the IVC get constricted by the diaphragm as it passes through it? Learning Objectives 8. Describe the innervation of the of the diaphragm; explain the functional consequences of hemidiaphragmatic paralysis and the pattern of referred pain from the diaphragm and phrenic nerve. Hemidiaphragmatic Paralysis - Injury to a phrenic nerve, resulting in unilateral paralysis Consequences: Lack of coordination between left and right sides of muscle, compromising ability to increase thoracic capacity for lung inflation Diaphragmatic Innervation 1. Phrenic Nerve (C 3, 4, 5) -contains motor fibers to the diaphragm -afferent fibers from diaphragm, fibrous and parietal pericardium, diaphragmatic pleura, mediastinal pleura 2. Lower 6 or 7 intercostal and the subcostal NN. -afferent fibers from peripheral diaphragm hrenic nerves in relation o pleural and pericardial acs Right phrenic N. Left phrenic N. Note that the phrenic N. carries 1. axons supplying motor innervation to the diaphragm as well as 2. somatic sensory axons that convey pain and touch information from diaphragm diaphragmatic pleura mediastinal pleura fibrous pericardium parietal pericardium Look at the course of the phrenic N. in this llustration, and the areas from which it caries sensory information should make sense! Question: what nerves are located in the intercostal spaces and Referred Pain from Phrenic N. from Mediastinal and Central Diaphragmatic Pleura with the result that the patient feels discomfort in the neck and/or shoulder. NOTE: this is because the Phrenic N. is made up of ventral rami of spinal nerves from C3, 4, and 5 levels. In the dermatome diagram below, you can clearly see why this pain would be referred to the neck and/or shoulder. Plate 162 Netter, F.H. Atlas of Human Anatomy, 6th Edition. Elsevier, 2014. rritation or injury to the peripheral portions of the diaphragm are felt in the body wall, as these regions of t gm are innervated by branches of intercostal nerves. Learning Objective 8: Application Describe the innervation of the of the diaphragm; explain the functional consequences of hemidiaphragmatic paralysis and the pattern of referred pain from the diaphragm and phrenic nerve. Ask yourself: • To what dermatomes is diaphragmatic pain referred? • Where else might such referred pain originate? • What is the course of the phrenic nerve? Learning Objectives 9. Describe the vascular supply and lymphatic drainage of the diaphragm and posterior abdominal wall; relate these to the vascular and lymphatic drainage of the anterior abdominal wall. Abdominal Aorta, direct branches gins at the aortic hiatus of the diaphragm: T12 Unpaired branches - Celiac trunk - Superior mesenteric - Inferior mesenteric - Median sacral Paired branches - Inferior phrenic - Middle suprarenal - Renal - Gonadal (testicular or ovarian) - 1st – 4th lumbar - Common iliac Ends at: L4 Supplying Posterior Abdominal W Lumbar arteries Inferior phrenic arteries IVC, direct tributaries IVC and Azygous system veins of posterior abdominal wall Unpaired tributaries (distal to proximal) Right gonadal (testicular or ovarian) Right suprarenal Hepatic veins Paired tributaries (distal to proximal) Common iliac Renal 3rd and 4th Lumbar Inferior phrenic Azygous system Receives ascending lumbar veins = junctions with the Azygous system Blood supply to the diaphragm • • • • • Intercostals Musculophrenics Pericardiophrenics Superior phrenics Inferior phrenics ymphatic Drainage of the Diaphragm wed from above) anterior https://link.springer.com/chapter/10.1007/978-0-387-09515-8_5 phatic Drainage of the Posterior Abdominal Wall Moore, et al., 7th ed. ains of nodes along the aorta and its main branches converge at the cisterna chyli, together with the intest d lumbar trunks, to form the thoracic duct. Learning Objective 9: Application Describe the vascular supply and lymphatic drainage of the diaphragm and posterior abdominal wall; relate these to the vascular and lymphatic drainage of the anterior abdominal wall. Ask yourself: • What provides arterial blood to the diaphragm? • To which lymph nodes do various parts of the diaphragm drain? Learning Objectives 10. Name and describe the structures moving the thoracic wall and explain how they assist the diaphragm with inhalation and exhalation. Costo-vertebral Joints s articulate with vertebrae at two places: Head, articulates with vertebral body Tubercle, articulates with transverse process A-P increase in thoracic Dimensions Rotation and elevation of ribs at the costo-vertebral joints pushes the sternal body anteriorly by flexing it on the manubrium at the sternal angle. Side to side increase in thoracic Dimensions Elevation of the ribs brings them into a more horizontal position and thus increases side-to-side thoracic diameter. Which muscles alter thoracic diameter? Hint: not the intercostal muscles! Accessory Muscles of Respiration Potentially any muscles attaching to the thoracic cage. Runners ‘fixing’ their upper limbs, thus enabling accessory muscles of respiration that attach to the upper extremity to instead elevate the ribs to maximize an increase in thoracic volum inspiration. http://missionimpossibleulysses.files.wordpress.com/2011/05/race.jpg Upward pull of sternocleidomastoid on the clavicle elevates the ribs a) as the clavicle is functionally integrated into the thoracic cage via the subclavius muscle b) If the first rib is elevated, the others will follow due to their connections via the intercostal muscles dimensional changes responsible for increasing thoracic capa Learning Objective 10: Application Name and describe the structures moving the thoracic wall and explain how they assist the diaphragm with inhalation and exhalation. Ask yourself: • Name 3 accessory muscles of respiration that can assist with inhalation. • Name an accessory muscle of respiration that will pull the rib cage inferiorly, thus assisting with exhalation. • What is the functional role of the intercostal muscles during respiration? Learning Objectives 11. Identify the items provided on the structure checklist for this session.