Diaphragm Lecture PDF 2024

Anatomy of the Diaphragm Prof. Mohammed Z. Allouh Recommended Textbooks & Atlases (Notice: images included in this presentation are adapted from these recommended textbooks and atlases) Clinical Anatomy by Regions, 9th ed. Richard S....

Anatomy of the Diaphragm Prof. Mohammed Z. Allouh Recommended Textbooks & Atlases (Notice: images included in this presentation are adapted from these recommended textbooks and atlases) Clinical Anatomy by Regions, 9th ed. Richard S. Snell. Copyright © 2012 Wolters Kluwer/Lippincott Williams & Wilkins. Moore Clinically Oriented Anatomy, 7th ed. Keith Moore, Arthur Dalley, & Anne Agur. Copyright © 2014 Wolters Kluwer/Lippincott Williams & Wilkins Gray’s Anatomy for Students, 4th ed. Richard L. Drake, A. Wayne Vogl, Adam W. M. Mitchell. Copyright © 2020 Elsevier Inc. Grant’s Atlas of Anatomy, 13th ed. Anne M. R. Agur, Arthur F. Dalley. Copyright © 2013 Wolters Kluwer Health / Lippincott Williams & Wilkins.  Diaphragm A thin musculotendinous sheet that separates the thoracic cavity from the abdominal cavity (chief muscle of respiration) Upper surface : Convex, faces thorax Inferior surface: Concave, faces ?? abdomen Elevated bilateral domes: Lf. & Rt. Depressed central part: Because the ?? Lies on it Heart  Shape of the Diaphragm 2 domes: Right: upper border of 5th rib (why?) Liveronthe RIGHT SIDE Supports Rt. lung pericq.iqeaenic Left: 5th intercostal space I Supports Lf. lung insertionofdiaphragm Central Tendon: 3 leaves shape Leaf leaf Ta At xiphisternal joint Supports the heart (central leaf) Merges with fibrous pericardium Perforated by IVC  Peripheral Origin of the Diaphragm divides Divides into 3 parts anteriorly 1- Sternal origin: 2 muscle slips from post. Surface of xiphoid process 2- Costal origin: laterally wide slips from the inner surfaces of  6 CC & ribs (costal margin + 11 & 12)  forms domes posteriorly tight 3- Lumbar (Vertebral) origin: 2 divisions; 1,23  from  3 lumbar vertebrae  forms 2 crura (legs)  From condensations of fibrous fascia  forms 3 arcuate ligaments arched median medial  eral Crura of the Diaphragm Crus: L, leg not impotent 2 vertical tendomuscular bands that arise from the ant. surfaces of bodies of upper 3 lumbar vertebrae and IV discs in between Right Crus: - Larger & longer than Lf. upper3 - From  ?? lumbar vertebrae 2 Ndiscsinbetween - Turns as a sling around the fents esophagus  esophageal hiatus Loweresophageal rightaross.no **When contracts, it constricts esophagus  lower esophageal sphincter physiologic sphincter has afunction  Crura of the Diaphragm Left Crus: - Shorter than Rt. 2 - From  ?? lumbar vertebrae - Lies to left of midline ill The 2 crura (Rt. & Lf.) are connected by midline arching fibers that cross ant. to the aorta These fibers are named: Median arcuate ligament This ligament contributes to formation  aortic hiatus (what level?) contraction of diaphragm does not affect  1 Chi we a ns fit Arcuate Ligaments of Diaphragm 1- Median arcuate ligament: (single) - between the 2 Crura in midline - ant. To ?? 2- Medial arcuate ligament: (paired) - Thickening of fascia covering ?? Muscle onmuscle - psoas extends: body ofMAL2 L 11  tip of transverse Process of L1 3- Lateral arcuate ligament: (paired) - Thickening of fascia covering ?? Muscle - extends: tip of transverse Process of L1  12th rib  Arterial Blood Supply to Diaphragm Superior Surface 1- Musculophrenic a.: ITA , most ant. Ant113 2- Pericardiophrenic a.: ITA, middle aspect Middle 3- Superior Phrenic a.: Thoracic aorta IVC most post. 1 Posterior View Inferior Surface 4- Inferior Phrenic a.: Direct branch from ??AbdominalAorta *largest artery supplying diaphragm efforta suppliesfibrous pericard middlepartofdiaphragm fromITA FITTA  Innervation to Diaphragm Motor 03,04 as Phrenic nerve (origin?) - Penetrates diaphragm to innervate it from below (from abdominal surface) - Passes through ? Sensory - Central part  phrenic n. - Periphery   6 IC & subcost. Ns **The sensory innervation of the diaphragm is actually to its covering structures. These are: Superiorly  Parietal Diaphragmatic pleura + fibrous pericardium Inferiorly  Parietal peritoneum phrenic Attendance  Diaphragmatic Apertures (Openings in the Diaphragm)  Diaphragmatic Apertures 1- Caval Opening - in the central tendon to the Rt. Side - At the vertebral level of T8 - transmits: IVC + Rt. Phrenic n. **Since in the tendon  does not close it widens  Facilitate flow back of bld. from abdomen into thorax  Diaphragmatic Apertures 2- Esophageal Hiatus a loop - in the Rt. Crus just immediately to left of midline - At the vertebral level of ?? Tio - transmits: 1- Esophagus 2- ant & post vagal trunks 3- esophageal branches of Lf. gastric a & v **Since in the Rt. crus  Closes when diaphragm contract  Constricts esophagus “Lower Esophageal Sphincter” Physiologic or Anatomic Sphincter?  Diaphragmatic Apertures 3- Aortic Hiatus - Post. To Diaphragm, in midline exactly behind ?? Arcuate lig. median - At the vertebral level of ?? 12 - transmits: 1- Aorta 2- Thoracic duct (?) Largest lymph 3- Azygos vein vessels **Since posterior to diaphragm  Not affected by contractions of the Diaphragm  Additional Structures Passing through Diaphragm Additional 4 important structures: 1- Sup. Epigastric vessels:  Sterno-costal triangle Foramen of Morgagni f 2- Left phrenic nerve:  pierces the Left dome (Home work: At what vertebral level?) Ta  Additional Structures Passing through Diaphragm 3- Sympathetic trunks:  Posterior to medial arcuate lig. on each side r 4- Thoracic Splanchnic nerves:  pass through the Crura of diaphragm on each side (RtRt Crus , LfLf crus) Exception - Least splanchnic n.?  Review Caval Opening: 2? Esophageal Hiatus: 3? Aortic Hiatus: 3? 4 minor strs: Sup. epigastrics ? I Left Phrenic ?T9 Sympathetic trunks ?Posttomedial Splanchnic nerves ? Clinical Relations of the Diaphragm  Congenital Diaphragmatic Herniae (CDH) 1 Two types: 1- Morgagni’s hernia: Anterior in the foramen of Morgagni (Sternocostal triangle) 2- Bochdalek’s hernia: Posterolateral in the foramen of Bochdalek (Lumbocostal triangle) 2 More common than Morgagni’s hernia 85% on the left side. Liver  Hiccups Involuntary spasmodic contractions of the diaphragm  Causing sudden inhalations that interrupted by rapid closure of larynx  Resulting in a characteristic “hic” sound Cause: Irritations (excitations) of Phrenic nerve i.e. eating or drinking too much or too quickly  distension of the stomach  irritates phrenic nerev Common Examples: - In infants after milk feeding - After taking carbonated fizzy drinks (soft drinks)