##Diaphragm##
- Describe the attachments, nerve supply and actions of diaphragm
- Attachments:
- Right and left crura (costal and lumbar parts) to bodies of L1-L3 vertebrae
- Xiphoid process and central tendon
- Nerve supply:
- Ventral rami of C3-C5 nerves (phrenic nerve)
- Right and left vagus nerves
- Actions:
- Inspiration → descends, increases thoracic cavity volume
- Expiration → ascends, decreases thoracic cavity volume
- Mention the major openings in the diaphragm and structures passing through it
- Openings:
- Aortic hiatus (T12 vertebra) → Aorta, thoracic duct, and azygos vein
- Esophageal hiatus (T10 vertebra) → Esophagus and vagus nerves
- Caval opening (T8 vertebra) → Inferior vena cava
- Phrenic and pericardial openings
- Structures passing through:
- Thoracic duct
- Azygos vein
- Aorta
- Esophagus
- Vagus nerves
- Describe the nerve and blood supply
- Nerve supply:
- Ventral rami of C3-C5 nerves (phrenic nerve)
- Right and left vagus nerves
- Blood supply:
- Superior phrenic artery
- Inferior phrenic arteries
- Musculophrenic artery
- Describe its applied anatomy
- Clinical relevance:
- Diaphragmatic hernia (hiatal hernia)
- Diaphragmatic paralysis
- Diaphragmatic rupture
- Surgical relevance:
- Laparoscopic procedures
- Thoracic surgery
Developmental Process
- Diaphragm develops from pleuroperitoneal membranes and septum transversum → step 1: Pleuroperitoneal membranes form between pleura and peritoneum → step 2: Septum transversum forms between pleura and peritoneum → step 3: Pleuroperitoneal membranes and septum transversum fuse to form diaphragm
Applied Anatomy
- Diaphragmatic breathing: used in CPR and respiratory therapy
- Diaphragmatic hernia: surgical repair of diaphragmatic defect
- Thoracic surgery: diaphragmatic incision or resection may be required