D I a p h r a g m
DiaphragmSeparates the thoracic and abdominal cavities.
Number of openings to allow passage of structures between thoracic and abdominal cavities.
Largest openings for esophagus, aorta and inferior vena cava
Only muscle that must contract for quiet, relaxed inspiration.
Usually under both conscious and unconscious control.
Innervations is phrenic nerve composed of spinal nerves
C3, 4, 5.
“C3, 4, 5 keeps the diaphragm alive!”
Clinically a Hiatal hernia is when part of the stomach herniated through the diaphragm into the thoracic cavity.
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Diaphragm
Origen: Internal surfaces of ribcage, sternum and spineInsertion: Central tendon of diaphragm
Action: Increases volume of thoracic cavity during inspiration
Nerve supply: Phrenic nerve
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• Central tendon
• Sternal origin• Costal origin
• Lumbar origin• Sternocostal triangle
• Lumbocostal triangle3 Hiatus
Vena cava foramen: inferior vena cava ( vertebrae VIII & IX)
Esophageal hiatus: esophagus, vagus nerve (vertebrae X )
Aortic hiatus: aorta, thoracic duct, azygos vein, hemiazygos vein (vertebrae XII )
• aorta
• esophagus• Inferior vena cava
• thoracic aorta
• Esophageal• hiatus
• Vena caval foramen
Blood Vessels
Superior Surface:Pericardiophrenic artery
Musculophrenic artery
Superior Phrenic artery
Inferior Surface:
Inferior phrenic arteries
Veins
Correspond to the arteries• Internal thoracic artery
• Abdominal aorta
• Superior & inferior vena cava
Thoracic aortaLymphatic Drainage
• Phrenic lymph nodes• Parasternal & posterior mediastinal lymph nodes
• Phrenic nerves
• Cervical plexus ( C3-C5 )
Innervation