Lecture 8- Diaphragm and nerves of the thorax Flashcards
At what vertebral level does the IVC, oesophagus and aorta pierce the diaphragm?
IVC @T8
Oesophagus @T10
Aorta @T12
What is the diaphragm? What side is higher?
A 2x dome broad muscle the extends high into the thorax, protecting the liver and spleen. The right side is slightly higher due to the liver
What are the ligaments of the diaphragm from lateral to medial?
Lateral arcuate ligament
medial arcuate ligament
median arcuate ligament
Muscular sling
also called ‘eosophageal hiatus’. A hole in the diaphragm @T10 within the right crus, that the oesophagus and vagus nerve(ant/post vagal trunks, PS supply) pass through. During inspiration the sling tightens and acts as a functional sphincter that prevents regurgitation.
Central tendon, what is it and what passes through
Where the left and right crus meet. @T8 the IVC and right phrenic nerve pass through
Left and Right phrenic nerve
Left: Pierces left crus
Right: Pierces same opening as IVC, spreads out to supply RHS of diaphragm
Vagus nerves
PS supply to thorax, forms plexus on oesophagus
Sympathetic branches come from?
T1-L2
T1-T5 supplies cardiac and pulmonary
Referred pain of the phrenic nerve
If the phrenic nerve is irritated, you’ll feel it in your shoulder (C3, C4, C5) even though the source is usually interabdominal space.
Horners Syndrome Symptoms
Ptosis: eyelids droop, control is lost
Miosis: pupils constricts, not reactive to light
Anhidrosis: Inability to sweat on one side of the face, very dry
Ptosis and miosis occurs in the same eye
Causation of Horners Syndrome
Due to sympathetic fibre damage or compression. This could be an abdominal tumor compressing sympathetic chains, altering info to head & neck
What does it mean if one side of the diaphragm is really high
Could be damage to the phrenic nerve during surgery.
As the diaphragm contracts it descends down, if damaged it cant do this, it will stay high > lopsided appearance.
