Anatomy
Origin:
Spinous processes of T11 to L3 and supraspinous ligaments.
Insertion:
Lower border of the 9th to the 12th ribs just lateral to their angles.
Key Relations:
-Serratus posterior inferior shares it’s aponeurosis of origin with latissimus dorsi.
-Sometimes referred to as part of the respiratory group.
Functions
-Depresses 9th to the 12th ribs, aiding in forced expiration.
-May prevent elevation of the lower ribs when the diaphragm contracts.
Supply
Nerve Supply:
Anterior rami of T9 to T12 i.e. intercostals nerves 9 to 12.
Blood Supply:
Intercostal arteries.
Interested in taking our award-winning Pocket Anatomy app for a test drive?
