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Internal oblique
Other Terms:
Obliquus internus abdominis muscle,
Musculus obliquus internus abdominis,
Muscle oblique interne de l'abdomen
Muscle parts
None
Latin name
Musculus obliquus internus abdominis
Latin muscle parts
None
Group
Abdominal wall – lateral musculature – middle layer
Etymology
This muscle’s name in English is the within (middle) slanting muscle of the belly. The Latin term obliquus means slanting or sideways and describes its orientation.The Latin term internus means “within.”The word abdomen is of uncertain etymology. Two possible origins of this word are from the Latin abdere meaning “to stow away,” which the abdomen does to the digestive organs. The other possibility is that it comes from adipem meaning “fat.”
Origin
Lateral half of inguinal ligament, anterior portion of iliac crest, and thoracolumbar fascia
Insertion
Costal cartilages of lowest four ribs and linea alba
Action
Strong compressor of the abdominal cavity; rotates trunk to the same side; weakly assists in flexion of lumbar vertebrae
Nerve supply
Intercostal nerves (T7 to T11), subcostal nerve (T12), and iliohypogastric and ilioinguinal nerves (both from L1)
Blood supply
Numerous arteries supply and anastomose within this extensive muscle sheet including the superior and inferior epigastric arteries, posterior intercostal arteries from the three lowest rib spaces, the subcostal artery, the musculophrenic artery, superficial epigastric artery, superficial circumflex iliac artery, ascending branch of the deep circumflex iliac artery, lumbar arteries.
Latin
Musculus obliquus internus abdominis
French
Muscle oblique interne de l'abdomen