Psoas minor muscle

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
Psoas minor muscle
Musculus psoas minor.png
Muscles of the iliac and anterior femoral regions (psoas minor visible near top right)
Details
OriginLateral surface bodies of T12 and L1 vertebrae and intervening intervertebral disc
InsertionPectineal line and iliopubic eminence
NerveAnterior ramus of nerve L1
ActionsWeak trunk flexor
AntagonistErector Spinae
Identifiers
LatinMusculus psoas minor
MeSHD016658
TAA04.7.02.005
FMA22350
Anatomical terms of muscle

The psoas minor is a long, slender skeletal muscle which, when present, is located anterior to the psoas major muscle.[1][2]

Structure[edit]

Psoas minor originates from the vertical fascicles inserted on the last thoracic and first lumbar vertebrae. From there, it passes down onto the medial border of the psoas major, and is inserted to the innominate line and the iliopectineal eminence. Additionally, it attaches to and stretches the deep surface of the iliac fascia and occasionally its lowermost fibers reach the inguinal ligament.[3] Variations occur, however, and the insertion on the iliopubic eminence sometimes radiates into the iliopectineal arch.[4]

It arises from the sides of the bodies of the twelfth thoracic and first lumbar vertebrae and from the intervertebral discs separating them. It ends in a long flat tendon which is inserted into the pectineal line and iliopectineal eminence, and, by its lateral border, into the iliac fascia.[citation needed]

The psoas minor is supplied by the four lumbar arteries (inferior to the subcostal artery) and the lumbar branch of the iliolumbar artery.[citation needed]

Variation[edit]

The psoas minor is considered inconstant and is often absent, only being present in about 40% of human specimens studied.[5] It has an average length of about 24 cm, of which about 7.1 cm is muscle tissue and about 17 cm is tendon.

Function[edit]

The psoas minor is a weak flexor of the lumbar vertebral column.

Additional images[edit]

Notes[edit]

  1. ^ Tank (2005), p 93
  2. ^ Gray (2008), p 1372
  3. ^ Bendavid (2001), p 58
  4. ^ Platzer (2004), p 234
  5. ^ Mcg Farias (1 Jan. 2012). Morphological and morphometric analysis of Psoas Minor Muscle in cadavers. ResearchGate. Retrieved from https://www.researchgate.net/publication/280236296_Morphological_and_morphometric_analysis_of_Psoas_Minor_Muscle_in_cadavers

References[edit]

  • Bendavid, Robert; Abrahamson, Jack; Arregui, Maurice E. (2001). Abdominal Wall Hernias: Principle and Management. Springer. ISBN 0-387-95004-4.
  • Platzer, Werner (2004). Color Atlas of Human Anatomy, Vol 1: Locomotor system (5th ed.). Thieme. ISBN 3-13-533305-1. (ISBN for the Americas 1-58890-159-9.)
  • Tank, Patrick W. (2005). Grant's Dissector (13th ed.). Hagerstown, MD: Lippincott Williams & Wilkins. ISBN 0-7817-5484-4.
  • Gray, Henry; Standring, Susan (2008). Gray's Anatomy - The Anatomical Basis of Clinical Practice (40th ed.). Churchill Livingstone - Elsevier. ISBN 978-0-443-06684-9.