|Origin||Pectineal line of the pubic bone|
|Insertion||Pectineal line of the femur|
|Nerve||Femoral nerve, sometimes obturator nerve|
|Actions||Thigh - flexion, adduction, internal rotation|
|Anatomical terms of muscle|
The pectineus muscle (//, from the Latin word pecten, meaning comb) is a flat, quadrangular muscle, situated at the anterior (front) part of the upper and medial (inner) aspect of the thigh. The pectineus muscle is the most anterior adductor of the hip. The muscle does adduct and internally rotate the thigh but its primary function is hip flexion.
The pectineus muscle arises from the pectineal line of the pubis and to a slight extent from the surface of bone in front of it, between the iliopectineal eminence and pubic tubercle, and from the fascia covering the anterior surface of the muscle; the fibers pass downward, backward, and lateral, to be inserted into the pectineal line of the femur which leads from the lesser trochanter to the linea aspera.
The pectineus is in relation by its anterior surface with the pubic portion of the fascia lata, which separates it from the femoral artery and vein and internal saphenous vein, and lower down with the profunda artery.
By its internal border with the outer edge of the adductor longus.
It forms part of the floor of the femoral triangle.
The lumbar plexus is formed from the anterior rami of nerves L1 to L4 and some fibers from T12. With only five roots and two divisions, it is less complex than the brachial plexus and gives rise to a number of nerves including the femoral nerve and accessory obturator nerve. The pectineus muscle is considered a composite muscle as the innervation is by the femoral nerve (L2 and L3) and occasionally (20% of the population) a branch of the obturator nerve called the accessory obturator nerve. When it is present, the accessory obturator nerve innervates a portion of the pectineus muscle, entering the muscle on its dorsomedial aspect. The greater nerve to the muscle is the femoral nerve. Unlike the obturator accessory nerve, the femoral nerve is always present and provides the sole innervation for the pectineus muscle in over 90% of cases. The muscle is also innervated by the accessory obturator nerve in the 8.7% of cases in which the nerve occurs.
- Mosby's Medical, Nursing & Allied Health Dictionary, Fourth Edition, Mosby-Year Book Inc., 1994, p. 1177
- Ellis, Harold; Susan Standring; Gray, Henry David (2005). Gray's anatomy: the anatomical basis of clinical practice. St. Louis, Mo: Elsevier Churchill Livingstone. p. 518. ISBN 0-443-07168-3.
- medialthigh at The Anatomy Lesson by Wesley Norman (Georgetown University)
- Wilson, Erasmus (1851). The anatomist's vade mecum: a system of human anatomy. John Churchill. p. 260.
- Woodburne, Russell (1960). "The Accessory Obturator Nerve and the Innervation of the Pectineus Muscle" (PDF). Michigan Library Med School. 136 (3): 367–369. doi:10.1002/ar.1091360303. hdl:2027.42/49789. PMID 13845846. S2CID 14846721. Retrieved 2 December 2015.
- Saladin, Kenneth S. Anatomy & Physiology: The Unity of Form and Function. New York, NY: McGraw-Hill, 2007. pg.493. Print.
- Anatomy figure: 12:02-05 at Human Anatomy Online, SUNY Downstate Medical Center - "Muscles of the anterior (extensor) compartment of the thigh."
- Anatomy figure: 12:03-04 at Human Anatomy Online, SUNY Downstate Medical Center - "Deep muscles of the anterior thigh."
- Cross section image: pelvis/pelvis-e12-15—Plastination Laboratory at the Medical University of Vienna