Pectineus muscle

Pectineus
The pectineus and nearby muscles
Structures passing behind the inguinal ligament (pectineus visible at bottom right.)
Details
Latin	Musculus pectineus
Origin	Pectineal line of the pubic bone
Insertion	Pectineal line of the femur
Artery	Obturator artery
Nerve	Femoral nerve, sometimes obturator nerve
Actions	Thigh - flexion, adduction
Identifiers
Dorlands /Elsevier	m_22/12550120
TA
TH	{{#property:P1694}}
TE	{{#property:P1693}}
FMA	{{#property:P1402}}
Anatomical terms of muscle [[[d:|edit on Wikidata]]]

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 medially rotate the thigh but its primary function is hip flexion.

It can be classified in the medial compartment of thigh (when the function is emphasized) or the anterior compartment of thigh (when the nerve is emphasized).

Structure

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.

Relations

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 posterior surface with the capsule of the hip joint, and with the obturator externus and adductor brevis, the obturator artery and vein being interposed.

By its external border with the psoas major, the femoral artery resting upon the line of interval.

By its internal border with the outer edge of the adductor longus.

Obturator hernia is situated directly behind this muscle, which forms one of its coverings.

Innervation

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.

Function

It is one of the muscles primarily responsible for hip flexion. It also adducts the thigh.

Additional images

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  Right hip bone. External surface.

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  Structures surrounding right hip-joint.

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  Muscles of the iliac and anterior femoral regions.

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  Deep muscles of the medial femoral region.

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  The left femoral triangle.

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  The lumbar plexus and its branches.

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  Pectineus muscle

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  Pectineus muscle

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  Pectineus muscle

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  Pectineus muscle

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  Pectineus muscle

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  Muscles of Thigh. Anterior views

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  Muscles of Thigh. Anterior views.

See also

This article uses anatomical terminology; for an overview, see Anatomical terminology.

• Thigh

References

This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)

http://deepblue.lib.umich.edu/bitstream/handle/2027.42/49789/1091360303_ftp.pdf?sequence=1

Saladin, Kenneth S. Anatomy & Physiology: The Unity of Form and Function. New York, NY: McGraw-Hill, 2007. pg.493. Print.

External links

• -1301610416 at GPnotebook
• 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