The obturator nerve in human anatomy arises from the ventral divisions of the second, third, and fourth lumbar nerves in the lumbar plexus ; the branch from the third is the largest, while that from the second is often very small.
Structure
The obturator nerve originates from the anterior divisions of the L2 , L3 , and L4 spinal nerve roots .[1] psoas major , and emerges from its medial border near the brim of the pelvis . It then passes behind the common iliac arteries , and on the lateral side of the internal iliac artery and vein, and runs along the lateral wall of the lesser pelvis , above and in front of the obturator vessels , to the upper part of the obturator foramen .
Here it enters the thigh, through the obturator canal , and divides into an anterior and a posterior branch, which are separated at first by some of the fibers of the obturator externus , and lower down by the adductor brevis .[2]
An accessory obturator nerve may be present in approximately 8% to 29% of the general population.[3]
Branches
Function
The obturator nerve is responsible for the sensory innervation of the skin of the medial aspect of the thigh .
The nerve is also responsible for the motor innervation of the adductor muscles of the lower limb (external obturator ,[4] adductor longus , adductor brevis , adductor magnus , gracilis ) and the pectineus (inconstant). It is, notably, not responsible for the innervation of the obturator internus , despite the similarity in name.[5]
Clinical significance
An obturator nerve block may be used during knee surgery and urethral surgery in combination with other anaesthetics .[6]
This article incorporates text in the public domain from page 953 of the 20th edition of Gray's Anatomy (1918)
^ Weiss, Lyn; Silver, Julie K.; Lennard, Ted A.; Weiss, Jay M. (2007-01-01), Weiss, Lyn; Silver, Julie K.; Lennard, Ted A.; Weiss, Jay M. (eds.), "Chapter 6 - Nerves" , Easy Injections , Philadelphia: Butterworth-Heinemann, pp. 105–155, ISBN 978-0-7506-7527-7 , retrieved 2021-01-06 ^ "The Obturator Nerve - Course - Motor - Sensory - TeachMeAnatomy" .^ Turgut, Mehmet; Protas, Matthew; Gardner, Brady; Oskoui̇an, Rod J.; Loukas, Marios; Tubbs, R. Shane (2017-12-15). "The accessory obturator nerve: an anatomical study with literature analysis" . Anatomy . 11 (3): 121–127. doi :10.2399/ana.17.043 ^ Moore, K.L., & Agur, A.M. (2007). Essential Clinical Anatomy: Third Edition. Baltimore: Lippincott Williams & Wilkins. 336. ISBN 978-0-7817-6274-8
^ Moore, K.L., & Agur, A.M. (2007). Essential Clinical Anatomy: Third Edition. Baltimore: Lippincott Williams & Wilkins. 345. ISBN 978-0-7817-6274-8
^ Rea, Paul (2015-01-01), Rea, Paul (ed.), "Chapter 3 - Lower Limb Nerve Supply" , Essential Clinically Applied Anatomy of the Peripheral Nervous System in the Limbs , Academic Press, pp. 101–177, doi :10.1016/b978-0-12-803062-2.00003-6 , ISBN 978-0-12-803062-2 , retrieved 2021-01-06 
