<prompt> Long thoracic nerve supplies which of the following muscles?Serratus anteriorTeres minorSupraspinatusInfraspinatus  <response>: Ans. a Serratus anterior Ref. BDC Vol. I, 4th ed., 67LONG THORACIC NERVE OF BELL Derived from ventral rami of C5, C6, and C7 - close to their emergence from intervertebral foramina; It runs downward and passes either in front of or behind middle scalene muscle; It reaches upper slip of serratus anterior muscle and descends on outer surface of this muscle, giving branches into it; Scapular Winging: may occur from long thoracic nerve injury or from spinal accessory nerve injury which deinnervates the trapeziusSr.NerveMuscle GroupFunctional Deficit or Sign1.Long thoracicSerratus anterior Winging of scapula2.SuprascapularSupraspinatus and Infraspinatus Difficulty in initiating arm abduction3.AxillaryDeltoid and Teres minor Inability to fully abduct arm4.RadialExtensors of forearms, wrist proximal phalanges and thumb Loss of arm extension, loss of foreams extension, supination, abduction, loss of wrist extension wrist drop, loss of proximal phalangeal extension and thumb extension. Saturday night palsy.5.Musculocuta- neousFlexors of arm and forearm Weak arm and forearm flexion, weak forearm supination.6.MedianWrist and hand flexors Paralysis of flexor, pronator, and thenar muscles, inability to fully flex the index and middle fingers Sign of benediction, Pointing index finger, Labourers nerve, Ape-thumb deformity.7.UlnarWrist and hand flexors Musician nerve Inability to extend the distal and middle phalanges Clawhand; Loss of thumb abduction; Froment sign positive; Tardy ulnar palsy cubitus varus in condylar humerus fractureAlso know:Palsy of Median nerveMNEMONIC: SLAPFeaturesSign of benedictionLabourers nerveApe-thumb deformityPointing index fingerUlnar nerveFACTFroment signAbduction of thumb lostClaw handTardy palsy due to cubitus varus 