Brachial plexus consists of Roots (C5–T1), Trunks (upper, middle, lower), Divisions (each trunk splits into anterior/posterior), Cords (lateral, posterior, medial), and terminal Branches (musculocutaneous, axillary, radial, median, ulnar). Anatomical course: roots emerge between scalene muscles; trunks in posterior triangle; divisions under clavicle; cords encircle axillary artery and give off named nerves (e.g. lateral cord → musculocutaneous). Key relationships: the long thoracic nerve (C5-7) arises from roots (winged scapula if injured); axillary nerve from posterior cord (risk in shoulder dislocation); radial nerve from posterior cord (mid-shaft humerus fracture → wrist drop). Injury patterns: Upper plexus (Erb’s palsy, C5-6) causes arm adducted/internally rotated ('waiter’s tip'); Lower plexus (Klumpke’s, C8-T1) causes hand paralysis and Horner syndrome if sympathetic chain involved. Examination: look for motor deficits by peripheral nerve distribution (e.g. loss of shoulder abduction suggests axillary nerve/C5 injury) and sensory deficits (e.g. lateral forearm numbness indicates musculocutaneous nerve). Imaging: MRI or nerve conduction studies help localize root avulsions vs stretch injuries. Management ranges from physical therapy for neuropraxia to nerve grafts/transfers for severe root avulsions.
Introduction Monteggia fracture refers to a fracture of the proximal or middle third of the ulna associated with dislocation of the radial head a...
Case Presentation A 28-year-old male presented to the emergency department following a road traffic accident with severe pain and deformity of th...
Case Presentation A young male presented with severe wrist pain following a motorcycle accident 3 days ago. The mechanism involved a fall on an o...
What is the root value of the long thoracic nerve?
Which nerve is primarily affected in Erb's palsy?
Which of the following nerves is a terminal branch of the lateral cord of the brachial plexus?
In a mid-shaft humeral fracture, which nerve is most likely to be injured, leading to wrist drop?
What is the primary function of the axillary nerve?
Which condition is associated with lower trunk injury of the brachial plexus?
Which of the following is NOT a branch of the posterior cord of the brachial plexus?
Which part of the brachial plexus is located in the posterior triangle of the neck?
What anatomical structure do the cords of the brachial plexus encircle?
Which nerve is responsible for sensory innervation of the lateral forearm?
