Anatomy of the brachial plexus

Stoyan Pavlov, MDDepartment of anatomy, histology and embryology,

University of Medicine “Prof. Dr. Paraskev Stoyanov”, Varna

Plexus Brachialis

Responsible for the motor and most of the sensitive innervation of the upper limb.

Derived from the main anterior branches of C5-C8 and Th1spinal nerves.

Small branches from C4 and/or Th2 contribute to the plexus

C5C6C7C8Th1

Supraclavicular part = Trunks: Truncus superior - C5 and C6; Truncus medius – C7; Truncus inferior - C8 and Th1.

Behind the clavicle: Anterior and posterior divisions of the trunks.

Infraclavicular part = Cords:Fasciculus lateralis;Fasciculus medialis Fasciculus posterior

Plexus brachialisScalenus anterior

Scalenus medius

Nerves of the supraclavicular part

N. dorsalis scapulae (C5)

N. thoracicus longus (C5-7)

N. suprascapularis (C5,6)

Nerves of the infraclavicular part

Nn. pectorales lateralis (C5-7) et medialis (C8,Th1)

Nn. subscapulares (C5,6)

N. thoracodorsalis (C6-8)

Nn. pectorales lateralis et medialis

N. thoracodorsalis

Nn. subscapulares

N. radialisN. ulnaris

N. medianus

N. musculocutaneus

N. radialis

N. axillaris

N. medianus

N. radialis

N. medianus

N. ulnaris

R. superficialis n. radialis

R. profundus n. radialis

R. palmaris n. ulnaris

N. medianus

Only 65% of the plexuses are build according the described plan.

Only about 60% of the brachial plexuses are symmetrical.

Segmental cutaneous innervation of the upper limb(There is considerable overlap of the cutaneous

segments)

Upper Shoulder Region C3,4 (supraclavicular nerves of the cervical plexus)

Deltoid Region and Lateral Aspect of the Arm

C5

Lateral Forearm and Thumb C6

Hand and Middle Three Fingers C7

5th Finger and Medial Side on the Hand, Lower Forearm

C8

Medial Side of the Lower Arm and Upper Forearm

T1

Upper Arm on its Medial Side T2 (via the intercostobrachial nerve)

Segmental innervation of the muscles of the upper limb(by affected joints )Shoulder

Abductors and Lateral Rotators C5Adductors and Medial Rotators C6,7, 8Elbow

Elbow Flexors C5,6Elbow Extensors C7, 8 Forearm

Pronators and Supinators of the Forearm. C6Wrist

Long Flexors and Extensors of the Wrist. C6,7Hand

Long Flexors and Extensors of the Fingers. C7,8Intrinsic Muscles of the Hand. T1