Brachial Plexus Lecture 2 PDF

(BRACHIAL PLEXUS) It is a collection of nerves that lie partly in the axilla and partly in the neck. Roots of brachial plexus: Ventral (anterior) primary rami of C5,6,7,8 & Tl nerves. Trunks of brachial plexus: Upper trunk (union of C5 & C6 roots). Middle trunk (continuation of C7 root). Lower trun...

(BRACHIAL PLEXUS) It is a collection of nerves that lie partly in the axilla and partly in the neck. Roots of brachial plexus: Ventral (anterior) primary rami of C5,6,7,8 & Tl nerves. Trunks of brachial plexus: Upper trunk (union of C5 & C6 roots). Middle trunk (continuation of C7 root). Lower trunk (union of C8 & T1 roots). Divisions of brachial plexus: Each trunk divides (behind clavicle) into anterior & posterior divisions. Cords of brachial plexus: Lateral cord: union of anterior divisions of upper & middle trunks. Medial cord: anterior division of lower trunk. Posterior cord: union of posterior divisions of the 3 trunks. Branches of brachial plexus: Root: (1) Dorsal scapular n. (C5). (2) Long thoracic n. (C5,6,7). (3) Branch to phrenic n. (C5). (4) Twigs to scalenus & longus coli muscles. Upper trunk: (1) Suprascapular n. (C5,6). (2) N. to subclavius (C5,6). Lateral cord: (1) Lateral pectoral n. (C5,6,7). (2) Lateral root of median n. (C5,6,7). (3) Musculocutaneous n. (C5,6,7). Medial cord: (1) Medial pectoral n. (C8,T1). (2) Medial root of median n. (C8,T1). (3) Ulnar n. (C7,8,TI). (4) Medial cutaneous n. of arm (C8,T1). (5) Medial cutaneous n. of forearm (C8,T1). Posterior cord: (1) Radial n. (C5,6,7,8,T1). (2) Axillary n. (C5,6). (3) Upper subscapular n. (C5,6). (4) Lower subscapular n. (C5,6). (5) Thoracodorsal n. (C6,7,8). (SKIN OF UPPER LIMB) Cutaneous nerve supply: 1. Supraclavicular n. (C3,4): branch of cervical plexus. It supplies skin over the upper half of deltoid (shoulder region). 2. Upper lateral cutaneous n. of arm (C5,6): branch of axillary n. It supplies skin. over the lower half of deltoid (shoulder region). 3. Lower lateral cutaneous n. of arm (C5,6): branch of radial n. It supplies skin of lateral side of arm (below deltoid). 4. Intercostobrachial n. (T2): it is the lateral branch of second intercostal n. It supplies skin of upper part of medial side of arm (close to axilla).  5. Medial cutaneous n. of arm (C8,T1): branch of medial cord of brachial plexus. It supplies skin of medial side of arm (below axilla). 6. Posterior cutaneous n. of arm (C5,6,7,8,T1): branch of radial n. It supplies skin of back of arm (from deltoid tuberosity to elbow). 7. Posterior cutaneous n. of forearm (C5,6,7,8): branch of radial n. It supplies skin of back of forearm (from elbow to wrist). 8. Medial cutaneous n. of forearm (C8,T1): branch of medial cord of brachial plexus. It supplies skin of medial side of forearm. It divides into anterior & posterior branches. 9. Lateral cutaneous n. of forearm (C5,6): continuation of musculocutaneous n. It supplies skin of lateral side of forearm & skin over base of thenar eminence. It divides into anterior & posterior branches. 10. Palmar cutaneous branch of ulnar n. (C8,T1): supplies skin of medial third of the palm. 11. Palmar cutaneous branch of median n. (C6,7,8): supplies skin of lateral two- thirds of the palm. 12. Dorsal cutaneous branch of ulnar n. (C8,T1): supplies skin of medial third of back of hand. 13. Super cial branch of radial n. (C6,7,8): supplies skin of lateral two-thirds of back of hand. 14. Palmar digital branch of ulnar n. (C8,T1): supplies skin of palmar side of medial one & a half ngers, also the skin over back of distal & middle phalanges of medial one & a half ngers. 15. Dorsal digital branch of ulnar n. (C8,T1): supplies skin over back of proximal phalanx of medial one & a half ngers. 16. Palmar digital branch of median n. (C6,7,8): supplies skin over palmar side of lateral three & a half ngers, also the skin over back of distal & middle phalanges of lateral three & a half ngers (distal phalanx only in thumb). 17. Dorsal digital branch of radial n. (C6,7,8): supplies skin over back of proximal phalanx of lateral three & a half ngers. fi fi fi fi fi fi fi  (SUPERFICIAL FASCIA OF UPPER LIMB) Super cial fascia of upper limb contains the super cial veins & lymphatics. (VEINS OF UPPER LIMB) 1. Super cial veins: Dorsal venous arch: It lies in super cial fascia of dorsum of hand (distally). It receives 3 dorsal metacarpal veins (which are formed by union of dorsal digital veins). It gives: (1) basilic v. medially. (2) cephalic v. laterally. Basilic v.: Formed by union of medial end of dorsal venous arch & medial dorsal digital v. of little nger. It ascends along medial side of forearm then the medial side of arm where it pierces deep fascia at the middle of arm. It ends at lower border of teres major as it continues as axillary v. fi fi fi fi fi Cephalic v.: Formed by union of lateral end of dorsal venous arch & dorsal digital veins of thumb & lateral dorsal digital v. of index nger. It ascends along lateral side of forearm & arm, entering into deltopectoral groove, piercing the clavipectoral fascia. It ends by draining into axillary v. Note: At cubital fossa, basilic & cephalic veins are joined by median cubital v. 2. Deep veins: Axillary v.: It lies under deep fascia (in axilla). It begins as a continuation of basilic v. at lower border of teres major. It ends by becoming subclavian v. at lateral (outer) border of rst rib. Its lateral relation is axillary a. & its medial relation is apical & lateral axillary lymph nodes. Tributaries of axillary v. correspond to the 6 branches of axillary a., in addition to cephalic v., basilic v. & two venae comitantes. fi fi