W3 organization of brachial plexus and nerve paths Flashcards
• Brachial plexus
o Somatic plexus
o Formed by anterior rami of C5, C6, C7, C8, T1
o Begins in neck passes laterally and inferiorly over rib 1 into the axilla and associates with the axillary artery
o From proximal to distal form roots, trunks, divisions, cords, terminal branches
• Lateral cord
o Made from C5 and C6 roots o Made from upper trunk o Divisions from upper and middle o Forms musculocutaneous and combines with medial cord to make median nerve o Cord forms lateral pectoral nerve
• Posterior cord
o Made from C7 root
o Middle trunk
o With divisions from lateral and medial
o Makes axillary and radial nerve
o Cord makes upper and lower subscapular nerve and thoracodorsal nerve
• Medial cord
o Made from C8 and T1 roots
o Lower trunk
o Makes ulnar nerve and combines with lateral cord to make median nerve
o Cord makes medial pectoral never and medial cutaneous nerves of the arm and forearm
• Dorsal scapular
o Made from C5 and C6 roots
• Suprascapular nerve
o Formed from the upper trunk
o Trunk is made from C5 and C6
• Long thoracic nerve
o Made from C5 and C7 roots
• Axillary sensory
o Shoulder
• Radial nerve sensory
o Lateral arm
• Medial brachial cutaneous nerve sensory
o Medial cord
o Medial arm
• Lateral antebrachial cutaneous nerve sensory
o Musculocutaneous
o Lateral forearm
• Medial antebrachial cutaneous nerve sensory
o Medial cord
o Medial forearm
• Median nerve sensory
o Medial lateral hand
o Finger tips
• Ulnar nerve sensory
o Medial hand
• Lateral antebrachial cutaneous nerve sensory
o Lateral posterior forearm
• Radial nerve sensory
o Lateral distal forearm
• Musculocutaneous nerve path
o Terminal branch of lateral cord
o Immediately enters anterior compartment of arm and runs between brachialis and biceps brachii muscles
• Median nerve path
o Terminal branch of lateral and medial cords
o Axilla and runs distal with brachial artery in the medial arm
o Crosses anterior to elbow joint and enters forearm
o In upper forearm, gives off deep branch (anterior interosseous nerve) and continues into hand through carpal tunnel
• Ulnar nerve path
o Terminal branch of medial
o Runs distally in association with brachial artery and median nerve in medial aspect of arm
o Passes posterior to medial epicondyle and enters forearm
o Travels medial forearm close to ulna and divides into superficial and deep branch at the wrist
• Axillary nerve path
o Terminal branch of posterior cord that exits in posterior axilla
o Passes posterior to surgical neck of humerus
• Radial nerve path
o Terminal branch of posterior cord
o Passes out of axillar into posterior compartment of the arm close to posterior aspect of the shaft of humerus
o Enters forearm posterior to lateral epicondyle of the humerus and travels to the posterior aspect of hand
o Through the forearm, gives off deep branch (posterior interosseous nerve)
