2.2.2
11
Infraclavicular part of the brachial plexus
Posterior cord
• 1 Axillary nerve (nervus axillaris) – C5–C6
Course – passes with the posterior circumflex humeral artery and veins through the humerotricipital foramen to the posterior part of the surgical neck of the humerus Branches and structures innervated: 1.1 Muscular branches (rami musculares) – innervate the deltoid and teres minor muscles 1.2 Articular branches (rami articulares) – sensory innervation for a part of the shoulder joint capsule 1.3 Superior lateral cutaneous nerve of arm / superior lateral brachial cutaneous nerve (nervus cutaneus brachii lateralis superior) – sensory innervation of the skin of the deltoid region
• 2 Radial nerve (nervus radialis)
1
– C5–C8 and an additional branch from T1 2 Course 1. spirals down the radial canal (a space bound by the groove for the radial nerve and the medial and lateral heads of the triceps brachii on the posterior surface of the humerus) 2.4 with the deep brachial artery and veins 2. perforates the lateral intermuscular septum to enter the anterior compartment of the arm, where it travels 2.1 between brachialis and the brachioradialis 3. runs through the cubital fossa, where it divides into the superficial and deep branches 4. the deep branch enters the dorsal forearm through the supinator canal (a space between two heads of the supinator) 2.5 5. the superficial branch runs with the radial artery and veins to the radial fossa, where it divides into somatosensory branches for the dorsum of the hand Branches and structures innervated: 2.1 Muscular branches in the arm (rami musculares) 2.7 – innervate the triceps brachii and anconeus 2.2 Muscular branches in the forearm (rami musculares) – innervate all posterior and lateral muscles of the forearm 2.3 Inferior lateral cutaneous nerve of arm / Inferior lateral brachial cutaneous nerve (nervus cutaneus brachii lateralis inferior) – sensory innervation of the distal part of the deltoid region 2.6 and lateral part of the arm 2.4 Posterior cutaneous nerve of arm / posterior brachial cutaneous nerve (nervus cutaneus brachii posterior) 2.6.1 – sensory innervation of the posterior side of the arm 2.5 Posterior cutaneous nerve of forearm / posterior antebrachial cutaneous nerve (nervus cutaneus antebrachii posterior) – sensory innervation of the posterior side of the forearm 2.6 Superficial branch (ramus superficialis) – branches from the radial nerve in the cubital fossa and travels with the radial vessels Right upper limb, forearm in pronation 2.6.1 Dorsal digital nerves (nervi digitales dorsales) – sensory innervation of the thumb and forefinger and the radial side of the 3rd finger (proximal and middle phalanges only) 2.7 Deep branch (ramus profundus) – runs through the supinator canal to get to the posterior compartment of the forearm, where it passes between the deep and superficial layers, giving off muscular branches 2.7.1 Posterior interosseous nerve (nervus interosseus antebrachii posterior) – runs on the posterior side of the interosseous membrane of the forearm with the posterior interosseous vessels – innervates the periosteum of both the radius and ulna, the interosseous membrane and both radio-ulnar joints
1.3 1.3
2.3
2.4
2.5
2.6.1
2.6.1
Skin innervation of arm, forearm and hand
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