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WINDSOR UNIVERSITY SCHOOL OF MEDICINE St.Kitts. Dr. SREEKANTH THOTA. DEPARTMENT OF ANATOMY. UPPER LIMB. Upper Limb. The upper limb is divided into the shoulder (junction of the trunk with the arm), arm, elbow, forearm, wrist, and hand. How to study upper limb?. 1. Bones of the Upper Limb
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WINDSOR UNIVERSITYSCHOOL OF MEDICINESt.Kitts Dr. SREEKANTH THOTA DEPARTMENT OF ANATOMY UPPER LIMB
Upper Limb • The upper limb is divided into the shoulder (junction of the trunk with the arm), arm, elbow, forearm, wrist, and hand.
How to study upper limb? • 1. Bones of the Upper Limb • 2. Brachial Plexus • 3. Muscles of the Upper Limb a. Shoulder b. Arm c. Forearm d. Hand • 4. Blood vessels of upper limb • 5. Lymphatics of upper limb • 6. Joints of upper limb
Bones of the Upper Limb • Best way to learn bones of upper limb is during the anatomy lab, looking at Netter and follow your instructor.
Brachial Plexus • The brachial plexus is a somatic plexus formed by the anterior rami of C5 to C8, and most of the anterior ramus of T1. • It originates in the neck, passes laterally and inferiorly over rib I, and enters the axilla.
Brachial Plexus • All major nerves that innervate the upper limb originate from the brachial plexus, mostly from the cords. • The parts of the brachial plexus, from medial to lateral, are roots, trunks, divisions, and cords.
Brachial Plexus Injuries • Injuries to the brachial plexus affect movements and cutaneous sensations in the upper limb. • Signs and symptoms depend on the part of the plexus involved. • Injuries to the brachial plexus result in paralysis and anesthesia.
Branches of the Brachial Plexus • Roots: The roots of the brachial plexus are the anterior rami of C5 to C8, and most of T1. • 1. Dorsal scapular nerve (C5) • 2. Long thoracic nerve (C5, 6, and 7)
Trunks • In the inferior part of the neck, the roots of the brachial plexus unite to form three trunks • 1. Superior trunk, from the union of the C5 and C6 roots. • 2. Middle trunk, which is a continuation of the C7 root. • 3. Inferior trunk, from the union of the C8 and T1 roots. • The inferior trunk lies on rib I posterior to the subclavian artery; the middle and superior trunks are more superior in position.
Branches of the trunks • The only branches from the trunks of the brachial plexus are two nerves that originate from the superior trunk (upper trunk): • 1.Suprascapular nerve (C5 and 6) • 2.Nerve to the subclavius muscle (C5 and 6)
Divisions • Each of the three trunks of the brachial plexus divides into an anterior and a posterior division. • No peripheral nerves originate directly from the divisions of the brachial plexus.
Cords • The three cords of the brachial plexus originate from the divisions and are related to the second part of the axillary artery. • The anterior divisions of the upper and middle trunks unite to form the lateral cord, the anterior division of the lower trunk continues as the medial cord, and the posterior divisions of all three trunks join to form the posterior cord.
Branches of the lateral cord • 1.Lateral pectoral nerve(C5, 6, 7) • 2.Musculocutaneous nerve(C5, 6, 7) • 3.Lateral root of median nerve(C5, 6, 7)
Branches of the medial cord • 1.Medial pectoral nerve(C8; T1) • 2.Medial cutaneous nerve of arm (C8; T1) • 3.Medial cutaneous nerve of forearm(C8; T1) • 4.Ulnar nerve(C8; T1) • 5.Medial root of median nerve(C5, 6, 7, 8; T1)
Branches of the posterior cord • 1.Upper subscapular nerve(C5, 6) • 2.lower subscapular nerve(C5, 6) • 3.Thoracodorsal nerve(C6, 7, 8) • 4.Axillary nerve(C5, 6) • 5.Radial nerve(C5, 6, 7, 8; T1)
Relations • Roots and trunks lie in the neck-Supraclavicular part • Cords and branches lie in the axilla-Infraclavicular part
1. Dorsal scapular nerve (C5) • Rhomboid minor, rhomboid major, levator scapulae muscles
2. Long thoracic nerve (C5, 6, 7) • Serratus anterior muscle
3. Suprascapular nerve (C5, 6) • Supraspinatus and infraspinatus muscles
4. Nerve to subclavius (C5, 6) • Subclavius
5. Lateral pectoral nerve (C5, 6, 7) • Pectoralis major muscle
6.Musculocutaneous nerve (C5, 6, 7) • Coracobrachialis, biceps brachii, brachialis muscles
7. Median nerve(C5, 6, 7, 8; T1) • All muscles in the anterior compartment of the forearm (except flexor carpiulnaris and medial half of flexor digitorumprofundus), three thenar muscles of the thumb and two lateral lumbrical muscles
8. Medial pectoral nerve (C8; T1) • Pectoralis major and minor muscles
9. Medial cutaneous nerve of arm(C8; T1) • Skin of medial side of arm
10. Medial cutaneous nerve of forearm (C8; T1) • Skin of medial side of forearm
11.Ulnar nerve (C8; T1) • All intrinsic muscles of the hand (except three thenar muscles and two lateral lumbricals); also flexor carpiulnaris and the medial half of flexor digitorumprofundus in the forearm
12. Upper subscapular nerve (C5, 6) • Subscapularis muscle
13. Lower subscapular nerve (C5, 6) • Subscapularis and teres major muscles
14. Thoracodorsal nerve (C6, 7, 8) • Latissimusdorsi muscle
15. Radial nerve (C5, 6, 7, 8; T1) • All muscles in the posterior compartments of arm and forearm
16. Axillary nerve (C5, 6) • Deltoid, teres minor
Erb-Duchenne’s Palsy • Injury to C5-6 at Erb’s point • Muscles paralysed – Deltoid, biceps, brachialis, barachioradialis • Posture – waiter’s tip deformity • Mechanism of injury : fall on shoulder or excessive pulling of head of new born during delivery
Klumpke’s palsy • Injury to C8-T1 • Muscles paralyzed – small muscles of hand • Deformity Claw hand • Mechanism : Sudden superior pull
Symptoms: Clawed hand due to loss of innervation of Intrinsic muscle of the hand
wrist-drop The characteristic clinical sign of radial nerve injury is wrist-drop.
Fracture of the Humeral Shaft A midhumeral fracture may injure the radial nerve in the radial groove in the humeral shaft. Fracture is not likely to paralyze the triceps because of the high origin of the nerves to two of its three heads.