Brachial Plexus PDF

BRACHIAL PLEXUS Dr saywan K.Asaad Brachial Plexus: ✔ At the root of the neck, the nerves form a complicated plexus called the brachial plexus. ✔ The brachial plexus is formed in the neck by the union of the anterior rami of the fifth, sixth, seventh, and eighth cervical and the first thoracic sp...

BRACHIAL PLEXUS Dr saywan K.Asaad Brachial Plexus: ✔ At the root of the neck, the nerves form a complicated plexus called the brachial plexus. ✔ The brachial plexus is formed in the neck by the union of the anterior rami of the fifth, sixth, seventh, and eighth cervical and the first thoracic spinal nerves. ✔ The plexus can be divided into roots, trunks, divisions, and cords ✔ The roots of C5 and 6 unite to form the upper (superior) trunk ✔ the root of C7 continues as the middle trunk, and the roots of C8 and T1 unite to form the lower (inferior) trunk ✔ Each trunk then divides into anterior and posterior divisions. ✔ 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 ✔ the posterior divisions of all three trunks join to form the posterior cord. ✔ The roots, trunks, and divisions of the brachial plexus lie in the neck. ✔ The cords lie in the axilla, arranged around the axillary artery. Cords of the Brachial Plexus: ✔ All three cords of the brachial plexus lie lateral to the first part of the axillary artery. ✔ The medial cord lies on the medial side of the second part of the artery. ✔ The posterior cord lies behind the second part of the artery, and the lateral cord lies on the lateral side of the second part of the artery. ✔ Most branches of the cords then continue this relationship to the axillary artery in its third part Branches of the Brachial Plexus: 1) Roots: – Dorsal scapular nerve. – Long thoracic nerve. 2) Upper trunk: – Nerve to subclavius. – Suprascapular nerve. 3) Lateral cord: – Lateral pectoral nerve. – Musculocutaneous nerve. – Lateral root of median nerve. 4) Medial cord: – Medial pectoral nerve. – Medial cutaneous nerve of arm and medial cutaneous nerve of forearm. – Ulnar nerve. – Medial root of median nerve. 5) Posterior cord: – – – – Upper and lower subscapular nerves. Thoracodorsal nerve. Axillary nerve. Radial nerve. Branches of the Brachial Plexus Found in the Axilla: ✔ The nerve to the Subclavius: supplies the subclavius muscle. ✔ It is important clinically because it may give a contribution (C5) to the phrenic nerve; this branch, when present, is referred to as the accessory phrenic nerve. ✔ The long thoracic nerve: supplies the serratus anterior muscle. ✔ The lateral pectoral nerve supplies the pectoralis major. ✔ The musculocutaneous muscles of the arm nerve supplies ✔ The lateral root and medial root of the median nerve: join together to form the median nerve. The median nerve gives off no branches in the axilla. ✔ The medial pectoral nerve: supplies pectoralis minor & pectoralis major muscles ✔ The medial cutaneous nerve of the arm: is joined by the intercostobrachial nerve (branch of the second intercostal nerve). It supplies the skin on the medial side of the arm. ✔ The medial cutaneous nerve of the forearm: supplies the medial side of forearm ✔ ulnar nerve: gives off no branches in the axilla. ✔ upper and lower subscapular nerves: supply the upper and lower parts of the subscapularis muscle. In addition, the lower subscapular nerve supplies the teres major muscle ✔ thoracodorsal nerve: supplies the latissimus dorsi ✔ The radial nerve is the largest branch of the brachial plexus. ✔ It gives off branches to the long and medial heads of the triceps muscle and the posterior cutaneous nerve of the arm THANK YOU