Presentation on theme: "B C A B DISSECTION OF THE PECTORAL REGION AND AXILLA"— Presentation transcript:
1B C A B DISSECTION OF THE PECTORAL REGION AND AXILLA Make certain you have reviewedthe anatomy of the brachial plexusthe branches of the axillary arterythe anatomy of the superficial veins in this region!!!BCAB
7PECTORAL SKIN INCISIONS Using the following slide as a reference, make the following skin incisions with the cadaver in the supine position.From the jugular notch A along the clavicle and across the acromion B to a point about 10 cm distal to the acromion.From A to the xiphisternal junction C.From C laterally to the table.At about mid-arm, make a complete circular incision.At the level of the wrist make another circular incision.Join these two circular incisions with a longitudinal one on the lateral aspect of the upper limb, that extends to the cut that is distal to the acromion.. Reflect the skin of the arm and forearm and remove it completely. DO NOT damage the superficial veins and cutaneous nerves in the superficial fascia.
9Clean the anterior surface of the pectoralis major muscle and define its borders. Recall that the pectoralis major muscle has two heads: a clavicular and sternocostal head. The fibers of the two heads converge and insert into the lateral lip of the bicipital groove of the humerus.
10Identify the cephalic vein piercing the fascia of the deltopectoral triangle.
11When beginning dissection in this region, recognize and SAVE the thoracoacormial trunk or artery as it exits the axillary artery
12Cut the sternocostal head of pectoralis major muscle near its attachment to the sternum and the costal cartilage of the 6th rib and reflect it laterally.
13Lateral pectoral nerve Pectoralis minor m.Medial pectoral nerveThe medial and lateral pectoral nerves are named for the cords of the brachial plexus from which they arise and not for their relationship to pectoralis minor m..You should note some branches of the thracoacromial artery accompanying these nerves.Serratus anterior m.
15Identify the borders of the pectoralis minor m Identify the borders of the pectoralis minor m. Cut it near its attachments to the ribs and reflect the muscle superiorly towards its attachment to the coracoid process.
16As you reflect the pectoralis minor m As you reflect the pectoralis minor m., you should be able to better view the medial and lateral poctoral nn. And the accompanying vessels, which are branches of the thoracoacromial artery.Remember that the thoracoacromial a. arises from the second part of the axillary a., which is the portion of the vessel that lies deep to the pectoralis minor m.Thorcoacromial a.
17This is a good time to also identify and save the lateral thoracic a This is a good time to also identify and save the lateral thoracic a., which also comes off the second part of the axillary a..It can be found along the lateral border of the pectoralis minor m. accompanied by the long thoracic n. which innervates the serratus anterior m..Subclavius m.Lateral thoracic a.Long thoracic n.
18Brachial Plexus C5 C6 C7 C8 T1 Long thoracic nerve SUPERIOR MIDDLE ANT.MIDDLEPOST.T1INFERIORLATERALPOSTERIORMUSCULOCUT.AXILLARYMEDIALRADIALMEDIAN.ULNAR
19The axilla is described anatomically as having four walls. Anterior – clavicle and pectoral mm.Lateral – humerus.Medial – ribs and intercostal mm..Posterior – scapula and subscapularis m.
20The axilla is described anatomically as having four walls. Anterior – clavicle and pectoral mm.Lateral – humerus.Medial – ribs and intercostal mm..Posterior – scapula and subscapularis m.
21Make certain that the arm is in an abducted position to facilitate the cleaning of the nerves and vessels.Be careful to NOT cut the nerves and blood vessels contained in the axilla as the superficial fascia is removed.
30Medial cutaneous nerve of the arm or medial brachial cutaneous nerve You will notice two nerves running adjacent to the ulnar nerve that may arise separately from the medial cord or from a common trunk – the medial brachial cutaneous and medial antebrachial cutaneous nerves.These nerves provide cutaneous innervation to the medial aspect of the arm and forearm.Medial cutaneous nerve of the arm or medial brachial cutaneous nerveMedial cutaneous nerve of the forearm or medial antebrachial cutaneous nerve
32Intercostalbrachial nerve You may also see the intercostobrachial nerve which actually arises from the second or third intercostal nerves.It will often communicate with the medial brachial cutaneous nerve. The intercostobrachial nerve primarily supplies the skin on the floor of the axilla and some of the adjacent regions of the arm.Intercostalbrachial nerve
33Lateral pectoral nerve arising from the lateral cord Medial pectoral nerve arising from the medial cordYou should be able to trace the medial and lateral pectoral nerves to their origins from the medial and lateral cords of the brachial plexus.
34Now, let’s take another look at the axillary artery which begins at the lateral border of the first rib as the continuation of the subclavian artery.It is described as being made up of three parts relative to the pectoralis minor muscle.
35The first part of the axillary artery lies between the lateral border of the first rib and the medial border of pectoralis minor muscle.
36reflected pectoralis minor muscle The second part of the axillary artery lies posterior to the pectoralis minor muscle.
37The third part of the axillary artery lies between the lateral border of the pectoralis minor muscle and inferior border of teres major muscle.As the axillary artery passes distal to the teres major muscle, its name changes to the brachial artery.
38BRANCHES OF THE AXILLARY ARTERY First Part (located between lateral border of first rib and superior border of pectoralis minor)1. superior thoracic arterySecond Part (deep to the pectoralis minor muscle)1. thoracoacromial trunk or artery2. lateral thoracic arteryThird Part ( from inferior border of the pectoralis minor muscle to the inferior border of the teres major muscle)1. subscapular artery2. anterior circumflex humeral artery3. posterior circumflex humeral artery
40Branch of the First Part of the Axillary Artery Superior thoracic a.
41Branches of the Second Part of the Axillary Artery Thoracoacromial trunk which gives rise to four branches: (1) deltoid, (2) acromial, (3) clavicular, and (4) pectoral
42Branches of the Second Part of the Axillary Artery Thoracoacromial trunk which gives rise to four branches: (1) deltoid, (2) acromial, (3) clavicular, and (4) pectoral
43Branches of the Second Part of the Axillary Artery Lateral thoracic artery which exits the axillary artery AFTER the thoracoacromial trunk and then follows the lateral border of the pectoralis minor muscle.
44Branches of the Third Part of the Axillary Artery
45Branches of the Third Part of the Axillary Artery Subscapular artery which is the largest of the branches of the axillary artery.
46Branches of the Third Part of the Axillary Artery Subscapular arteryThoracodorsal artery is a branch of the subscapular artery.Circumflex scapular artery is a branch of the subscapular artery.
47Branches of the Third Part of the Axillary Artery Anterior circumflex humeral artery which usually travels deep to the coracobrachialis muscle and the short head of the biceps brachii muscle before anastomosing with the posterior humeral circumflex artery.
48Branches of the Third Part of the Axillary Artery Posterior circumflex humeral artery which is usually the larger of the two circumflex arteries.
49Make certain that you have cleaned the posterior cord of the brachial plexus.
53Lower subscapular n. going to subscapularis and teres major muscles You may see the three smaller branches of the posterior cord of the brachial plexus lying anterior to the subscapularis muscle (1) upper subscapular n., (2) lower subscapular n., and (3) the thoracodorsal n..Lower subscapular n. going to subscapularis and teres major muscles
54Thoracodorsal n.. going to the latissimus dorsi muscle