Quadrangular space Structures passing through: Axillary nerve vein Posterior circumflex humeral artery & vein Triangular space Structures passing through: Circumflex scapular artery & vein Triangular interval Structures passing through Radial nerve profunda brachii artery associated veins Radial nerve & profunda brachii artery (deep artery of arm) & associated veins IV.COMMITTEE I. LAB QUIZ NOTES

6 branches of axillary artery 1 branch (1st part) superior thoracic artery 2 branches (2nd part) thoraco-acromial artery & lateral thoracic artery 3 branches (3nd part) subscapular artery, anterior circumflex humeral artery, posterior circumflex humeral artery IV.COMMITTEE I. LAB QUIZ NOTES

Branches of the lateral cord 1.Lateral pectoral nerve 2.Musculocutaneous nerve 3.Lateral root of median nerve Branches of the medial cord 1.Medial pectoral nerve 2.Medial cutaneous nerve of arm 3.Medial cutaneous nerve of forearm(medial antebrachial cutaneous nerve) 4.Ulnar nerve 5.Median nerve Branches of the posterior cord 1.Superior subscapular nerve 2.Thoracodorsal nerve 3.Inferior subscapular nerve 4.Axillary nerve 5.Radial nerve IV.COMMITTEE I. LAB QUIZ NOTES

Table 1. Extrinsic back muscles [Superficial (appendicular) group & intermediate (respiratory) group of back muscles] IV.COMMITTEE I. LAB QUIZ NOTES

MuscleProximal Attachment (Origin) Distal Attachment (Insertion) InnervationFunction Biceps brachiiShort head: tip of coracoid process of scapula Long head: supraglenoid tubercle of scapula Tuberosity of radius and fascia of forearm via bicipital aponeurosis Musculocutaneous nerve (C5, C6, C7) Supinates forearm and, when it is supine. flexes forearm; short head resists dislocation of shoulder CoracobrachialisTip of coracoid process of scapula Middle third of medial surface of humerus Musculocutaneous nerve (C5, C6, C7) Helps flex and adduct arm; resists dislocation of shoulder BrachialisDistal half of anterior surface of humerus Coronoid process and tuberosity ulna Musculocutaneous nerve (C5, C6, C7) and small contribution by the radial nerve at the lateral part Flexes forearm in all positions Triceps brachiiLong head: infraglenoid tubercle of scapula Lateral head: posterior surface of humerus, superior to radial groove Medial head: posterior surface of humerus, inferior to radial groove Proximal end of olecranon of ulna and fascia of forearm Radial nerve (C6, C7, C8) Chief extensor of forearm; long head resists dislocation of humerus; especially important during adduction Table 2. Muscles of the arm IV.COMMITTEE I. LAB QUIZ NOTES

MuscleOriginInsertionNerveFunction DeltoidLateral third of clavicle; acromion and spine of scapula Deltoid tuberosity of humerus Axillary nerveClavicular (anterior) part: flexes and medially rotates arm Acromial (middle) part: abducts arm Spinal (posterior) part: extends and laterally rotates arm SupraspinatusSupraspinous fossa of scapula Superior facet of greater tubercle of humerus Suprascapular nerve Initiates and assists deltoid in abduction of arm and acts with rotator cuff muscles InfraspinatusInfraspinous fossa of scapula Middle facet of greater tubercle of humerus Suprascapular nerve Laterally rotates arm; and acts with rotator cuff muscles Teres minorMiddle part of lateral border of scapula Inferior facet of greater tubercle of humerus Axillary nerveLaterally rotates arm; and acts with rotator cuff muscles Teres majorPosterior surface of inferior angle of scapula Medial lip of intertubercular sulcus of humerus Inferior subscapular nerve Adducts and medially rotates arm SubscapularisSubscapular fossa (most of anterior surface of scapula) Lesser tubercle of humerus Sup. & Inf. subscapular nerves Medially rotates arm; as part of rotator cuff, helps hold head of humerus in glenoid cavity Table 3. Scapulohumeral (Intrinsic) shoulder muscles Collectively, the supraspinatus, infraspinatus, teres minor, and subscapularis muscles are referred to as the rotator cuff, or SITS, muscles. Their primary function during all movements of the glenohumeral (shoulder) joint is to hold the humeral head in the glenoid cavity of the scapula. IV.COMMITTEE I. LAB QUIZ NOTES