MT-ant-shoulder-arm Anatomy PDF

The Anterior Aspect of the Shoulder and Arm Prof Dr MTiryakioglu  Cutaneous innervation Ventral rr of 1-6 thoracic spinal nn (intercostal nn) Ant cutaneous branches Lat cutaneous branches  Supraclavicular n (ant aspect of shoulder) Sup lat cut n of...

The Anterior Aspect of the Shoulder and Arm Prof Dr MTiryakioglu  Cutaneous innervation Ventral rr of 1-6 thoracic spinal nn (intercostal nn) Ant cutaneous branches Lat cutaneous branches  Supraclavicular n (ant aspect of shoulder) Sup lat cut n of arm (axillary n) Intercostobrachial n Inf lat cut n of arm Med cut n of arm Med cut n of forearm Lat cut n of forearm (musculocutaneous n)  Ant aspect of shoulder Superficial fascia Continuous with that of neck, upper limb above & abdomen below Contains mammary gland  Deep fascia Covers pectoralis major Pectoral fascia Extends between pectoralis major’s fasciculi Attaches sternum medially, clavicle above, continuous inferolaterally with fascia of shoulder, axilla, and thorax  Pectoral fascia Thin over pectoralis major Thicker between pectoralis major & latissimus dorsi; it crosses the axilla while forming the floor of it Axillary fascia splits into 2 at the lat margin of the latissimus dorsi; two layers ensheathe the muscle & attach to the spines of thoracic vertebrae  Infraclavicular fossa Separates upper border of pectoralis major from deltoid m Contents: Cephalic v, deltoid branch of thoracoacromial a Lower border of pectoralis major forms ant axillary fold  Clavipectoral fascia Strong fibrous sheath, behind clavicular part of pectoralis major Fills gap between pectoralis minor & subclavius Covers axillary vessels, nn vSplits around subclavius, attached to clavicle both ant & post to groove for subclavius Clavipectoral fascia clavipectoral fascia pierced by the cephalic v, thoracoacromial av, lat pectoral n, and lymph vessels) Pectoralis major Thick, fan-shaped O: Clavicular part: Ant surface of sternal half of clavicle. Sternocostal part: Ant surface of manubrium and body of sternum, costal cartilages of 2nd- 6th/7th ribs. Abdominal part: Aponeurosis of obliquus ext abd m Clavicular fibres separated from sternal fibres by a slight cleft  M converges to a flat tendon I: Lat lip of intertubercular sulcus (humerus) N: Med & lat pectoral nn F: Add & med rotation of humerus Clavicular head: Helps to flex humerus Sternocostal head: (From flexed position of humerus at the shoulder joint) extends humerus Pectoralis minor Post to pectoralis major Thin, triangular O: Upper margins & outer surfaces of 3-5th ribs, near their cartilages Fibres ascend laterally, under cover of pectoralis major, converging in a flat tendon I: Coracoid process Pectoralis minor N: Med & lat pectoral nn F: Assists serratus ant in drawing scapula forward around chest wall F: With levator scapulae & rhomboids; rotates scapula, depressing point of shoulder F: Active in forced inspiration  Subclavius m Small, triangular m tucked between clavicle & 1st rib O: Junction of 1st rib & its costal cartilage Passes upwards & lat I: Groove on the inf. surface of middle 1/3rd of clavicle N: Subclavian n of brachial plexus F: Pulls point of shoulder down & forward and steady the clavicle during shoulder movements  Serratus anterior O: Outer surfaces of first 8 ribs Lower 3 slips interdigitate with upper 5 slips of external oblique abdominis m Passes anterior to scapula & inserts the med border of scapula N: Long thoracic n (descends on the external surface of muscle)  F: Protracts scapula & holds it against thoracic wall F: By fixing the scapula to thorax, it acts as an anchor for this bone & Long thoracic n injury permits other mm to use Med border of scapula it as a fixed bone for moves postero-laterally away from the thoracic producing movements of wall on the affected side the humerus when the person presses arms against the wall ; the symptom is known as F: Inferior fibres help to winged scapula raise glenoid cavity Arm cannot be (when the arm is raised abducted above 90° above head) (serratus ant unable to rotate glenoid cavity sup) Anterior aspect of arm Superficial fascia Cutaneous nn Superficial vessels Cephalic v; drains to axillary v Basilic v; forms axillary v at lower border of teres major Median cubital vv  Brachial fascia Deep fascia Continuous with fascia covering deltoid & pectoralis major Forms med & lat intermuscular septa on each side of the humerus forming the ant and post compartments of arm  Coracobrachialis m O: Apex of coracoid process (together with tendon of short head of biceps) I: Middle 1/3 of med surface of body of humerus N: Musculocutaneous n (pierces the muscle) F: Add & flex of arm  Biceps brachii m Large, fusiform m O: Short head: Apex of coracoid process Long head: Supraglenoid tubercle Tendon of long head crosses head of humerus within capsule of shoulder joint, descends in intertubercular groove I: Tuberosity of radius and bicipital aponeurosis N: Musculocutaneous n F: Flex & supination of forearm Long head helps to flex arm  Brachialis m Post to biceps brachii Main flexor of forearm O: Distal half of ant surface of humerus, intermuscular septum I: Coronoid process & tuberosity of ulna N: Musculocutaneous n Blood Vessels of Shoulder and Arm Blood vessels Subclavian a >axillary a >brachial a 1st rib (outer border) - teres major (inf border) Pectoralis minor divides 3 parts according to prox, post & distal to muscle  Superior thoracic a Thoraco-acromial a pierces Branches of the Axillary A clavipectoral fascia o Pectoral o Acromial o Clavicular o Deltoid Lat thoracic a Subscapular a, largest branch o Circumflex scapular a o Thoracodorsal a Ant circumflex humeral a Post circumflex humeral a (quadrangular space w axillary n)  Brachial a Runs between the tendon of teres major (inf border) & 1 cm distal to elbow joint (neck of radius) Terminal branches: Radial & ulnar aa Vv comitantes course with the aa, connected by transverse & oblique branches Branches of the Brachial A Deep brachial a (largest brc accompanies the radial n in the radial groove) Ant descending br Post descending br Nutrient humeral a Sup&Inf ulnar collateral aa  Superficial vv Cephalic v Located in superficial fascia, along anterolat surface of biceps brachialis Enters infraclavicular fossa (passes behind clavicular head of pectoralis major) Passes between deltoid & pectoralis major Pierces clavipectoral fascia Crosses axillary a Joins axillary v ( just below clavicular level )  Basilic v In superficial fascia on the medial side of inf part of arm Near junction of middle & inf thirds, v passes deep to brachial fascia Courses superiorly into axilla In axilla, becomes axillary v  Median cubital v Communication between basilic & cephalic vv Ant to bicipital aponeurosis Venipuncture Variations  Nn of the arm Median n Ulnar n Musculocutaneous n Radial n Axillary n T H A N K Y O U