Pectoral region Lecture 2
Muscle Action Each muscle has: Origin Beginning. Insertion End. Body (belly). Law: When a muscle performs its action, its insertion, moves towards its origin. Spring 2016 Dr. Maher Hadidi, University of Jordan 2
Pectoral Region Spring 2016 Dr. Maher Hadidi, University of Jordan 3
Pectoral Region Breast region. Contents: 1. Skin. 2. Superficial fascia. 3. Breast. 4. Deep fascia. 5. 3 Muscles: a. Pectoralis major. b. Pectoralis minor. c. Subclavius. Spring 2016 Dr. Maher Hadidi, University of Jordan 4
Pectoralis major Dr. Maher Hadidi Origin: Clavicle (M ½), Sternum and upper 6 ribs. Insertion: humerus, lateral lip of intertubercular groove. Nerve Supply: Medial & lateral pectoral nerves. Action: Adducts and medially rotate the arm. Spring 2016 Dr. Maher Hadidi, University of Jordan 5
Pectoralis Minor O: 3rd, 4th, 5th ribs. Ins: Coracoid process. NS: Medial pectoral N. Action: Depress scapula downward and forward. Spring 2016 Dr. Maher Hadidi, University of Jordan 6
Subclavius Dr. Maher Hadidi Origin: 1st rib. Ins: Clavicle inferior surface. NS: N. to Subclavius. Action: Protects the underlying structures. Spring 2016 Dr. Maher Hadidi, University of Jordan 7
Dr. Maher Hadidi
Clavipectoral fascia A sheet of CT that connects clavicle to the floor of the axilla. It enclose subclavius and pectoralis minor and seals the gap between them. Pierced by: Thoracoacromial A. Cephalic vein. Lateral pectoral N. Dr. Maher Hadidi
Muscles connecting UL to vertebral col. Spring 2016 Dr. Maher Hadidi, University of Jordan 10
Deltoid O: Clavicle, acromion and spine of scapula. Ins: Deltoid tuberosity. Action: Its fibers runs in 3 directions Ant. flex shoulder. Post. extend should. Middle Abduct arm 15-90 0. NS: Axillary N. Dr. Maher Hadidi Spring 2016 Dr. Maher Hadidi, University of Jordan 11
Trapezius O: Skull, spines of C1-T12 v. Ins: Its fibers runs in 3 directions Down Clavicle. Horizontal Acromion. Up Spine of scapula. Action: Upper F. Elevate arm. Middle F. adduct medial Lower F. pull downward Assist the serratus anterior muscle in abducting the arm 180 0 above the head. NS: Spinal accessory (IX) N. Dr. Maher Hadidi Spring 2016 Dr. Maher Hadidi, University of Jordan 12
Latissmus dorsi O: T7-T12, L1- L5, Sacrum & Iliac crest. Ins: Floor of biceptal groove Action: extends, adducts and medially rotate humerus like in canoeing. NS: Thoracodorsal N. Dr. Maher Hadidi Spring 2016 Dr. Maher Hadidi, University of Jordan 13
Scapular muscles Lecture 3 Spring 2016 Dr. Maher Hadidi, University of Jordan 15
Muscles connecting UL to scapula Spring 2016 Dr. Maher Hadidi, University of Jordan 16
Supraspinatus O: Supraspinous fossa. Ins: Greater tubercle of humerus. Action: Abducts arm 0-15 0. NS: Suprascapular N. Infraspinatus O: Infraspinous fossa. Ins: Greater tubercle. Action: Lateral rotation of arm. NS: Suprascapular N. S i T Dr. Maher Hadidi Spring 2016 Dr. Maher Hadidi, University of Jordan 17
Teres Minor (L. Rounded) O: Lat. border of Scapula. Ins: Greater tubercle. Action: Lateral rotation of arm. NS: Axillary n. Teres Major O: Lat. border of Scapula. Ins: Medial lip of i.t groove Action: Adduction & Medial rotation and of arm. NS: Lower subscapular n. Dr. Maher Hadidi Spring 2016 Dr. Maher Hadidi, University of Jordan 18
Subscapularis Origin: Subscapular fossa. Ins: Lesser tubercle. Action: Medial rotation of the arm. NS: Upper and lower subscapular Ns. Dr. Maher Hadidi Spring 2016 Dr. Maher Hadidi, University of Jordan 19
Serratus anterior Origin: upper 8 ribs. Ins: Medial border of scapula. Act: Protraction of scapula (pulls scapula forward over thoracic wall). It assists trapezius to elevate arm 180 0 above shoulder. NS: Long thoracic N. Spring 2016 Dr. Maher Hadidi, University of Jordan 20
Rotator cuff muscles of shoulder Form of 4 muscles: Supraspinatus Infraspinatus Teres minor Subscapularis Their tendons flatten at their insertion and blend with the capsule of the shoulder joint. They act as a handcuff that strengthen shoulder joint (superior, posterior & anterior). But NOT inferior? Dr. Maher Hadidi S i T Spring 2016 Dr. Maher Hadidi, University of Jordan 21
Spaces between scapular muscles Quadrangular space Borders: Sup. T. minor Inf. T. major Med. Triceps, long h. Lat. humerus Contents: Axillary N. Post. circ. hum. A,V. Triangular space Borders: Sup, T. minor Inf, T. major Lat. Triceps, long head Contents: Circumflex scapular A & V. Dr. Maher Hadidi Spring 2016 Dr. Maher Hadidi, University of Jordan 22