Presentation on theme: "DEPARTMENT OF ANATOMY UPPER LIMB SHOULDER. The shoulder is the region of upper limb attachment to the trunk and neck."— Presentation transcript:
DEPARTMENT OF ANATOMY UPPER LIMB SHOULDER
The shoulder is the region of upper limb attachment to the trunk and neck.
A large muscle that arises from two heads flexes and medially rotates the arm. It is innervated by nerves arising from different cords of the brachial plexus. This is the: A.Latissimus dorsi B.Trapezius C.Deltoid D.Subscapularis E.Pectoralis major
Clavicle and scapula, which form the pectoral girdle (shoulder girdle) The proximal end of the humerus.
1. PECTORALIS MAJOR 2. PECOTORALIS MINOR 3. SUBCLAVIUS 4. SERRATUS ANTERIOR
Origin: Clavicle, sternum, and upper six costal cartilages Insertion : Lateral lip of bicipital groove of humerus N. supply : Medial and lateral pectoral nerves Action : Adducts arm and rotates it medially; clavicular fibers also flex arm
Origin: Third, fourth, and fifth ribs Insertion : Coracoid process of scapula N. supply : Medial pectoral nerve Action: Stabilizes scapula by drawing it inferiorly
Origin: First costal cartilage Insertion : Clavicle N. supply : Nerve to subclavius Action: Depresses the clavicle
Origin: Upper eight ribs Insertion :Anterior surface of medial border of scapula N. supply : Long thoracic nerve Action: Protracts scapula and rotates scapula
When the serratus anterior is paralyzed owing to injury to the long thoracic nerve, the medial border of the scapula moves laterally and posteriorly away from the thoracic wall, giving the scapula the appearance of a wing. Due to loss of Innervation-long thoracic nerve
All the following muscles have a relationship to the scapula. If paralyzed, which muscle results in winging of the scapula with inability to elevate the arm above the horizontal? A.Serratus anterior B. Latissimus dorsi C.Levator scapulae D. Rhomboid major E.Deltoid
The posterior axioappendicular muscles attach the superior appendicular skeleton (of the upper limb) to the axial skeleton (in the trunk). 1.Trapezius 2.Latissimus dorsi 3. Rhomboid major and minor 4. Levator scapulae
Origin: Occipital bone, ligamentum nuchae, spine of seventh cervical vertebra, spines of all thoracic vertebrae Insertion : Upper fibers into lateral third of clavicle; middle and lower fibers into acromion and spine of scapula N. supply : Spinal part of accessory nerve (motor) Action: Upper fibers elevate the scapula; middle fibers pull scapula medially; lower fibers pull medial border of scapula downward
The primary clinical manifestation of accessory nerve palsy is a marked ipsilateral weakness when the shoulders are elevated (shrugged) against resistance.
Origin: Iliac crest, lumbar fascia, spines of lower six thoracic vertebrae, lower three or four ribs, and inferior angle of scapula Insertion: Floor of bicipital groove of humerus N. supply :Thoracodorsal nerve
Action: Extends, adducts, and medially rotates the arm
Surgery in the inferior part of the axilla puts the thoracodorsal nerve supplying the latissimus dorsi at risk of injury. With paralysis of the latissimus dorsi, the person is unable to raise the trunk with the upper limbs, as occurs during climbing.
Origin: Transverse processes of first four cervical vertebrae Insertion: Medial border of scapula N. supply :dorsal scapular nerve Action:Elevates scapula
An 34 year old man, bleeding from a stab wound in the neck, is brought to the emergency department. After the bleeding has been controlled, further examination indicates that her left shoulder is lower than the right shoulder. Which of the following nerve is most likely injured? A Long thoracic B Dorsal scapular C Axillary D Suprascapular E Spinal accessory
A 22 year old woman sustains a traumatic injury to the axilla that severely damages the thoracodorsal nerve. Which of the following movements is most likely affected in this patient? a Adduction B. Flexion C Lateral rotation D Protraction E Supination
Scapulohumeral muscles: The six scapulohumeral muscles are relatively short muscles that pass from the scapula to the humerus and act on the glenohumeral joint. 1.Deltoid 2.Teres major 3.Teres minor 4.Supraspinatus 5.Infraspinatus 6.Subscapularis
Origin: Lateral third of clavicle, acromion, spine of scapula Insertion: Middle of lateral surface of shaft of humerus N. supply : Axillary nerve
Action: Anterior part: flexes and medially rotates arm Middle part: abducts arm Posterior part: extends and laterally rotates arm
The examiner resists the patient's abduction of the limb by the deltoid. If the deltoid is acting normally, contraction of the middle part of the muscle can be palpated.
The deltoid is a common site for the intramuscular injection of drugs. The axillary nerve runs transversely under cover of the deltoid at the level of the surgical neck of the humerus. The deltoid atrophies when the axillary nerve (C5 and C6) is severely damaged.
Origin: Lower third of lateral border of scapula Insertion:Medial lip of bicipital groove of humerus N. supply :Lower subscapular nerve Action:Adducts and medially rotates arm
Four of the scapulohumeral muscles supraspinatus, infraspinatus, teres minor, and subscapularis (referred to as the SITS muscles) are called rotator cuff muscles because they form a musculotendinous rotator cuff around the glenohumeral joint.
Origin: Supraspinous fossa of scapula Insertion: Superior facet of greater tubercle of humerus N. supply : Suprascapular nerve Action: Initiates and assists deltoid in abduction of arm and acts with rotator cuff muscles.
Origin: Infraspinous fossa of scapula Insertion: Middle facet of greater tubercle of humerus N. supply : Suprascapular nerve Action: Laterally rotates arm and stabilizes shoulder joint
Origin: Middle part of lateral border of scapula Insertion: Inferior facet of greater tubercle of humerus N. supply :Axillary nerve Action:Laterally rotates arm and stabilizes shoulder joint
Origin: Subscapular fossa (most of anterior surface of scapula) Insertion: Lesser tubercle of humerus N. supply : Upper and lower subscapular nerves Action: Medially rotates and adduct arm
Trauma may tear or rupture one or more of the tendons of the SITS muscles; that of the supraspinatus is most commonly involved.
Which of the following muscles listed below is the rotator cuff muscle involved in medial rotation of the humerus? A Supraspinatus B Subscapularis C Infraspinatus D Teres minor E Teres major
A 31 year old man is unable to raise his right arm above his head 3 weeks after dislocating his shoulder in a foot ball game. Examination shows absence of rounded contour of the shoulder. Which of the following nerves was most likely injured? A. Musculocutaneous B. Median C. Axillary D. Ulnar E.Radial
Superior border: Teres Minor Inferior border: Teres Major Lateral border: Surgical neck of the humerus Medial border: Long Head of Triceps