Section 1: Upper Extremities Flashcards
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Cards 94-103
Muscles that control the GH joint
- Deltoid
- Pectoralis Major
- Biceps brachii
- Latissimus dorsi
- Teres Major
- Triceps brachii
- Rotator Cuff Muscles
a. Supraspinatus
b. Infraspinatus
c. teres minor
d. subscapularis
Deltoid
Or: Lateral third of clavicle, acromion, and spine of scapula
Ins: Deltoid tuberosity of humerus
Inv: Axillary Nerve
BS: thoracoacromial artery, posterior humeral circumflex artery
Action: Clavicular (anterior) part: Flexes and medially rotates arm
Acromial (middle) part: Abducts arm
Spinal (posterior) part: extends and laterally rotates arm
Pectoralis Major
Or: Clavicular head: anterior surface of medial half of clavicle
Sternocostal head: anterior sufrace of sternum, superior six costal cartilages, aponeurosis of external oblique muscle
Ins: Lateral lip of intertubercular sulcus of humerus
Inv: Lateral and medial pectoral nerve (C5, C6), sternocostal head (C7, C8*, T1)
BS: Pectoral branch of the thoracoacromial trunk
Action: Adducts and medially rotates humerus; draws scapula anteriorly and inferiorly.
Acting alone, clavicular head flexes humerus and sternocostal head extends it from the flexed position
Short head of the Biceps brachii
Or: tip of coracoid process of scapula
Ins: Tuberosity of radius and fascia of forearm via bicipital aponeurosis
Inv: Musculocutaneous nerve (C5, C6*, C7)
BS: Brachial artery
Action: Supinates forearm and when it is supine, flexes forearm; short head resists dislocation of shoulder
Latissimus dorsi
Or: Spinous processes of inferior 6 thoracic vertebrae, thoracolumbar fascia, iliac crest, and inferior 3 or 4 ribs
Ins: floor of intertubercular sulcus of humerus
Inv: thoracodorsal nerve (C6, C7, C8)
BS: thoracodorsal artery
Action: Extends, adducts, and medially rotates humerus; raises body toward arms during climbing
Teres Major
Or: Posterior surface of inferior angle of scapula
Ins: Medial lip of intertubercular sulcus of humerus
Inv: Lower subscapular nerve (C5, C6*)
BS: Subscapular artery and circumflex scapular artery
Action: Adducts and medially rotates arm
Triceps brachii Long head
Or: infraglenoid tubercle of scapula
Ins: Proximal end of olecranon of ulna and facia of forearm
Inv: Radial nerve (C6, C7, C8)
BS: Deep brachial artery
Action: Chief extensor of forearm; Long head resists dislocation of humerus especially important during adduction
Supraspinatus
Or: Supraspinous fossa of scapula
Ins: Superior facet of greater tubercle of humerus
Inv: Suprascapular nerve (C4, C5*, C6)
BS: Suprascapular artery
Action: Initiates and assists deltoid in abduction of arm and acts with rotator cuff muscles
Infraspinatus
Or: Infraspinous fossa of scapula
Ins: Middle facet of greater tubercle of humerus
Inv: Suprascapular nerve (C5*, C6)
BS: Suprascapular Artery and circumflex artery
Action: Laterally rotates arm; and acts with Rotator cuff muscles
Teres Minor
Or: Middle part of lateral border of scapula
Ins: Inferior facet of greater tubercle of humerus
Inv: Axillary nerve (C5*, C6)
BS: Posterior humeral circumflex artery and circumflex scapular artery
Action: Adducts and medially rotates arm
Subscapularis
Or: Subscapular fossa (most of anterior surface of scapula)
Ins: Lesser tubercle of humerus
Inv: Upper and lower subscapular nerves (C5, C6*, C7)
BS: Subscapular artery
Action: Medially rotates arm, as part of the rotator cuff muscles, helps hold head of humerus in glenoid cavity
Pectoralis Minor
Or: 3rd-5th rib near their costal cartilages
Ins: Medial border and superior surface of coracoid process of scapula
Inv: Medial pectoral nerve (C8, T1)
Action: Stabilizes scapula by drawing it inferiorly and anteriorly against thoracic wall
Long head of the biceps brachii
Or: supraglenoid tubercle of scapula
Ins: Tuberosity of radius and fascia of forearm via bicipital aponeurosis
Inv: Musculocutaneous nerve (C5, C6*, C7)
BS: Brachial artery
Action: Supinates forearm and when it is supine, flexes forearm; short head resists dislocation of shoulder
Triceps brachii Lateral Head
Or: Posterior surface of humerus, superior to radial groove
Ins: Proximal end of olecranon of ulna and facia of forearm
Inv: Radial nerve (C6, C7, C8)
BS: Deep brachial artery
Action: Chief extensor of forearm; Long head resists dislocation of humerus especially important during adduction