Muscles Flashcards
Pectoralis Major
Nerve
Action
Lateral and Medial Pectoral Nerves; Clavicular Head: C5, C6; Sternocostal Head: C7, C8, T1
Adducts and medially rotates humerus, draws scapula anteriorly
Alone: clavicular head flexes humerus; sternocostal: extends it from the flexed position
Pectoralis Major
Origin
Insertion
Parts
O: Clavicular Head: Anterior Surface of Medial half of clavicle, Sternocostal Head: Anterior surface of sternum, superior 6 costal cartilages, aponeurosis of external oblique muscle
Inserts: Lateral lip of intertubercular sulcus of humerus
Pectoralis Minor
Origin
Insertion
O: 3rd-5th ribs near their costal cartilages
I: Medial Border and Superior Surface of coracoid process of scapula
Pectoralis Minor
Nerve
Action
Medial Pectoral Nerve (C8, T1)
Stabilizes scapula by drawing inferiorly and anteriorly against thoracic wall
Subclavius
Origin
Insertion
Junction of 1st rib and its costal cartilage
inferior surface of middle third of clavicle
Subclavius
Nerve
action
Subclavian Nerve (C5, C6)
Anchors and depresses clavicle
Serratus Anterior
Origin
Insertion
External Surace of lateral parts of 1-8 ribs
Anterior surface of medial border of scapula
Serratus Anterior
Nerve
Action
Long Thoracic Nerve (C5, C6, C7)
Protracts scapula and holds against thoracic wall; rotates scapula
Trapezius
Origin
Insertion
medial third of superior nuchal line, EOP, nuchal ligament, spinous process C7-T12
Lateral third of clavicle, acromion and spine of scapula
Trapezius
Nerve
action
Spinal Accessory (CN XI), C3 C4
Elevation, depression and retraction
Latissimus Dorsi
Origin
Insertion
spinous process inferior 6 thoracic vertebrae, thoracolumbar fascia, illiac crest, inferior 3 or 4 ribs
floor of Intertubercular sulcus of humerus
Latissmus Doris
Nerve
action
Thoracodorsal Nerve (C6, C7, C8= Keep the lats great)
extends, adducts, medially rotates
Levator Scapulae
Origin
Insertion
Posterior tubercle of transverse process of C1-C4
medial border of scapula superior to the root of the spine
Levator Scapulae
Nerve
Action
Dorsal Scapular (C5) and Cervical (C3, C4)
elevates scapula, tilts glenoid cavity inferiorly
Rhomboid Minor
Origin
Insertion
Nuchal ligament, spinous process C7 T1 vertebrae
root of the spine of the scapula
Rhomboid Minor
Nerve
action
Dorsal Scapular (C4, C5)
retract scapula and rotate it to depress glenoid cavity, fix scapula to thoracic wall
Rhomboid Major
Origin
Insertion
Spinous process T2- T5
Inferior to the root of the spine of the scapula
Rhomboid Major
Nerve
Action
Dorsal Scapular (C4, C5)
retract scapula and rotate it to depress glenoid caivty fix scapula to thoracic wall
Deltoid
Origin
insertion
lateral third of clavicle, acromion and spine of scapula
deltoid tuberosity of humerus
Deltoid
nerve
action
Axillary nerve (C5, C6)
Clavicular: flex, medial rotation
Aromion: abducts
Spinal: extends laterally rotates
Supraspinatus
origin
insertion
Suprspinous Fossa of Scapula
Superior Facet of Greater Tubercle of Humerus
Supraspinatus
nerve
action
Suprascapular Nerve (C4,C5, C6)
initiates and assists deltoid in abduction acts with other rotator cuff muscles
Infraspinatus
origin
insertion
Infraspinous Fossa of Scapula
Middle Facet of Greater Tubercle of Humerus
Infraspinatus
nerve
action
Suprascapular (C4, C5, C6)
laterally rotates arm, help hold humeral head in glenoid cavity of scapula
Teres Minior
origin
insertion
Middle Part of Lateral Border of Scapula
Inferior Facet of Greater Tubercle of Humerus
Teres Minor
Nerve
Action
Axillary Nerve (C5, C6)
laterally rotates arm, help hold humeral head in glenoid cavity of scapula
Teres Major
Origin
Insertion
Posterior surface of inferior angle of scapula
Medial tip of Intertubercular Groove of humerus
Teres Major
nerve
action
Lower Subscapular Nerve (C5, C6)
Adducts and medially rotates arm
Subscapularis
Origin
Insertion
Subscapular Fossa (most anterior surface of scapula)
Lesser Tubercle of humerus
Subscapularis
nerve
action
Upper and Lower Subscapular Nerve (C5, C6, C7)
Medially roates and adducts arm, helps hold humeral head in glenoid cavity
Biceps Brachii
origin
insertion
parts
Short: tip of coracoid process of scapula
Long: Supraglenoid tubercle of scapula
Tuberosity of radius and fascia of forearm via bicipital aponeurosis
Biceps Brachii
Nerve
action
Musculocutaneous (C5, C6)
Supinates forearm, flexes forearm, flexes arm, resists dislocation of shoulder
Brachialis
origin
insertion
distal half of anterior surface of humerus
coronoid process and tuberosity of ulna
Brachialis
nerve
action
Musculocutaneous Nerve (C5, C6)
flexes forearm in all positions