Lab Activity 11: Group II Muscles Martini Chapter 11 Portland Community College BI 231
Origin and Insertion Origin: The place where the fixed end attaches to a bone, cartilage, or connective tissue. Insertion: The site where the movable end attaches to another structure. 2
Deltoid Origin: Anterior surface, lateral clavicle, acromion process and spine of scapula Insertion: Deltoid tubercle of humerus Action: Abducts humerus; aids in flexion, extension, and internal and external rotation 3
Supraspinatus Origin: Supraspinous fossa Insertion: Greater tubercle of humerus Action: Abducts humerus 4
Infraspinatus Origin: Infraspinous fossa Insertion: Greater tubercle of humerus Action: Rotates humerus laterally 5
Teres Minor Origin: Axillary border of scapula Insertion: Greater tubercle of humerus Action: Rotates humerus laterally 6
Teres Major Origin: Axillary border at inferior angle of scapula Insertion: Intertubular groove of humerus Action: Extends, adduction and medial rotates humerus. 7
Subscapularis Origin: Subscapular fossa Insertion: Lesser tubercle of humerus Action: Rotates humerus medially 8
Biceps Brachii Origin: Long head, supraglenoid tubercle; Short head, coracoid process scapula Insertion: Radial tuberosity of the radius Action: Flexes radius and humerus, and supinates forearm Short Head Long Head 9
Coracobrachialis Origin: Coracoid process of scapula Insertion: Middle third of humerus Action: Flexes and adducts humerus 10
Triceps Brachii Long Head Lateral Head Origin: Long head, infraglenoid tubercle; Lateral head, proximal portion of posterior humerus; Medial head, distal half of posterior humerus Insertion: Olecranon process of ulna Action: Extends humerus and ulna 11
Brachialis Origin: Anterior distal two-thirds of humerus Insertion: Coronoid process of ulna Action: Flexes ulna 12
Anconeus Origin: Lateral epicondyle of humerus Insertion: Olecranon process, posterior surface of ulna Action: Weak extensor of ulna, stabilizes elbow joint in extension 13
Abductor Pollicis Brevis Origin: Scaphoid and trapezium Insertion: Proximal phalanx of thumb Action: Abducts thumb and aids in flexion Palm 14
Flexor Pollicis Brevis Origin: Trapezium Insertion: Proximal phalanx of thumb Action: Flexes thumb 15 Palm
Flexor Digiti Minimi Origin: Hook of hamate Insertion: Proximal phalanx of fifth digit Action: Flexes fifth digit 16 Palm
Abductor Digiti Minimi Origin: Pisiform and tendon of flexor carpi ulnaris Insertion: Proximal phalanx of fifth digit Action: Abducts fifth digit 17 Palm
Pronator Teres Origin: Medial epicondyle of humerus and coronoid process of ulna Insertion: Middle portion of radius Action: Pronates and flexes forearm Anterior, Superficial Layer 18
Flexor Carpi Radialis Origin: Medial epicondyle of humerus Insertion: Base of second metacarpal Action: Flexes wrist and elbow and abducts wrist Anterior, Superficial Layer 19
Palmaris Longus Origin: Medial epicondyle of the humerus Insertion: Palmar aponeurosis Action: Weak flexion of wrist, tenses skin of palm Anterior, Superficial Layer 20
Flexor Carpi Ulnaris Origin: Medial epicondyle of humerus, olecranon process, & posterior ulna Insertion: Pisiform, hamate, and fifth metacarpal Action: Flexes and adducts wrist Anterior, Superficial Layer 21
Flexor Digitorum Superficialis Origin: Medial epicondyle of humerus and coronoid process of ulna Insertion: Middle phalanges of fingers Action: Flexes fingers and wrist 22 Anterior, Middle Layer
Flexor Digitorum Profundus Origin: Anterior and medial surfaces of ulna and interosseous membrane Insertion: Distal phalanges of fingers Action: Flexes fingers and wrist 23 Anterior, Deepest Layer
Flexor Pollicis Longus Origin: Middle half of radius, interosseous membrane, coronoid process of ulna Insertion: Distal phalanx of thumb Action: Flexes thumb and wrist 24 Anterior, Deepest Layer
Brachioradialis Origin: Lateral supracondylar ridge Insertion: Styloid process of radius Action: Flexes forearm 25 Posterior, Superficial Layer
Extensor Carpi Radialis Longus Origin: Lateral supracondylar ridge of humerus Insertion: Second metacarpal Action: Extends and abducts hand 26 Posterior, Superficial Layer
Extensor Carpi Radialis Brevis Origin: Lateral epicondyle of humerus Insertion: Third metacarpal Action: Extends and abducts hand 27 Posterior, Superficial Layer
Extensor Digitorum Origin: Lateral epicondyle of humerus Insertion: Into distal phalanx by 4 tendons Action: Extends fingers and hand 28 Posterior, Superficial Layer
Extensor Carpi Ulnaris Origin: Lateral epicondyle of humerus and posterior border of ulna Insertion: Fifth metacarpal Action: Extends and adducts hand 29 Posterior, Superficial Layer
Extensor Digiti Minimi Origin: Lateral epicondyle of humerus Insertion: Extensor expansion of little finger Action: Extends 5 th digit and hand 30 Posterior, Middle Layer
Supinator Origin: Lateral epicondyle of humerus, supinator crest of ulna Insertion: Lateral surface and posterior border of radius Action: Supinates forearm 31 Posterior, Deepest Layer
Abductor Pollicis Longus Origin: Posterior surface of ulna and radius, and interosseous membrane Insertion: First metacarpal Action: Abducts thumb and hand 32 Posterior, Deepest Layer
Extensor Pollicis Brevis Origin: Middle third of radius and interosseous membrane Insertion: Base of proximal phalanx of thumb Action: Extends thumb 33 Posterior, Deepest Layer
Extensor Pollicis Longus Origin: Middle third of ulna and interosseous membrane Insertion: Base of distal phalanx of thumb Action: Extends thumb 34 Posterior, Deepest Layer
The End 35