Lab Activity 11: Group II
Muscles
Martini Chapter 11
Portland Community CollegeBI 231
2
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.
MUSCLES OF THE SHOULDER AND ARM
4
• 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
Deltoid
5
• Origin: Supraspinous fossa
• Insertion: Greater tubercle of humerus
• Action: Abducts humerus
Supraspinatus
6
• Origin: Infraspinous fossa
• Insertion: Greater tubercle of humerus
• Action: Rotates humerus laterally
Infraspinatus
7
• Origin: Axillary border of scapula
• Insertion: Greater tubercle of humerus
• Action: Rotates humerus laterally
Teres Minor
8
• Origin: Axillary border at inferior angle of scapula
• Insertion: Intertubular groove of humerus
• Action: Extends, adduction and medial rotates humerus.
Teres Major
9
• Origin: Subscapular fossa
• Insertion: Lesser tubercle of humerus
• Action: Rotates humerus medially
Subscapularis
10
• Origin: Long head, supraglenoid tubercle;Short head, coracoid process scapula
• Insertion: Radial tuberosity of the radius
• Action: Flexes radius and humerus, and supinates forearm
Biceps BrachiiShort Head Long
Head
11
• Origin: Coracoid process of scapula
• Insertion: Middle third of humerus
• Action: Flexes and adducts humerus
Coracobrachialis
12
• 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
Triceps Brachii Long Head
Lateral Head
13
• Origin: Anterior distal two-thirds of humerus
• Insertion: Coronoid process of ulna
• Action: Flexes ulna
Brachialis
14
• Origin: Lateral epicondyle of humerus
• Insertion: Olecranon process, posterior surface of ulna
• Action: Weak extensor of ulna, stabilizes elbow joint in extension
Anconeus
MUSCLES OF THE PALM
16
• Origin: Scaphoid and trapezium
• Insertion: Proximal phalanx of thumb
• Action: Abducts thumb and aids in flexion
Palm
Abductor Pollicis Brevis
17
• Origin: Trapezium • Insertion: Proximal
phalanx of thumb • Action: Flexes thumb
PalmPalm
Flexor Pollicis Brevis
18
• Origin: Hook of hamate
• Insertion: Proximal phalanx of fifth digit
• Action: Flexes fifth digit
PalmPalm
Flexor Digiti Minimi
19
• Origin: Pisiform and tendon of flexor carpi ulnaris
• Insertion: Proximal phalanx of fifth digit
• Action: Abducts fifth digit
PalmPalm
Abductor Digiti Minimi
MUSCLES OF ANTERIOR FOREARM
21
• Origin: Medial epicondyle of humerus and coronoid process of ulna
• Insertion: Middle portion of radius
• Action: Pronates and flexes forearm
Pronator Teres
Anterior, Superficial Layer
22
• Origin: Medial epicondyle of humerus
• Insertion: Base of second metacarpal
• Action: Flexes wrist and elbow and abducts wrist
Flexor Carpi Radialis
Anterior, Superficial Layer
23
• Origin: Medial epicondyle of the humerus
• Insertion: Palmar aponeurosis
• Action: Weak flexion of wrist, tenses skin of palm
Palmaris Longus
Anterior, Superficial Layer
24
• Origin: Medial epicondyle of humerus, olecranon process, & posterior ulna
• Insertion: Pisiform, hamate, and fifth metacarpal
• Action: Flexes and adducts wrist
Flexor Carpi Ulnaris
Anterior, Superficial Layer
25
• Origin: Medial epicondyle of humerus and coronoid process of ulna
• Insertion: Middle phalanges of fingers
• Action: Flexes fingers and wrist
Flexor Digitorum Superficialis
Anterior, Middle Layer
26
• Origin: Anterior and medial surfaces of ulna and interosseous membrane
• Insertion: Distal phalanges of fingers
• Action: Flexes fingers and wrist
Flexor Digitorum Profundus
Anterior, Deepest Layer
27
• Origin: Middle half of radius, interosseous membrane, coronoid process of ulna
• Insertion: Distal phalanx of thumb
• Action: Flexes thumb and wrist
Flexor Pollicis Longus
Anterior, Deepest Layer
MUSCLES OF POSTEROLATERAL FOREARM
29
• Origin: Lateral supracondylar ridge
• Insertion: Styloid process of radius
• Action: Flexes forearm
Brachioradialis
Posterior, Superficial Layer
30
• Origin: Lateral supracondylar ridge of humerus
• Insertion: Second metacarpal
• Action: Extends and abducts hand
Extensor Carpi Radialis Longus
Posterior, Superficial Layer
31
• Origin: Lateral epicondyle of humerus
• Insertion: Third metacarpal
• Action: Extends and abducts hand
Extensor Carpi Radialis Brevis
Posterior, Superficial Layer
32
• Origin: Lateral epicondyle of humerus
• Insertion: Into distal phalanx by 4 tendons
• Action: Extends fingers and hand
Extensor Digitorum
Posterior, Superficial Layer
33
• Origin: Lateral epicondyle of humerus and posterior border of ulna
• Insertion: Fifth metacarpal
• Action: Extends and adducts hand
Extensor Carpi Ulnaris
Posterior, Superficial Layer
34
• Origin: Lateral epicondyle of humerus
• Insertion: Extensor expansion of little finger
• Action: Extends 5th digit and hand
Extensor Digiti Minimi
Posterior, Middle Layer
35
• Origin: Lateral epicondyle of humerus, supinator crest of ulna
• Insertion: Lateral surface and posterior border of radius
• Action: Supinates forearm
Supinator
Posterior, Deepest Layer
36
• Origin: Posterior surface of ulna and radius, and interosseous membrane
• Insertion: First metacarpal
• Action: Abducts thumb and hand
Abductor Pollicis Longus
Posterior, Deepest Layer
37
• Origin: Middle third of radius and interosseous membrane
• Insertion: Base of proximal phalanx of thumb
• Action: Extends thumb
Extensor Pollicis Brevis
Posterior, Deepest Layer
38
• Origin: Middle third of ulna and interosseous membrane
• Insertion: Base of distal phalanx of thumb
• Action: Extends thumb
Extensor Pollicis Longus
Posterior, Deepest Layer
39
The End
