1. Muscles Martini Chapter 11
Lab Activity 11: Group II
Muscles
Martini Chapter 11
Portland Community College
BI 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.

3. MUSCLES OF THE SHOULDER AND ARM

4. 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

5. Supraspinatus Origin: Supraspinous fossa
Insertion: Greater tubercle of humerus
Action: Abducts humerus

6. Infraspinatus Origin: Infraspinous fossa
Insertion: Greater tubercle of humerus
Action: Rotates humerus laterally

7. Teres Minor Origin: Axillary border of scapula
Insertion: Greater tubercle of humerus
Action: Rotates humerus laterally

8. Teres Major Origin: Axillary border at inferior angle of scapula
Insertion: Intertubular groove of humerus
Action: Extends, adduction and medial rotates humerus.

9. Subscapularis Origin: Subscapular fossa
Insertion: Lesser tubercle of humerus
Action: Rotates humerus medially

10. Biceps Brachii
Short Head
Origin: Long head, supraglenoid tubercle; Short head, coracoid process scapula
Insertion: Radial tuberosity of the radius
Action: Flexes radius and humerus, and supinates forearm
Long Head

11. Coracobrachialis Origin: Coracoid process of scapula
Insertion: Middle third of humerus
Action: Flexes and adducts humerus

12. 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

13. Brachialis Origin: Anterior distal two-thirds of humerus
Insertion: Coronoid process of ulna
Action: Flexes ulna

14. Anconeus Origin: Lateral epicondyle of humerus
Insertion: Olecranon process, posterior surface of ulna
Action: Weak extensor of ulna, stabilizes elbow joint in extension

15. MUSCLES OF THE PALM

16. Abductor Pollicis Brevis
Origin: Scaphoid and trapezium
Insertion: Proximal phalanx of thumb
Action: Abducts thumb and aids in flexion
Palm

17. Flexor Pollicis Brevis
Origin: Trapezium
Insertion: Proximal phalanx of thumb
Action: Flexes thumb
Palm
Palm

18. Flexor Digiti Minimi Origin: Hook of hamate
Insertion: Proximal phalanx of fifth digit
Action: Flexes fifth digit
Palm
Palm

19. Abductor Digiti Minimi
Origin: Pisiform and tendon of flexor carpi ulnaris
Insertion: Proximal phalanx of fifth digit
Action: Abducts fifth digit
Palm
Palm

20. MUSCLES OF ANTERIOR FOREARM

21. 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

22. Flexor Carpi Radialis Origin: Medial epicondyle of humerus
Insertion: Base of second metacarpal
Action: Flexes wrist and elbow and abducts wrist
Anterior, Superficial Layer

23. Palmaris Longus Origin: Medial epicondyle of the humerus
Insertion: Palmar aponeurosis
Action: Weak flexion of wrist, tenses skin of palm
Anterior, Superficial Layer

24. 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

25. Flexor Digitorum Superficialis
Origin: Medial epicondyle of humerus and coronoid process of ulna
Insertion: Middle phalanges of fingers
Action: Flexes fingers and wrist
Anterior, Middle Layer

26. Flexor Digitorum Profundus
Origin: Anterior and medial surfaces of ulna and interosseous membrane
Insertion: Distal phalanges of fingers
Action: Flexes fingers and wrist
Anterior, Deepest Layer

27. Flexor Pollicis Longus
Origin: Middle half of radius, interosseous membrane, coronoid process of ulna
Insertion: Distal phalanx of thumb
Action: Flexes thumb and wrist
Anterior, Deepest Layer

28. MUSCLES OF POSTEROLATERAL FOREARM

29. Brachioradialis Origin: Lateral supracondylar ridge
Insertion: Styloid process of radius
Action: Flexes forearm
Posterior, Superficial Layer

30. Extensor Carpi Radialis Longus
Origin: Lateral supracondylar ridge of humerus
Insertion: Second metacarpal
Action: Extends and abducts hand
Posterior, Superficial Layer

31. Extensor Carpi Radialis Brevis
Origin: Lateral epicondyle of humerus
Insertion: Third metacarpal
Action: Extends and abducts hand
Posterior, Superficial Layer

32. Extensor Digitorum Origin: Lateral epicondyle of humerus
Insertion: Into distal phalanx by 4 tendons
Action: Extends fingers and hand
Posterior, Superficial Layer

33. Extensor Carpi Ulnaris
Origin: Lateral epicondyle of humerus and posterior border of ulna
Insertion: Fifth metacarpal
Action: Extends and adducts hand
Posterior, Superficial Layer

34. Extensor Digiti Minimi
Origin: Lateral epicondyle of humerus
Insertion: Extensor expansion of little finger
Action: Extends 5th digit and hand
Posterior, Middle Layer

35. Supinator
Origin: Lateral epicondyle of humerus, supinator crest of ulna
Insertion: Lateral surface and posterior border of radius
Action: Supinates forearm
Posterior, Deepest Layer

36. Abductor Pollicis Longus
Origin: Posterior surface of ulna and radius, and interosseous membrane
Insertion: First metacarpal
Action: Abducts thumb and hand
Posterior, Deepest Layer

37. Extensor Pollicis Brevis
Origin: Middle third of radius and interosseous membrane
Insertion: Base of proximal phalanx of thumb
Action: Extends thumb
Posterior, Deepest Layer

38. Extensor Pollicis Longus
Origin: Middle third of ulna and interosseous membrane
Insertion: Base of distal phalanx of thumb
Action: Extends thumb
Posterior, Deepest Layer

39. The End
The End