Intrinsic Muscles

Front 1

Back 1

Deltoideus m. -- Scapula part and acromial part

Action: flex the shoulder joint

Front 2

Back 2

Infraspinatus m.

Action:

1. extend or flex shoulder joint (depends on position of limb);

2. laterally stabilize and abduct shoulder joint

Front 3

Back 3

Bursa of infraspinatus m.

Front 4

Lateral view

Back 4

Teres minor m.

Action:

1.flex the shoulder joint;

2. rotate shoulder laterally,

3. prevent medial rotation when bearing weight

Front 5

Lateral view

Back 5

Teres minor m.

Action:

1.flex the shoulder joint;

2. rotate shoulder laterally,

3. prevent medial rotation when bearing weight

Front 6

Back 6

Supraspinatus m.

Action: extend and stabilize the shoulder joint

Front 7

Lateral view

Back 7

Supraspinatus m.

Action: extend and stabilize the shoulder joint

Front 8

Back 8

Subscapularis m.

Action:

1. adduct, extend and medially stabilize shoulder

2. flex shoulder joint

3. rotate shoulder medially, prevent lateral rotation when bearing weight

Front 9

Back 9

Supraspinatus m.

Action: extend and stabilize the shoulder joint

Front 10

Back 10

Teres major m.

Action:

1. Flex the shoulder joint

2. Rotate the shoulder medially

Front 11

Medial view

Back 11

Teres major m.

Action:

1. Flex the shoulder joint

2. Rotate the shoulder medially

Front 12

Medial view

Back 12

Coracobrachialis m.

Action:

1. adduct, extend, and stabilize the shoulder joint

Front 13

Back 13

Coracobrachialis m.

Action:

1. adduct, extend, and stabilize the shoulder joint

Front 14

Back 14

Tenso fasciae antebrachii m.

Action:

1. Extend the elbow

Front 15

Back 15

Tensor fasciae antebrachii m.

Action:

1. Extend the elbow

Front 16

Back 16

Triceps brachii m.

Action:

1. Long head: flex the shoulder joint, extend the elbow

2. Lateral, accessory and medial heads: extend the elbow

Front 17

Back 17

Triceps brachii m. Long head

Action:

1. flex the shoulder joint,

2. extend the elbow

Front 18

Back 18

Triceps brachii m. medial head

Action:

extend the elbow

Front 19

Back 19

Triceps brachii m. long head

Action

1. extend the elbow,

2. flex the shoulder joint

Front 20

Back 20

Triceps brachii m. lateral head

Action:

Extend the elbow

Front 21

Back 21

Triceps brachii m. lateral head

Action:

extend the elbow

Front 22

Back 22

Triceps brachii m. long head

Action:

1. Extend the elbow

2. flex the shoulder joint

Front 23

Back 23

Triceps brachii m. accessory head

Action:

extend the elbow

Front 24

Back 24

Triceps brachii m. medial head

Action:

extend the elbow

Front 25

Back 25

Anconeus m.

Action:

extend the elbow

Front 26

Back 26

Epitrochleonanconeus m.

***ONLY IN CAT***

***associated with supracondylar foramen medially

Front 27

Back 27

Biceps brachii m.

Action:

1. extend the shoulder joint

2. flex the elbow

**No attachment to humerus

Front 28

Back 28

Transverse humeral retinaculum (ligament)Tr

Front 29

Back 29

Biceps brachii m.

Action:

1. extend the shoulder joint

2. flex the elbow

**No attachment to humerus

Front 30

Medial view

Back 30

Transverse humeral retinaculum (ligament)

Front 31

Back 31

Intertubercular (bicipital) bursa/intertubercular synovial sheath

**not a true bursa

Front 32

Medial view

Back 32

Intertubercular (bicipital) bursa/intertubercular synovial sheath

**not a true bursa

Front 33

Back 33

Brachialis m.

Action:

Flex the elbow

Front 34

Back 34

Brachialis m.

Action:

flex the elbow

Front 35

Deltoideus m. scapula part

Back 35

O: spine of scapula via aponeurosis

I: deltoid tuberosity of humerus

Nerve: axillary n.

Front 36

Deltoideus m. acromial part

Back 36

O: acromion of scapula

I: deltoid tuberosity

Nerve: axillary

Front 37

Infraspinatus m.

Back 37

O: infraspinous fossa of scapula

I: circumscribed area of greater tubercle of humerus

Nerve: suprascapular n.

Front 38

Teres minor m.

Back 38

O: infraglenoid tubercle and distal 3rd of caudal border of scapula

I: teres minor tuberosity of humerus

Nerve: Axillary n.

Front 39

Supraspinatus m.

Back 39

O: Supraspinous fossa of scapula

I: greater tubercle of humerus
Nerve: suprascapular n.

Front 40

Subscapularis m.

Back 40

O: Subscapular fossa of scapula

I: Lesser tubercle of the humerus

Nerve:

1. subscapular n.

2. axillary n. (small area, caudal part of m.)

Front 41

Teres major m.

Back 41

O: Caudal angle/caudal border of scapula, caudal surface of subscapularis

I: teres major tuberosity of humerus

Nerve: axillary n.

Front 42

Coracobrachialis m.

Back 42

O: Corocoid process of scapula
I: crest of lesser tubercle of humerus

Nerve: Musculocutaneous n.

Front 43

Tensor fasciae antebrachii m.

Back 43

O: Fascia on lateral side of latissimus dorsi m.

I: Olecranon
Nerve: Radial n.

Front 44

Triceps brachii m. long head

Back 44

O: Caudal border of scapula

I: Olecranon

Nerve: Radial n.

Front 45

Triceps brachii m. lateral head

Back 45

O: Tricipital line of humerus

I: Olecranon

Nerve: Radial n.

Front 46

Triceps brachii m. accessory head

Back 46

O: neck of humerus

I: Olecranon

Nerve: Radial n.

Front 47

Triceps brachii m. medial head

Back 47

O: Crest of lesser tubercle of humerus near teres major tuberosity

I: Olecranon

Nerve: Radial n.

Front 48

Anconeus m.

Back 48

O: lateral supracondylar crest of humerus, lateral and medial epicondyles of humerus

I: lateral surface of proximal end of ulna

Nerve: Radial n.

Front 49

Biceps brachii m.

Back 49

O: Supraglenoid tubercle of scapula

I: Dog - ulnar and radial tuberosities

Cat - radial tuberosity ONLY

Nerve: musculocutaneous n.

Front 50

Brachialis m.

Back 50

O: Proximal third of lateral surface of humerus

I: Dog - ulnar and radial tuberosity

Cat - ulnar tuberosity

Nerve: musculocutaneous n.