Intrinsic muscles of the forelimb

Question 1

Supraspinatus

Answer 1

Origin: supraspinous fossa, part of the spine of the scapula, and neck of the scapula.

Insertion: major tubercle of the humerous.

Innervation: Suprascapular nerve.

Action: extension of the shoulder

Question 2

Infraspinatus

Answer 2

Origin: Infraspinous fossa, spine of the scapula

Insertion: Lateral aspect of greater tubercle of the humerous.

Innervation: Suprascapular nerve

Action: flexes the shoulder and some abduction

Question 3

Teres Minor

Answer 3

Origin: Infraglenoid tubercle

Insertion: Tricipital line proximal to deltoid tuberosity.

Innervation: Axillary nerve

Action: flexion of the shoulder

Question 4

Deltoideus

Answer 4

Origin: Acromiun and spine of the scapula

Insertion: Deltoid tuberosity

Innervation: Axillary nerve

Action: Flexion, maybe abduction

Question 5

Subscapularis

Answer 5

Origin: Subscapular fossa of the scapula

Insertion: lesser tubercle of the humerous

Insertion: Subscapular and axillary nerves

Action: minor adduction, maybe some flexion and extension

Question 6

Teres Major

Answer 6

Origin: Caudal angle of the scapula

Insertion: Teres tubercle

Innervation: axillary nerve

Action: flexion

Question 7

Corachobrachialis

Answer 7

Origin: Coracoid process

Insertion: close to teres tubercle

Innervation: musculocutaneous nerve

Action: it is a vestigial muscle…may help to extend shoulder

Question 8

Triceps Brachii

Answer 8

Origin: Long head from the caudal border of the scapula, lateral head from tricipital line,
medial head from proximal medial shaft close to teres tubercle, and accessory head from
neck of the humerus.

Insertion: olecranon

Innervation: radial nerve

Action: flexes shoulder and extends elbow

Question 9

Tensor fasciae antebrachii

Answer 9

Origin: from the latissimus dorsi

Insertion: Olecranon

Innervation: radial nerve

Action: elbow extension

Question 10

Biceps brachii

Answer 10

origin: supraglenoid tubercle
insertion: radial and ulnar tuberosities
innervation: musculocutaneous nerve
action: flexion of elbow and extension of shoulder

Question 11

Brachialis

Answer 11

Origin: caudal aspect and neck of the radius

Insertion: radial and ulnar tuberosities

Innervation: musculocutaneous nerve

Action: flex elbow

Question 12

Anconeus

Answer 12

Origin: Lateral epicondylar crest, lateral epicondyle, partly fromthemedial epicondyle.

Insertion: proximolateral aspect of the ulna

Innervation: radial nerve

Action: elbow extension