Canine Forelimb-Muscles

Question 1

Trapezius

Answer 1

Cranial extrinsic muscle

Function: raises scapula, helps in limb advancement

Nerve: accessory nerve

Question 2

Omotransversarius

Answer 2

Cranial extrinsic muscle, atlas to acromion of scapula

Function: helps advance limb

Nerve: accessory nerve

Question 3

Brachiocephalicus

Answer 3

Cranial extrinsic muscle, contains clavicle

Function: When limb is fixed it draws head ventrally; advances free limb

Nerve: accessory nerve

Question 4

Lattissimus dorsi

Answer 4

Caudal extrinsic muscle, across thoracolumbar area, inserts on humerus

Function: hold scapula against chest, retracts free forelimb; when forelimb is fixed/weight-bearing helps draw body forward

Nerve: brachial plexus nerve branch (thoracodorsal nerve)

Question 5

Rhomboideus

Answer 5

Dorsal extrinsic muscle, under the trapezius, attaches to dorsal medial scapula

Function: raising and retracting limb

Nerve: brachial plexus nerve branch

Question 6

Superficial pectoral

Answer 6

Ventral extrinsic muscle, sternum to humerus

Function: adduct limb or hold it against the body

Nerve: brachial plexus nerve branches

Question 7

Deep pectorals

Answer 7

Ventral extrinsic muscle, sternum to humerus

Function: acts to sling trunk between forelimbs, retracts free forelimb, advances trunk against planted forelimb

Nerve: brachial plexus nerve branches

Question 8

Serratus Ventralis

Answer 8

Medial extrinsic muscle, cervical vertebrae to lower ribs

Function: supports weight of trunk, advance and retract limb (depends on which portion is activated and position limb is in)

Nerve: brachial nerve plexus nerve branch (long thoracic nerve)

Question 9

Supraspinatus and Infraspinatus

Answer 9

Lateral intrinsic muscles, fill fossae in scapula

Function: support shoulder joint laterally

Nerve: suprascapular nerve

Question 10

Subscapularis

Answer 10

Medial intrinsic muscle, medial scapula to humerus

Function: supports the shoulder joint medially, adducts limb

Nerve: subscapular nerve

Question 11

Deltoideus

Answer 11

caudal intrinsic muscle, scapula to deltoid tuberosity of humerus

Function: flexes shoulder joint

Nerve: axillary nerve

Question 12

Teres major and minor

Answer 12

caudal intrinsic muscles, scapula to teres tuberosity on humerus

Function: flexes shoulder joint

Nerve: axillary nerve

Question 13

Triceps brachii

Answer 13

Four heads (long, lateral, medial, accessory), run from scapula/humerus to ulna olecranon, cushioned by tricipital bursa

Function: extends elbow

Nerve: radial nerve

Question 14

Tensor fasciae antebrachii

Answer 14

scapula to olecranon, lies over long head of triceps

Function: extends elbow

Nerve: radial nerve

Question 15

Anconeus

Answer 15

distal humerus to olecranon, part of elbow joint capsule

Function: extends elbow

Nerve: radial nerve

Question 16

Biceps brachii

Answer 16

scapula to proximal radius and ulna

Function: flexes elbow

Nerve: musculotaneous nerve

Question 17

Brachialis

Answer 17

proximal humerus to proximal radius

Function: flexes elbow

Nerve: musculotaneous nerve

Question 18

Extensor carpi radialis

Answer 18

starts at lateral epicondyle inserts on MC3, most medial of extensor group

Function: extends carpus

Nerve: radial nerve

Question 19

Ulnaris lateralis

Answer 19

starts at lateral epicondyle, inserts on accessory carpal bone and MC5

Function: extends carpus

Nerve: radial nerve

Question 20

Extensor carpi oblique

Answer 20

also called abductor pollicis longus, lateral epicondyle to medial aspect of MC2

Function: extends carpus

Nerve: radial nerve

Question 21

Common digital extensor

Answer 21

Lateral epicondyle to each digit

Function: extends carpus

Nerve: radial nerve

Question 22

Lateral digital extensor

Answer 22

Runs along edge of common digital extensor (shares common insertion on lateral-most digits)

Function: extends carpus

Nerve: radial nerve

Question 23

Flexor carpi radialis

Answer 23

most medial muscle, medial epicondyle to MC2

Function: flexes carpus

Nerve: median or ulnar nerves

Question 24

Flexor carpi ulnaris

Answer 24

more lateral muscle, medial epicondyle to accessory carpal bone

Function: flexes carpus

Nerve: median or ulnar nerves

Question 25

Superficial digital flexor

Answer 25

caudomedial antebrachium, inserts around P1-P2 of each digit Function: flexes carpus Nerve: median or ulnar nerves

Question 26

Deep digital flexor

Answer 26

each branch perforates superficial digital flexor as it passes distally to insert on palmar aspect of P3 of each digit Function: flexes carpus Nerve: median or ulnar nerves