Muscles Of The Dog Forelimb

Question 1

Name the 8 extrinsic muscles of the forelimb

Answer 1

1. Trapezius
2. Rhomboideus
3. Omotransversarius
4. Serratus ventralis
5. Latissimus dorsi
6. brachiocephalicus
7. superficial pectoral
8. deep pectoral

Question 2

What is the muscular attachment between the limb and trunk called in domestic species?

Answer 2

OMOTHORACIC junction and is a synsarcosis

Question 3

Describe the origin ad insertion of the trapezium

Answer 3

Made up of 2 parts
Entire muscle originates from the median raphe of the neck (C3-T9) and inserts onto the scapula spine
PARTS OF THE ORIGIN AND INSERTION ARE BY WAY OF A APONEUROSIS

Question 4

Describe the action and innervation of the trapezius muscle

Answer 4

Action- abducts and elevates the forelimb

Innervation-accessory nerve

Question 5

Describe the origin and insertion of the latissimus dorsi

Answer 5

Originates from the thoracolumar fascia (spinous processes of the lumbar and T7/8)
Inserts on the teres major tuberosity of the humerus

Question 6

Describe the action ad innervation of the latissimus dorsi

Answer 6

Action- retraction of the forelimb, flex the shoulder joint

Innervation by thoracodorsal nerve (C7,C8 AND T1)

Question 7

Describe the origin and insertion of the omotransversarius

Answer 7

OMO=SHOULDER TRANSVERSE= PROCESS OF THE CERVICAL VERTEBRAE

Originates at he transverse process of the 1st cervical vertebrae ad inserts onto the distal part of the scapula spine and acromion

Question 8

Describe the action and innervation of the omotransversarius

Answer 8

Action- protraction of the limb, flexes the back laterally

Innervation= accessory nerve

Question 9

Describe the origin and innervation of the rhomboideus

Answer 9

Divided into 2 parts
STRONGER CERVICAL PART- originates from the median raphe of the neck and extends to the spinal processes of the first 3 thoracic vertebrae
THORACIC PART-originates from the spinous processes of the 4th to 7th thoracic vertebrae

Innervation- both parts insert on the dorsal border (BOTH MEDIALLY AD LATERALLY) of the scapula

Question 10

Describe the action and innervation of the rhomboideus

Answer 10

Action- to elevate the limb ad to draw the scapula against the trunk
Innervation- cervical and thoracic nerves

Question 11

Describe the origin and insertion of the serratus ventralis

Answer 11

Named after its serrated shape and ventral position

Originates from the transverse processes of the last 5 cervical vertebrae and the ventral part of the last 8 ribs. It inserts onto the faces serrata of the scapula

Question 12

Describe the action and innervation of the serratus ventralis

Answer 12

Action- retractor/ protractor of the limb, support the limb and trunk,inspiration
Innervation- cervical nerves and long thoracic nerve

Question 13

Describe the origin and innervation of the brachiocephalicus

Answer 13

Has 3 parts divided by the VESTIGIAL CLAVICLE
Proximal to the clavicle are the cleidomastoideus muscle from the neck and the cleidocervicalis from the neck
COLLECTIVELY, THESE 2 MUSCLES ARE CALLED THE CLEIDOCEPHALICUS and are innervated by the cervical and accessory nerves

Distal to the clavicle, cleidobranchialis runs to the humerus and is innervated by the axillary nerve

Question 14

Describe the action of the brachiocephalicus

Answer 14

To protract the limb

Question 15

Describe the origin and insertion of the superficial pectoral

Answer 15

Originates from the cranial end of the sternum to the third costal cartilage and inserts on the major tubercle of the humerus

Question 16

Describe the action and innervation of the superficial pectoral

Answer 16

Action-adducts the limb

Innervation- cranial pectoral nerve

Question 17

Describe the origin and insertion of the deep pectoral

Answer 17

LARGER OF THE 2 PECTORALS

Originates from the entire length of the sternum and inserts on the minor tubercle (lesser tubercle) of the humerus

Question 18

Describe the action and innervation of the deep pectorals

Answer 18

Action-to advance the trunk onto the limb and retract and adduct the limb
Innervation- caudal pectoral nerve

Question 19

Describe the origin and insertion of the deltoideus

Answer 19

Muscle comprises of 2 parts
THE SCAPULA PART ARISES FROM A WIDE APONEUROSIS ARISING FROM THE SPINE OF THE SCAPULA, COVERING INFRASPINATUS MUSCLE

Originates from the spine and acromial process of the scapula and inserts onto the deltoid tuberosity

Question 20

Describe the action and innervation of the deltoideus muscle

Answer 20

Action is to flex the shoulder

Innervation by the axillary nerve

Question 21

Describe the origin and insertion of the long head of the tricep

Answer 21

Origin=the caudal border of the scapula

Insertion=olecranon tuber

Question 22

Describe the action and innervation of the long head of the tricep

Answer 22

Action= to extend the elbow and flex the shoulder 
Innervation= the radial nerve

Question 23

Describe the origin and insertion of the lateral head of the tricep

Answer 23

Origin= the tricepital line of the humerus

Inserts on the olecranon tuber

Question 24

Describe the action and innervation of the lateral head of the tricep

Answer 24

Action=to extend the elbow

Innervation= the radial nerve

Question 25

Describe the origin and insertion of the accessory and medial head of the tricep. What is its action and innervation?

Answer 25

Origin= the proximal third of the humerus Inserts on the olecranon tuber of the ulna Action=extensor of the elbow Innervation= radial nerve

Question 26

Describe the origin and insertion of the supraspinatus muscle

Answer 26

SUPRA= SUPERIOR TO SPINATUS= SPINE ``` Origin= arises from and fills the supraspinous fossa Inserts= by way of a short tendon on the major tubercle of the humerus ```

Question 27

Describe the action and innervation of the supraspinatus

Answer 27

Action- extension of the shoulder and the tendon acts as a lateral collateral ligament to stabilise the shoulder joint Innervation- suprascapular nerve

Question 28

Describe the origin and insertion of the infraspinatus muscle

Answer 28

Infra=inferior to ``` Origin= originates and fills the infraspinous fossa Inserts= distal to the greater tubercle of the humerus ```

Question 29

Describe the action and innervation of the infraspinatus

Answer 29

Action- can flex or extend the shoulder joint depending on limb position, tendon acts as a lateral collateral ligament to stabilise the shoulder joint Innervation- suprascapular nerve

Question 30

Describe the origin and insertion of the teres minor

Answer 30

Origin=arises from the distal 3rd of the caudal edge of the scapula Inserts= proximal to the deltoid tuberosity

Question 31

Describe the action and innervation of the teres minor

Answer 31

Action-lateral shoulder joint capsule muscle | Innervation by axillary nerve

Question 32

Describe the origin and insertion of the biceps branchii

Answer 32

Originates by the way of a long tendon on the supraglenoid tuberosity, it then crosses the shoulder joint, runs craniomedially down the brachium and inserts, by way of 2 tendons onto the radius and ulna

Question 33

Describe the action and innervation of the biceps brachii

Answer 33

Action= flexor of the elbow, extensor of the shoulder | Innervation=musculocutaneous nerve

Question 34

Describe the origin and insertion of the brachialis

Answer 34

``` Origin= the proximal caudal humerus Inserts= the proximal ulna ```

Question 35

Describe the action and innervation of the branchialis

Answer 35

Action-flexor of the elbow | Innervation-musculocutaneous nerve

Question 36

Describe the origin and insertion of the coracobranchialis

Answer 36

Origin=coracoid process of the scapula | Inserts= minor tubercle of the humerus

Question 37

Describe the action and innervation of the coracobranchialis

Answer 37

Action= the medial capsular muscle of the shoulder joint | Innervation=musculocutaneus

Question 38

Describe the origin and insertion of the anconeus

Answer 38

Origin=caudal third of the humerus | Inserts= on the olecranon

Question 39

Describe the action and innervation of the anconeus

Answer 39

Action= elbow extensor and capsular muscle of the elbow | Innervation=radial nerve

Question 40

Describe the origin and insertion of the tensor fascia antebrachii

Answer 40

Origin=arises from the latissimus dorsi | Inserts= on the olecranon

Question 41

Describe the action and innervation of the tensor fascia antebrachii

Answer 41

Action- this broad flat muscle is the main tensor of the antebrachial fascia Innervation- radial nerve

Question 42

Describe the origin and insertion of the extensor carpi radialis

Answer 42

Originates at the lateral condyle/ supracondylar crest of the humerus Inserts on the proximal-dorsal surface of metacarpal II and III

Question 43

What is the action and innervation of the extensor carpi radialis?

Answer 43

Action-extensor of the carpus, flexor of the elbow | Innervation-radial nerve

Question 44

Describe the origin and insertion of the common digital extensor

Answer 44

Origin=lateral epicondyle of the humerus | Inserts=the distal phalanges of digits II to V

Question 45

Describe the action and insertion of the common digital extensor

Answer 45

Action-extends carpus and digits II to V | Innervation via the radial nerve

Question 46

Describe the origina and insertions of the lateral digital extensor. Describe its action and innervations

Answer 46

Originates from the lateral epicondyle of the humerus Inserts on the distal phalanges of digits III,IV and V Innervation-radial nerve Action- extension of digits II,IV and V

Question 47

Describe the origin and insertion of the ulnaris lateralis

Answer 47

Origin=from lateral epicondyle of humerus | Inserts= on the proximal end of metacarpal V

Question 48

Describe the action and innervation of the ulnaris lateralis

Answer 48

Action= extension or flexion of the carpus, depending on the position of the limb Innervation via the radial nerve

Question 49

Describe the origin and insertion of the supinator

Answer 49

Origin- lateral collateral ligament and the lateral epicondyle of the humerus Inserts-cranial surface of the radius THE MUSCLE LIES LATERALLY ON THE CRANIAL SURFACE OF THE ELBOW

Question 50

Describe the action and innervation of the supinator

Answer 50

Action- rotation of the paw so that the palmer surface faces medially Innervation-radial nerve

Question 51

Describe the origin and insertion of the abductor pollicis longus

Answer 51

Origin-craniolateral surface of the ulna | Inserts- medial aspect of the proximal end of metacarpal I/II lt has a small SESAMOID near the point of insertion

Question 52

Describe the action and innervation of the abductor pollicis longus

Answer 52

Action-extends carpus and abduct the 1st digit | Innervation-radial nerve

Question 53

Describe the origin and insertion of the pronator teres

Answer 53

Origin-medial epicondyle of the humerus Inserts- cranial radius MUSCLE LIES MEDIALLY ON THE CRANIAL SURFACE OF THE ELBOW

Question 54

Describe the action and innervation of the pronator teres

Answer 54

Action=rotation of the paw so that the palmer surface is in contact with the ground Innervation- median nerve

Question 55

Describe the origin and insertion of the flexor carpi radialis

Answer 55

``` Origin= medial epicondyle of the humerus Inserts= the palmer aspect of metacarpals II and III ```

Question 56

Describe the action and insertion of the flexor carpi radialis

Answer 56

Action=flexor of the carpus | Innervation=median nerve

Question 57

Describe the origin and insertion of the superficial digital flexor

Answer 57

Origin=medial epicondyle of the humerus | Inserts= the palmer proximal edge of the middle phalanx of all digits

Question 58

Describe the action and innervation of the superficial digital flexor

Answer 58

Action= flexor of the digits | Innervation=median nerve

Question 59

Describe the origin and insertion of the flexor carpi ulnaris

Answer 59

Muscle has 2 heads WEAKER ULNAR HEAD: originates from the proximal ulna STRONG HUMERAL HEAD: originates from the medial epicondyle of the humerus Both insert onto the accessory carpal bone

Question 60

Describe the action and innervation of the flexor carpi ulnaris

Answer 60

``` Action= flexor of the carpus Innervation= ulnar nerve ```

Question 61

Describe the origin and insertion of the deep digital flexor

Answer 61

Has 3 heads HUMERAL HEAD: strongest and consists of 3 bellies. Arises from the medial epicondyle of the humerus RADIAL HEAD: weakest division and arises from the medial border of the radius ULNAR HEAD: arises from the caudal border of the ulna All 3 heads unite to form one strong tendon which then splits and inserts on the distal phalanges of all digits

Question 62

Describe the action and innervation of the deep digital flexor

Answer 62

Action= flexor of all digits | Innervation=median nerve

Question 63

Describe the origin and insertion of the pronator quadratus

Answer 63

Origin=ulna Inserts= radius Muscle fills the space between the radius and ulna

Question 64

Describe the action and innervation of the pronator quadratus

Answer 64

Action=rotate the paw inwards | Innervation=median nerve

Question 65

Describe the origin and insertion of the interosseousei/ interossei

Answer 65

4 in total lying on the palmer aspect of the metacarpal bones II, III, IV and V Distally, each muscle divides into 2 short tendons that attach to the proximal end of phalange 1 Each tendon has a SESAMOID embedded in it

Question 66

Describe the action and innervation of the interosseousei/ interossei

Answer 66

Action= flexion of the metacarpophalangeal joints | Innervation via the ulna nerve