Thoracic Limb: Origin, Insertion, Action, Innervation

Question 1

Two superficial pectoral muscles with ORIGINS and INSERTIONS

Answer 1

1) Descending pectoral
ORIGIN-1st sternebrae
INSERTION-crest of greater tubercle of humerus

2)Transverse pectoral
ORIGIN-2nd/3rd sternebrae
INSERTION-crest of greater tubercle

Question 2

ACTION of superficial pectoral muscles

Answer 2

ACTION: Adduct limb when it’s not bearing weight or prevent limb from being abducted when bearing weight.

Question 3

Deep pectoral ORIGIN and INSERTION

Answer 3

O-Ventral part of sternum and fibrous part of raphe

I-Majority (tendinous) on lesser tubercle

Question 4

Deep pectoral ACTION

Answer 4

Pull trunk cranially and extend shoulder joint (supporting wt). If not supporting wt, to abduct and flex shoulder jt.

Question 5

Two muscles that make up the brachiocephalicus ORIGIN and INSERTION

Answer 5

1)Cleidobrachialis
O- clavicle
I-Distal end of cranial border of humerus

2)Cleidocephalicus
O-clavicle
I-Clavicular tendon to the neck and head

Question 6

Two parts of cleidocephalicus

Answer 6

1-cleidocervicalis: attaches to mid-dorsal fibrous raphe and nuchal crest of occipital bone.
2-cleidomastoideus: attaches to mastoid process of temporal bone

Question 7

Omotransversarius attachment

Answer 7

Distal end of spine of scapula and transverse wing of atlas

Question 8

Omotransversarius ACTION

Answer 8

Advance limb or flex neck laterally

Question 9

Two parts of tapezius muscle

Answer 9

1-Cervical: cranial to aponeurosis

2-Thoracic: caudal to aponeurosis

Question 10

Trapezius ORIGIN and INSERTION

Answer 10

O-Median raphe of neck and supraspinous ligament from C3 to T9.
I-Spine of scapula

Question 11

Three parts of the rhomboideus muscle

Answer 11

1-rhomboideus capitis:attaches cranial dorsal border of scapula to nuchal crest of occipital bone
2-rhomboideus cervicis: runs from median raphe of neck to dorsal border of scapula
3-rhomboideus thoracis- connects spines of T vertebrae to dorsal border of scapula.

Question 12

Rhomboideus ORIGIN and INSERTION

Answer 12

O-Nuchal crest of occipital bone, median raphe of neck, spinous process of first 7 T vertebrae
I-dorsal border of scapula

Question 13

Lastissimus dorsi ORIGIN and INSERTION

Answer 13

O-Spinous process of lumbar and last 7/8 TVert and muscular attachment to last 2 or 3 ribs
I-Teres major tuberosity of humerus and teres major tendon

Question 14

Rhomboideus ACTION

Answer 14

Elevate forelimb and draw scapula against trunk

Question 15

Latissimus dorsi ACTION

Answer 15

Flex shoulder joint- create digging action.

Question 16

Serratus ventralis cervicis and serratus ventralis thoracis ORIGIN and INSERTION

Answer 16

O-Transverse processes of last 5 C vert and first 7/8 ribs ventral to their midlline
I-Dorsomedial third of serrated face of scapula

Question 17

Trapezius action

Answer 17

To elevate and abduct the forelimb

Question 18

Supraspinatus ORIGIN and INSERTION

Answer 18

O-supraspinous fossa

I-> tubercle of the humerus by a thick tendon

Question 19

Supraspinatus ACTION

Answer 19

To extend and laterally stabilize the shoulder joint

Question 20

Teres minor ORIGIN and INSERTION

Answer 20

O-Infraglenoid tubercle and distal 3rd of caudal border of spine
I-Teres minor tuberosity of humerus

Question 21

Teres major ACTION

Answer 21

Flex the shoulder, rotate the shoulder laterally, and prevent medialrotation when weight bearing.

Question 22

Name the four parts of the triceps brachii

Answer 22

1-Long head
2-Lateral head
3-Accessory head
4-Medial head

Question 23

Triceps brachii- long head ORIGIN and INSERTION

Answer 23

O-Caudal border of scapula

I-Olecranon tuber

Question 24

Triceps brachii-long head ACTION

Answer 24

Extend elbow and flex the shoulder

Question 25

Triceps brachii-lateral head ORIGIN and INSERTION

Answer 25

O-Tricipital line of the humerus | I-Olecranon tuber

Question 26

Tricpes brachii- lateral head ACTION

Answer 26

Extend elbow

Question 27

Triceps brachii- accessory head ORIGIN and INSERTION

Answer 27

O-Neck of the humerus | I-Olecranon tuber

Question 28

Triceps brachii-accessory head ACTION

Answer 28

Extend elbow

Question 29

Triceps brachii- medial head ORIGIN and INSERTION

Answer 29

O-Crest of the lesser tubercle near the teres major tuberosity I-Olecranon

Question 30

Triceps brachii- medial head ACTION

Answer 30

Extend elbow

Question 31

Brachiocephalicus ACTION

Answer 31

Advance limb, extend shoulder joint, and draw neck to the side.

Question 32

Biceps brachii ORIGIN and INSERTION

Answer 32

O-Supraglenoid tubercle | I-The ulnar and radial tuberosties

Question 33

Biceps brachii ACTION

Answer 33

Flex elbow and extend shoulder

Question 34

Extensor carpi radialis ORIGIN and INSERTION

Answer 34

O-Lateral supracondylar crest | I-Small tuberosities on the dorsal surfaces of the base of metacarpals II and III.

Question 35

Extensor carpi radialis ACTION

Answer 35

Extend carpus

Question 36

Common digital extensor ORIGIN and INSERTION

Answer 36

O-Lateral epicondyle of humerus | I-Extensor processes of the distal phalanges of digits II,III,IV,V

Question 37

Common digital extensor ACTION

Answer 37

Extend joints of the four principal digits (2-5) and the carpus

Question 38

Superficial digital flexor ORIGIN and INSERTION

Answer 38

O-Medial epicondyle of the humerus | I-Palmar surface of the proximal end of middle phalanges of digits 2-5

Question 39

Superficial digital flexor ACTION

Answer 39

Flex carpal, metacarpophalangeal, and proximal interphalangeal joints of digits 2-5.

Question 40

Flexor carpi ulnaris: two parts ORIGIN and INSERTION

Answer 40

Ulnar head: caudal border/medial surface of olecranon Humeral head:medal epicondyle of the humerus Insertion-accessory carpal bone

Question 41

Flexor carpi ulnaris ACTION

Answer 41

Flex the carpus

Question 42

Deep digital flexor ORIGIN and INSERTION

Answer 42

O-humerus medial epicondyle, proximal/caudal border of ulna, medial border of radius I-Flexor tubercle on palmar surface of distal phalanx of each digits

Question 43

Deep digital flexor ACTION

Answer 43

Flex carpal and metacarpophalangeal joints and the proximal and distal interphalangeal joints of the dgits.