Thoracic Limb: Origin, Insertion, Action, Innervation Flashcards
Two superficial pectoral muscles with ORIGINS and INSERTIONS
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
ACTION of superficial pectoral muscles
ACTION: Adduct limb when it’s not bearing weight or prevent limb from being abducted when bearing weight.
Deep pectoral ORIGIN and INSERTION
O-Ventral part of sternum and fibrous part of raphe
I-Majority (tendinous) on lesser tubercle
Deep pectoral ACTION
Pull trunk cranially and extend shoulder joint (supporting wt). If not supporting wt, to abduct and flex shoulder jt.
Two muscles that make up the brachiocephalicus ORIGIN and INSERTION
1)Cleidobrachialis
O- clavicle
I-Distal end of cranial border of humerus
2)Cleidocephalicus
O-clavicle
I-Clavicular tendon to the neck and head
Two parts of cleidocephalicus
1-cleidocervicalis: attaches to mid-dorsal fibrous raphe and nuchal crest of occipital bone.
2-cleidomastoideus: attaches to mastoid process of temporal bone
Omotransversarius attachment
Distal end of spine of scapula and transverse wing of atlas
Omotransversarius ACTION
Advance limb or flex neck laterally
Two parts of tapezius muscle
1-Cervical: cranial to aponeurosis
2-Thoracic: caudal to aponeurosis
Trapezius ORIGIN and INSERTION
O-Median raphe of neck and supraspinous ligament from C3 to T9.
I-Spine of scapula
Three parts of the rhomboideus muscle
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.
Rhomboideus ORIGIN and INSERTION
O-Nuchal crest of occipital bone, median raphe of neck, spinous process of first 7 T vertebrae
I-dorsal border of scapula
Lastissimus dorsi ORIGIN and INSERTION
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
Rhomboideus ACTION
Elevate forelimb and draw scapula against trunk
Latissimus dorsi ACTION
Flex shoulder joint- create digging action.
Serratus ventralis cervicis and serratus ventralis thoracis ORIGIN and INSERTION
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
Trapezius action
To elevate and abduct the forelimb
Supraspinatus ORIGIN and INSERTION
O-supraspinous fossa
I-> tubercle of the humerus by a thick tendon
Supraspinatus ACTION
To extend and laterally stabilize the shoulder joint
Teres minor ORIGIN and INSERTION
O-Infraglenoid tubercle and distal 3rd of caudal border of spine
I-Teres minor tuberosity of humerus
Teres major ACTION
Flex the shoulder, rotate the shoulder laterally, and prevent medialrotation when weight bearing.
Name the four parts of the triceps brachii
1-Long head
2-Lateral head
3-Accessory head
4-Medial head
Triceps brachii- long head ORIGIN and INSERTION
O-Caudal border of scapula
I-Olecranon tuber
Triceps brachii-long head ACTION
Extend elbow and flex the shoulder
Triceps brachii-lateral head ORIGIN and INSERTION
O-Tricipital line of the humerus
I-Olecranon tuber
Tricpes brachii- lateral head ACTION
Extend elbow
Triceps brachii- accessory head ORIGIN and INSERTION
O-Neck of the humerus
I-Olecranon tuber
Triceps brachii-accessory head ACTION
Extend elbow
Triceps brachii- medial head ORIGIN and INSERTION
O-Crest of the lesser tubercle near the teres major tuberosity
I-Olecranon
Triceps brachii- medial head ACTION
Extend elbow
Brachiocephalicus ACTION
Advance limb, extend shoulder joint, and draw neck to the side.
Biceps brachii ORIGIN and INSERTION
O-Supraglenoid tubercle
I-The ulnar and radial tuberosties
Biceps brachii ACTION
Flex elbow and extend shoulder
Extensor carpi radialis ORIGIN and INSERTION
O-Lateral supracondylar crest
I-Small tuberosities on the dorsal surfaces of the base of metacarpals II and III.
Extensor carpi radialis ACTION
Extend carpus
Common digital extensor ORIGIN and INSERTION
O-Lateral epicondyle of humerus
I-Extensor processes of the distal phalanges of digits II,III,IV,V
Common digital extensor ACTION
Extend joints of the four principal digits (2-5) and the carpus
Superficial digital flexor ORIGIN and INSERTION
O-Medial epicondyle of the humerus
I-Palmar surface of the proximal end of middle phalanges of digits 2-5
Superficial digital flexor ACTION
Flex carpal, metacarpophalangeal, and proximal interphalangeal joints of digits 2-5.
Flexor carpi ulnaris: two parts ORIGIN and INSERTION
Ulnar head: caudal border/medial surface of olecranon
Humeral head:medal epicondyle of the humerus
Insertion-accessory carpal bone
Flexor carpi ulnaris ACTION
Flex the carpus
Deep digital flexor ORIGIN and INSERTION
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
Deep digital flexor ACTION
Flex carpal and metacarpophalangeal joints and the proximal and distal interphalangeal joints of the dgits.
