Thoracic_Limb_Muscle_Attachments_and_Functions Flashcards
superficial pectoral
Origin:
first three sternebrae
median fibrous raphe at the ventral midline
Insertion:
Humerus - greater tubercle (whole crest)
Action:
not weight bearing- adduct limb
weight bearing - prevent abduction
deep pectoral
Origin:
ventral part of sternum
median fibrous raphe at the ventral midline
Insertion:
lesser tubercle of the humerus (major portion of insertion)
greater tubercle and crest via aponeurosis
Action:
pull trunk cranially when limb is advanced and fixed
extend shoulder draw limb caudally when not supporting weight
brachiocephalicus
Origin:
clavicular intersection
Insertion:
distal end of cranial aspect of the humerus middorsal fibrous raphe of the neck mastoid part of the temporal bone
Action:
advance the limb extend shoulder draw head and neck to the side-
omotransversarius
Origin:
wing or transverse process of the atlas (cervical vertebra 1)
Insertion:
distal end of the spine of the scapula
Action:
advance the limb flex the neck laterally-
trapezius
Origin:
median fibrous raphe of the neck supraspinous ligament
Insertion:
spine of the scapula
Action:
elevate and abduct limb at the shoulder-
rhomboideus
Origin:
base of skull (nuchal crest of occipital bone) median fibrous raphe of neck spinous process of thoracic vertebrae
Insertion:
dorsal border of scapula
Action:
elevate limb draw scapula against trunk-
latissimus dorsi
Origin:
thoracolumbar fascia last 2 - 3 ribs
Insertion:
teres major tuberosity of the humerus via the teres major tendon
Action:
draw limb caudally (eg digging) flex shoulder-
serratus ventralis
Origin:
ribs transverse processes of cervical vertebrae
Insertion:
-serrated face of the scapula-
Action:
support trunk depress scapula-
deltoideus
Origin:
spine and acromial process of the scapula
Insertion:
deltoid tuberosity of the humerus
Action:
flex shoulder-
infraspinatus
Origin:
infraspinous fossa of the scapula
Insertion:
lateral side of the greater tubercule of the humerus (small circumscribed area)
Action:
laterally stabilizes the shoulder (prevents medial rotation while weight-bearing) abduct and laterally rotate shoulder assists other muscles in the extension or flexion of shoulder-
teres minor
infraglenoid tubercle of the scapula distal caudal border of the scapula -teres minor tuberosity of the humerus-laterally stabilizes the shoulder (prevents medial rotation while weight-bearing) laterally rotate shoulder flex shoulder (assists other muscles) –
supraspinatus
supraspinous fossa of the scapula-greater tubercle of the humerus (thick tendon)-laterally stabilizes the shoulder (prevents medial rotation while weight-bearing) extend shoulder-
subscapularis
subscapular fossa of the scapula-lesser tubercle of the humerus-medially stabilizes the shoulder (prevents lateral rotation while weight-bearing) adduct shoulder extend shoulder-
teres major
caudal angle and caudal border of the scapula subscapularis muscle-teres major tuberosity of the humerus-flex shoulder rotate arm medially-
coracobrachialis
coracoid process of the scapula-crest of the lesser tubercle of the humerus near the teres major tuberosity-mainly a shoulder stabilizer but can assist other muscles in adduction and/or extension of the shoulder-
tensor fasciae antebrachii
fascia covering the lateral surface of the latissimus dorsi muscle-olecranon of the ulna in common with the tendon of insertion of the triceps brachii muscle-extend elbow-
triceps brachii
caudal border of scapula (long head) tricipital line proximal humerus (neck lesser tubercle and crest of the lesser tubercle)-olecranon of ulna-flex shoulder (long head) extend elbow (all heads)-
anconeus
lateral supracondylar crest of the humerus lateral and medial epicondyles of the humerus-proximal and lateral aspect of the ulna-extend elbow-
biceps brachii
supraglenoid tubercle of the scapula-radial and ulnar tuberosities-extend shoulder flex elbow-
brachialis
proximal and lateral aspect of the humerus-radial and ulnar tuberosities-flex elbow-
extensor carpi radialis
lateral supracondylar crest of the humerus-metacarpal tuberosities (dorsal aspect) of MC II and III-extend carpus-
common digital extensor
lateral epicondyle of the humerus-extensor processes of the distal phalanx of digits II III IV and V-extend the joints of the four principal digits-
lateral digital extensor
lateral epicondyle of the humerus-extensor processes of the distal phalanx of digits III IV and V proximal ends of all phalanges of same digits-extend the joints of digits III IV and V-
ulnaris lateralis
lateral epicondyle of the humerus-lateral aspect of the proximal end of MC V accessory carpal bone-abduct carpus flex carpus-
supinator
lateral epicondyle of the humerus-cranial aspect of proximal radius-supination (rotate antebrachium laterally so that the palmar surface of the paw faces medially)-
pronator teres
medial epicondyle of the humerus-medial border of the radius-pronation (rotate the antebrachium medially so that the palmar surface of the paw faces the ground)-
abductor pollicis longus
lateral and cranial border of the ulna interosseus membrane between the radius and ulna-proximal end of metacarpal I-abduct digit I-
flexor carpi radialis
medial epicondyle of the humerus medial border of the radius-palmar surface of proximal MC II and III-flex carpus-
superficial digital flexor
medial epicondyle of the humerus-palmar surface of the base of the middle phalanges of digits II III IV and V-flex digits II - V –
flexor carpi ulnaris
medial epicondyle of the humerus caudal and medial aspect of olecranon-accessory carpal bone-flex carpus-
deep digital flexor
medial epicondyle of humerus ulna radius-flexor tubercle (palmar surface of the base) of the distal phalanx of each digit-flex digits-
