TL Origins, Insertions and Actions Flashcards
Infraspinatus
Origin
infraspinous fossa of the scapula
Insertion
lateral side of the greater tubercule of the humerus
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
superficial pectoral
Origin
first three sternebrae; median fibrous raphe at the ventral midline
Insertion
whole crest of the greater tubercle of the humerus
Action
adduct limb when not bearing weight; prevention of abduction of limb while bearing weight
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 (e.g., 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
teres minor
Origin
infraglenoid tubercle of the scapula; distal caudal border of the scapula
Insertion
teres minor tuberosity of the humerus
Action
laterally stabilizes the shoulder (prevents medial rotation while weight-bearing); laterally rotate shoulder; flex shoulder (assists other muscles)
supraspinatus
Origin
supraspinous fossa of the scapula
Insertion
greater tubercle of the humerus (thick tendon)
Action
laterally stabilizes the shoulder (prevents medial rotation while weight-bearing); extend shoulder
subscapularis
Origin
subscapular fossa of the scapula
Insertion
lesser tubercle of the humerus
Action
medially stabilizes the shoulder (prevents lateral rotation while weight-bearing); adduct shoulder; extend shoulder
teres major
Origin
caudal angle and caudal border of the scapula; subscapularis muscle
Insertion
teres major tuberosity of the humerus
Action
flex shoulder; rotate arm medially
coracobrachialis
Origin
coracoid process of the scapula
Insertion
crest of the lesser tubercle of the humerus, near the teres major tuberosity
Action
mainly a shoulder stabilizer, but can assist other muscles in adduction and/or extension of the shoulder
triceps brachii
Origin
caudal border of scapula (long head); tricipital line, proximal humerus
Insertion
olecranon of ulna
Action
flex shoulder (long head); extend elbow (all heads)
anconeus
Origin
lateral supracondylar crest of the humerus; lateral and medial epicondyles of the humerus
Insertion
proximal and lateral aspect of the ulna
Action
extend elbow
biceps brachii
Origin
supraglenoid tubercle of the scapula
Insertion
radial and ulnar tuberosities
Action
extend shoulder; flex elbow
brachialis
Origin
proximal and lateral aspect of the humerus
Insertion
radial and ulnar tuberosities
Action
flex elbow
extensor carpi radialis
Origin
lateral supracondylar crest of the humerus
Insertion
metacarpal tuberosities (dorsal aspect) of MC II and III
Action
extend carpus
common digital extensor
Origin
lateral epicondyle of the humerus
Insertion
lateral epicondyle of the humerus extensor processes of the distal phalanx of digits II, III, IV, and V
Action
extend the joints of the four principal digits
lateral digital extensor
Origin
lateral epicondyle of the humerus
Insertion
extensor processes of the distal phalanx of digits III, IV, and V; proximal ends of all phalanges of same digits
Action
extend the joints of digits III, IV, and V
ulnaris lateralis
Origin
lateral epicondyle of the humerus
Insertion
lateral aspect of the proximal end of MC V; accessory carpal bone
Action
abduct carpus; flex carpus
supinator
Origin
lateral epicondyle of the humerus
Insertion
cranial aspect of proximal radius
Action
supination (rotate antebrachium laterally so that the palmar surface of the paw faces medially)
pronator teres
Origin
medial epicondyle of the humerus
Insertion
medial border of the radius
Action
pronation (rotate the antebrachium medially so that the palmar surface of the paw faces the ground)
abductor pollicis longus
Origin
lateral and cranial border of the ulna; interosseus membrane between the radius and ulna
Insertion
proximal end of metacarpal I
Action
abduct digit I
flexor carpi radialis
Origin
medial epicondyle of the humerus; medial border of the radius
Insertion
palmar surface of proximal MC II and III
Action
flex carpus
superficial digital flexor
Origin
medial epicondyle of the humerus
Insertion
palmar surface of the base of the middle phalanges of digits II, III, IV, and V
Action
flex digits II - V
flexor carpi ulnaris
Origin
medial epicondyle of the humerus; caudal and medial aspect of olecranon
Insertion
accessory carpal bone
Action
flex carpus
deep digital flexor
Origin
medial epicondyle of humerus; ulna; radius
Insertion
flexor tubercle (palmar surface of the base) of the distal phalanx of each digit
Action
flex digits
pronator quadratus
(action only)
Action
pronate the antebrachium
