Forelimb Muscle Origins, Insertions & Functions Flashcards
what extend onto the leg to form the deep fasciae of the forelimb?
the deep fascia of the neck and of the trunk
what is the deep fascia on the medial surface of the shoulder called?
axillary fascia (fascia axillaris)
what is the distal continuation of the axillary fascia on the lateral surface of the brachium called?
the brachial fascia (fascia brachii)
what is the fascia that covers the extensor and flexor muscles of the elbow and digit in the forearm region called?
the antebrachial fascia (fascia antebrachii)
what does the dorsal deep fascia contribute to?
the extensor retinaculum
what does the palmar deep fascia contribute to?
the flexor retinaculum
what does the palmar deep fascia form in horses?
the anular ligament of the fetlock and other supportive structure of the fetlock
what does the superficial layer of extrinsic forelimb musculature comprise? (5)
m. trapezius, m. sternocleidomastoideus, m. omotransversarius, m. latissimus dorsi, m. pectoralis superficialis
what muscles make up m. sternocleidomastoideus?
sternocephalic and brachiocephalic muscle
what portions does m. trapezius consist of?
a cervical and thoracic portion divided by a tendinous band
what is the shape of m. trapezius?
broad, thin, triangular
where does the cervical portion of m. trapezius originate?
the caudal half of dorsal raphe of the neck
where does the cervical portion of m. trapezius insert?
proximal 4/5 of scapular spine
where does the thoracic portion of m. trapezius originate?
the supraspinous ligaments and the dorsal spinous processes (3rd c.v to 9th t.v)
where does m. trapezius insert?
proximal 1/3 of scapular spine
what is the function of m. trapezius?
caudal rotation of scapula
where does m. sternocephalicus extend between?
the sternum and the head
where does m. brachiocephalicus extend between?
the humerus and the head
what is the function of brachiocephalicus?
main protractor of forelimb
what can the brachiocephalic muscle be subdivided into?
cleidobrachialis, cleidocervicalis, cleidomastoideus
where do the 3 muscles of brachiocephalicus interconnect?
at the clavicular tendon
where does the cleidobrachial muscle originate?
the clavicular tendon
where does the cleidobrachial muscle insert?
cranially on distal 3rd of humerus shaft
what is the cleidocephalic muscle (cleidocervicalis) between?
origin= cranial half of median raphe of neck, insertion= the clavicular tendon
what are the 2 portions of the sternocephalic muscle in carnivores?
m. sternomastoideus and m. sterno-occipitalis
where do both m. sternomastoideus and m. sterno-occipitalis originate?
the manubrium of the sternum
where do both m. sternomastoideus and m. sterno-occipitalis insert?
the mastoid process of the temporal bone and nuchal crest of the occipital bone respectively
what are the 2 parts of m. sternocephalicus in the ox and goat?
m. sternomastoideus and m. sternomandibularis
where does the sternomandibular muscle originate in the ox/goat?
the manubrium of the sternum and the 1st rib
where does m. sternomandibularis insert in the ox/goat?
the mandible by means of an aponeurosis
what is m. sternocephalicus called in the pig?
m sterno-occipitalis
where does the sternomandibular muscle originate in the horse?
from the manubrium of the sternum
where does the sternomandibular muscle insert in the horse?
with a thin tendon to the mandible
where does the cleidomastoid muscle originate?
midline of the neck
where does cleidomastoideus insert?
clavicular tendon
what is the shape of m. omotransversarius?
strong, cord-like muscle
where does omotransversarius originate?
the wing of the atlas
where does omotransversarius insert?
distal 1/5 of scapular spine
what is the ventral border of m. omotransversarius fused to?
the cervical part of the trapezius muscle
what does m. omotransversarius unite with in the horse?
the cleidomastoid muscle
what is the function of omotransversarius?
caudal rotation of scapula
what is the function of the sternocephalic muscle?
flexor of the head and neck
what is the insertion of m. latissimus dorsi?
teres tuberosity of humerus
what is the origin of latissimus dorsi?
spinous processes of trunk vertebrae (T7-L7), caudal 2 or 3 ribs
what is the function of latissimus dorsi?
prime retractor of forelimb
what direction are the fibres of m. latissimus dorsi?
cranioventral
what are the additional attachment of m. latissimus dorsi in carnivores? (5)
the last thoracic vertebrae, the lumbar vertebrae, the ribs, branch to the deep pectoral muscle, blends with the tendon of the teres major muscle
what is the additional origin of m. latissimus dorsi in the horse?
the supraspinous ligament of the thoracic and lumbar vertebrae
where does m. latissimus dorsi insert in the horse?
with the tensor muscle of the antebrachial fascia and the teres major muscle on the medial aspect of the proximal humerus
what muscles occupy the space between the ventral part of the thoracic wall and the proximal part of the thoracic limb?
the superficial pectoral muscles
what do the superficial pectoral muscles comprise?
the descending (m. pectoralis descendens) and the transverse pectoral muscle (m. pectoralis transversus)
where do the superficial pectoral muscles originate
sternebrae 1-3
where do the superficial pectoral muscles insert?
cranially on distal 2/3 of humerus shaft
in which species are the 2 parts of the superficial pectoral muscles hardly discernable?
carnivores
what is the function of the superficial pectoral muscles?
adductor
where does the transverse pectoral muscle originate in the horse?
the 1st 6 costal cartilages and the sternum
what does the deep layer of the extrinsic musculature of the forelimb comprise? (3)
deep pectoral muscle; m. rhomboideus; m. serratus ventralis
where does the deep pectoral muscle originate?
from the sternum
where does the deep pectoral muscle insert?
lesser tuberosity of humerus with tendinous slips to greater tuberosity
what is the function of the deep pectoral muscle?
adductor
what are the two parts of rhomboideus?
cervical and thoracic
where does cervical rhomboid originate?
dorsal median raphe of neck C2-T3 and nuchal crest
where does cervical rhomboid insert?
cranial angle and vertebral border of scapula
what is the function of rhomboideus?
elevates scapula
where does the thoracic rhomboid originate?
dorsal median raphe of thorax T4-T7
where does the thoracic rhomboid insert?
caudal angle and vertebral border of scapula
what are the two parts of serratus ventralis?
cervical and thoracic
where does cervical serratus ventralis originate?
neck vertebrae (C3-C7) costo-transverse processes
where does cervical serratus ventralis insert?
cranial serrated area of scapula
what is the function of cervical serratus ventralis?
cranial rotator of scapula, opposes action of trapezii
what is the function of thoracic serratus ventralis?
depressor of limb
where does thoracic serratus ventralis originate?
individual slips from ribs 1-8
where does thoracic serratus ventralis insert?
caudally serrated area of scapula
what are the lateral shoulder muscles? (4)
supraspinatus, infraspinatus, teres minor, deltoidei
what is the origin of supraspinatus?
supraspinous fossa
what is the insertion of supraspinatus?
summit of greater tuberosity
what is the function of supraspinatus?
shoulder extensor
what is the origin of infraspinatus?
infraspinous fossa
what is the insertion of infraspinatus?
laterally on greater tuberosity
what inserts on the greater tuberosity?
what is the function of infraspinatus?
stabilise shoulder joint against adduction
what are the two parts of deltoideus?
spinodeltoideus and acromiodeltoideus
what is the function of the deltoidei?
shoulder flexor
what is the origin of spinodeltoideus?
scapular spine
what is the origin of acromiodeltoideus?
acromion
where do the deltoidei insert?
deltoid tuberosity on lateral humerus
where does teres minor originate?
the distal third of the caudal border
where does teres minor insert?
teres tuberosity
what is the function of teres minor?
shoulder flexor
what are the medial shoulder muscles?
teres major, subscapularis,
what is the origin of teres major?
caudal border of scapula
what is the insertion of teres minor?
teres tuberosity
what is the function of teres major?
shoulder flexor
what is the origin of subscapularis?
subscapular fossa
what is the insertion of subscapularis?
lesser tuberosity
what is the function of subscapularis?
mainly shoulder extensor, can contribute to maintaining shoulder flexion
where does tensor fasciae antebrachii originate?
lateral side of latissimus dorsi
where does tensor fasciae antebrachii insert?
antebrachial fascia and olecranon
what is the function of tensor fasciae antebrachii?
elbow extensor
what are the muscles of the elbow joint?
brachialis, triceps, biceps, anconeus, tensor fasciae antebrachii
how many heads does triceps have in dog?
4
how many heads does triceps have in species other than dogs?
3
what is the extra triceps head that dogs have?
accessory head
what are the 3 heads of triceps in all species?
long, lateral, medial
what are the 4 heads of triceps in dogs?
long, lateral, medial, accessory
what is the origin of the lateral head of triceps?
deltoid crest of humerus
what is the origin of the medial head of triceps?
lesser tuberosity of humerus
what is the origin of the long head of triceps?
caudal border of scapula
what is the origin of the accessory head of triceps?
neck of humerus
what is the insertion of triceps?
olecranon process of ulna
what is the function of triceps?
elbow extensor
how many heads does biceps have in dog?
one
what is the origin of biceps?
bicipital process of scapula
what is the main insertion of biceps in the dog?
ulnar tuberosity
what is the main insertion of biceps in the cat?
radius
what is the function of biceps?
elbow flexor and in cats prime supinator of elbow
what binds the tendon of origin of biceps in the bicipital groove?
transverse humeral ligament
where is the bicipital bursa?
deep to tendon of origin
what is the origin of brachialis?
proximally in musculospiral groove
what is the insertion of brachialis?
ulnar tuberosity of ulna
what is the function of brachialis?
elbow flexor
what are the supinators of the forearm?
brachioradialis and supinator muscle
what are the pronators of the forearm?
pronator teres and pronator quadratus
in what animals is the supinator muscle present?
carnivores and pigs
in what animals is pronator teres present?
carnivores, inconsistently present in pigs, ruminants and horse
in what animals is pronator quadratus present?
carnivores
what are the muscles of the carpus?
extensor carpi radialis, extensor carpi ulnaris, flexor carpi radialis, flexor carpi ulnaris, extensor carpi obliquus
where are the extensor muscles of the carpus and digits?
the cranio(dorso)lateral side
where are the flexor muscles of the carpus and digits?
the caudo (palmar) side
what is the origin of ECU?
lateral epicondyle
what is the insertion of ECU?
laterally, proximally on MC5
what is ECU called in ungulates?
ulnaris lateralis
what is the function of ECU in carnivores?
helps extend the carpus or flex the carpus when carpus is already extended or flexed, abducts the forearm
what is the function of ECU in species other than carnivores?
flexes the carpus
what is the origin of ECR?
lateral supraepicondylar ridge
what is the insertion of ECR?
tubercles proximally on MC 2 and 3
what is the function of ECR?
extends carpus and flexes elbow
what is the origin of ECO?
craniolateral on middle 1/2 of ulna
what is the insertion of ECO?
proximal MC1
what is the origin of FCU?
medial epicondyle (fleshy), medially on olecranon of ulna (fibrous)
what are the 2 straps of FCU?
fleshy and fibrous
what is the insertion of FCU?
proximal on palmar aspect of MC 4 and 5 via accessory carpal bone
what is the function of FCU?
flexes carpus, in carnivores is supinator of limb
what is the origin of FCR?
medial epicondyle, medial radial shaft
what is the insertion of FCR?
proximal on palmar aspect of MC 2 and 3
what is the order of the flexors FCR, FCU and SDF from medial to lateral?
FCR, SDF, FCU
what is the origin of pronator teres?
medial epicondyle
what is the insertion of pronator teres?
proximally on radius just above oblique line
what is the origin of brachioradialis?
lateral supra-epicondylar ridge
what is the insertion of brachioradialis?
medially on distal radius
what is the origin of pronator quadratus?
interosseus edge of radius
what is the insertion of pronator quadratus?
interosseus edge of ulna
where are the extensor muscles of the digits located?
on the cranio(dorso)lateral side of the antebrachium
where are the flexor muscles of the digits located?
on the caudal (palmar) side of the antebrachium
where do the common and lateral digital extensors originate from?
the lateral epicondyle of the humerus
where do the digital flexors originate from?
the medial epicondyle of the humerus
what are the digital extensors?
common digital extensor, lateral digital extensor, long abductor muscle of the first digit, extensor of digits 1 and 2
what is the insertion of CDE?
extensor process of distal phalanx of digits 2-5
what is the function of CDE?
extends the carpal and digital joints
what is the insertion of LDE?
proximally on all phalanges of digits 3-5
what is the function of LDE in carnivores and the pig?
extends the carpal and phalangeal joints of the lateral digits
what is the function of LDE in ruminants?
extends the carpus, fetlock and pastern joints
what is the function of LDE in horses?
extends the carpus and fetlock joint
what is the insertion of the long abductor of the first digit in carnivores?
first metacarpal bone
what is the origin of the long abductor of the first digit?
middle 1/3 of the lateral border of the radius and ulna
what is the function of the long abductor of the first digit?
extends the carpus and digit to which it extends, abductor of first digit in carnivores
what is the insertion of the long abductor of the first digit in pigs and horses?
second metacarpal bone
what is the insertion of the long abductor of the first digit in ruminants?
third metacarpal bone
what is the origin of the extensor of digits 1 and 2?
craniolateral on middle 1/3 of ulna
what is the insertion of the extensor of digits 1 and 2?
distal MC 1, proximally on all phalanges of digit 2
what is the function of the extensor of digits 1 and 2?
prevents abduction of digit 1
what is the origin of SDF?
medial epicondyle
what is the insertion of SDF?
proximal on the 2 palmar tubercles of phalanx 2 of digit 5
what is the origin of interosseus? (dog)
proximal end of palmar surface of MC 2-5
what are the insertions of interosseus? (dog)
paired tubercles on proximal end of phalanx 1 of digits 2-5, via tendinous slips that pass around digits to extensor tendons of same digits
how many interossei do dogs have?
one for each digit
what sort of muscle is teres minor?
capsular muscle
what is the function of teres minor?
to prevent capsule from becoming trapped between scapula and humerus
what is the origin of teres minor?
distally on caudal border of scapula
what is the insertion of teres minor?
greater tuberosity
what type of muscle is coracobrachialis?
capsular
what is the function of coracobrachialis?
to prevent capsule from becoming trapped between scapula and humerus
what is the origin of coracobrachialis?
coracoid process of scapula
what is the insertion of coracobrachialis?
line between lesser and teres tuberosities
what sort of muscle is anconeus?
capsular
what is the function of anconeus?
tenses the lateral side of the elbow joint capsule
what is the origin of anconeus?
caudally on lateral supra-epicondylar ridge
what is the insertion of anconeus?
laterally on olecranon
where does extensor carpi radialis insert in the horse?
on cannon bone
what is the interosseus called in the horse?
suspensory ligament
