Muscle origins, actions and insertions - Thoracic limb Flashcards
Superficial pectoral muscle
Origin: Sternum
Insertion: Greater tubercle & cranial hmeral border
Action: Adduct thoracic limb
Deep pectoral muscle
Origin: Sternum
Insertion: Greater and lesser tubercles
Action: Adduct thoracic limb and flex shoulder joint
Brachiocephalicus (Cleidobrachialis, Cleidocephalicus)
Origin: Clavicular Intersection
Insertion: Cleidobrachialis - distal cranial humerus
Cleidocephalicus :
pars mastoidea - mastoid process
pars cervicalis - dorsal mid-line of the neck
Action: Pull thoracic limb cranially, dpress head pull head and neck laterally
Sternocephalicus
Origin: Sternum
Insertion: Mastoid part of temporal bone, occipital bone
Action: Depress head, Draw the head and neck to the side
Sternohyoideus
Origin: Sternum
Insertion: Basihyoid bone
Action: Pull the tongue and larynx caudally
Sternothyroideus
Origin: Cranial aspect of sternum (manubrium)
Insertion: thyroid cartilage
Action: Draw the tongue and larynx caudally
Omotransversarius
Origin: wing of the atlas
Insertion: distal spine of scapula
Action: Pull limb cranially or flex the neck laterally
What is the supraspinous ligament?
Connects dorsal aspects of vertebral spines
What is the nuchal ligament?
Extends from the spine of the first thoracic to the spine of the axis
Trapezius
Origin: Dorsal neck (cervical) Dorsal thoracic (thoracic)
Insertion: Spine of the scapula
Action: Elevate the forelimb
Rhomboideus
Origin:
Capitis - Nuchal crest
Cervicis - Dorsal neck
Thoracis - Dorsal thorax
Insertion: Dorsal border of scapula
Action: Elevate the forelimb
Latissimus dorsi
Origin: thoracolumbar fascia
Insertion: Teres major tuberosity
Action: Draw the limb caudally, flex or extend the humeral joint
Serratus ventralis (cervicis, thoracis)
Origin:
Cervicis - cervical vertebrae
Thoracis - thoracic wall (ribs)
Insertion: Serrated face of scapula
Action: Support/elevate the trunk
Deltoideus
Origin: The spine of the scapula and acromion
Insertion: Deltoid tuberosity
Action: Flex the humeral joint
Infraspinatus
Origin: Infraspinous fossa
Insertion: greater tubercle
Action: Flex humeral joint, abduct limb at humeral joint, lateral collateral ligament for scapula
Teres minor (ID only)
Origin: caudal border of the scapula
Insertion: Teres minor tuberosity
Action: Flex shoulder joint, rotate shoulder laterally, prevent medial rotation when weight bearing
Supraspinatus
Origin: Supraspinous fossa
Insertion: Greater tubercle
Action: Extend humeral joint
Subscapularis
Origin: Subscapular fossa
Insertion: Lesser tubercle
Action: Adduct limb at humeral joint, medial collateral ligament
Teres major
Origin: caudal border of the scapula
Insertion: Teres major tuberosity
Action: Flex humeral joint
Coracobrachialis
Origin: Coracoid process of the scapula
Insertion: Crest of the lesser tubercle
Action: Stabilize humeral joint medially
Tensor fasciae antebrachii
Origin: Fascia covering the lateral side of the latissimus dorsi
Insertion: Olecranon
Action: Extends the elbow
Triceps brachii - long head
Origin: Caudal border of the scapula
Insertion: Olecranon tuber
Action: Extends the cubital joint, flex the humeral joint
Triceps brachii - lateral head
Origin: Proximal hmerus
Insertion: Olecranon tuber
Action: Extend the elbow
Triceps brachii - accessory head
Origin: Proximal humerus
Insertion: Olecranon tuber
Action: Extends the elbow
Triceps brachii - medial head
Origin: Proximal humerus
Insertion: Olecranon
Action: Extend the elbow
Aconeous (ID only)
Origin: Lateral suprachondylar crest
Insertion: olecranon tuber
Action: Extend the elbow
Biceps brachii
Origin: Supraglenoid tubercle
Insertion: Ulnar and radial tuberosities
Action: Flex the cbital joint, extend the humeral joint
Brachialis
Origin: Brachialis groove
Insertion: Proximal radius/ulna
Action: Flex the cubital joint
Extensor carpi radialis
Origin: Lateral epicondyle of humerus
Insertion: dorsal base of metacarpals II and III
Action: Extend the carpal joints
Common digital extensor
Origin: Lateral epicondyle of the humerus
Insertion: Extensor processes of distal phalanges
Action: Extend carpal and digital joints
Lateral digital extensor
Origin: Lateral epicondyle of humerus
Insertion: distal phalanges phalanges III, IV, and V
Action: Extend carpal and digital joints and digits III, IV, V
Ulnaris Lateralis
Origin: Lateral epicondyle of humerus
Insertion: accessory carpal bone and base of 5th metacarpal bone
Action: Flex carpal joints, abduct manus
Abductor digiti I longus (ID only)
Origin: Body of Ulna
Insertion: Proximal end of metacarpal I
Action: Abduct the first digit, extend carpal joints
Pronator teres
Origin: Medial epicondyle of humerus
Insertion: Medial border of radius
Action: Weak pronation of manus, weak flexion of cubital joint
Supinator (ID only)
Origin: Lateral epicondyle of humerus
Insertion: Body of radius
Action: Supination of manus
Flexor carpi radialis
Origin: Medial epicondyle of humerus
Insertion: Palmar base of metacarpals II and III
Action: Flex the carpal joints
Superficial digital flexor
Origin: medial epicondyle of humerus
Insertion: Middle phalanges of the digits
Action: Flex carpal joints, metacarpophalangeal and proximal interphalangeal joints
Flexor carpi ulnaris - both heads
Origin: Medial epicondyle and olecranon
Insertion: Accessory carpal bone
Action: Flex carpal joints
Deep digital flexor - Humeral head
Origin: Medial epicondyle of humerus
Insertion: Flexor tubercles of distal phalanges
Action: Flex the carpal and digital joints
Deep digital flexor - Ulnar head
Origin: caudal border of ulna
Insertion: Flexor tubercles of distal phalanges
Action: Flex the carpal and digital joints
Deep digital flexor - radial head
Origin: medial border of the radius
Insertion: Flexor tubercles on distal phalanges
Action: Flex the carpal and digital joints
Pronator quadratus
Origin and insertion: Apposed surfaces of the radius and ulna
Action: pronate the manus
Interossei
Origin: Palmar base of (respective) metacarpal
Insertion: Palmar base of (respective) proximal phalanx and tendon of common DE
Action: Flex and support metacarpophalangeal joint
Tensor fasiae antbrachii
Origin: Lattissimus dorsi and associated fascia
Insertion: Olecranon tuber
Action: Extend cubital joint and tense deep antebrachial fascia
Brachioradialis
Origin: Lateral epicondyle of the humerus
Insertion: fascia near the carpus
Action: Flex cubital joint, supinate the manus
