Muscles of the Thoracic Limb Flashcards
Which major flexor of the cubital (humeroradioulnar/elbow) joint is located on the medial aspect of the brachium?
The biceps brachii muscle is located on the medial aspect of the brachium.
Why does the ulnaris lateralis muscle flex the carpus despite its origin on the extensor surface of the humerus?
The ulnaris lateralis muscle flexes the carpus due to its caudal insertion point.
What structure is located within the brachialis groove of the humerus?
The brachialis muscle is located within the brachialis groove of the humerus.
What is the insertion of the trapezius muscle?
The trapezius muscle inserts at the spine of the scapula.
What major flexors of the humeroradioulnar (cubital/elbow) joint share a common insertion into the radial tuberosity and ulnar tuberosity?
The brachialis muscle has a common insertion with the biceps brachii muscle, as both of these muscles are the major flexors of the elbow (humeroradioulnar/cubital) joint.
What is the insertion of the omotransversarius muscle?
The omotransversarius muscle inserts at the distal end of the spine of the scapula.
What is the insertion of the cleidomastoideus muscle?
The cleidomastoideus muscle inserts at the mastoid part of the temporal bone.
Where does the medial head of the triceps brachii muscle originate?
The medial head of the triceps brachii muscle originates from the tricipital line and the proximal humerus.
What is the action of the superficial digital flexor muscle?
The superficial digital flexor muscle flexes digits II, III, IV, and V.
Where is the aponeurosis of the deep pectoral muscle?
The deep pectoral muscle has an aponeurosis extending into the axillary region and then converging with the medial fascia of the brachium.
What is the action of the ulnaris lateralis muscle?
The ulnaris lateralis muscle abducts the carpus and flexes the carpus.
What muscles form the boundaries of the jugular groove?
The brachiocephalicus muscle forms the dorsal boundary of the jugular groove. The ventral border of the jugular groove is the sternocephalicus muscle.
Where does the teres minor muscle insert?
The teres minor muscle inserts into the teres minor tuberosity of the humerus.
Where does the deltoideus muscle insert?
The deltoideus muscle inserts into the deltoid tuberosity of the humerus.
Where does the extensor carpi radialis muscle insert in the dog?
In dogs, the extensor carpi radialis muscle inserts into the dorsal aspect of the metacarpal tuberosities of metacarpals II and III.
What is the insertion of the biceps brachii muscle?
The biceps brachii muscle inserts into the radial tuberosity and the ulnar tuberosity.
What is the origin of the cleidocervicalis muscle?
The cleidocervicalis muscle originates from the clavicular intersection.
What is the origin of the brachialis muscle?
The brachialis muscle originates from the brachialis groove on the proximal and lateral aspect of the humerus.
What tendon is held in place by the transverse humeral retinaculum?
The transverse humeral retinaculum extends from the freater tubercle of the humerus to the lessertubercle of the humerus over the intertubercular groove, thereby holding the tendon of origin of the biceps brachii muscle in place.
The superficial cervical lymph node (prescapular lymph node) is located just cranial to the scapula and at the ventral border of which muscle?
The superficial cervical lymph node (prescapular lymph node) is located just cranial to the scapula and at the ventral border of the omotransversarius muscle.
What is the action of the triceps brachii muscle?
The triceps brachii muscle is essential for weight-bearing, as it maintains extension of the cubital (humeroradioulnar/elbow) joint. All heads of the triceps of brachii muscle extend the cubital (humeroradioulnar/elbow) joint, and the long head of the triceps brachii muscle flexes the glenohumeral (shoulder) joint.
What is the origin of the deltoideus muscle?
The deltoideus muscle originates from the spine of the scapula and the acromion of the scapula.
What is the action of the anconeus muscle?
The anconeus muscle extends the cubital (humeroradioulnar/elbow) joint.
What muscle of the glenohumeral (shoulder) joint has a long tendon of origin that is surrounded by a synovial sheath?
The tendon of origin of the coracobrachialis muscle is quite long and is surrounded by a synovial sheath.
What is the action of the long abductor muscle of the first digit?
The long abductor muscle of the first digit abducts digit I.
Where does the ulnaris lateralis muscle insert?
The ulnaris lateralis muscle inserts in the lateral aspect of the proximal end (base) of metacarpal V and the accessory carpal bone.
Which flexor of the carpus originates on the lateral epicondyle of the humerus?
The ulnaris lateralis muscle originates at the lateral epicondyle of the humerus.
What is the action of the deltoideus muscle?
The deltoideus muscle flexes the glenohumeral (shoulder) joint).
What is the action of the abductor pollicis longus muscle?
The abductor pollicis longus muscle abducts digit I.
What is the insertion of the rhomboideus muscle?
The rhomboideus muscle inserts at the dorsal border of the scapula.
What is the insertion of the brachiocephalicus muscle?
The brachiocephalicus muscle inserts at the distal end of the cranial humerus, the middorsal fibrous raphe of the neck, and the mastoid part of the temporal bone.
What is the action of the supinator muscle?
The supinator muscle rotates the antebrachium laterally so that the palmar surface of the paw faces medially (supination).
What is the action of the pronator teres muscle?
The pronator teres muscle rotates the antebrachium medially so that the palmar surface of the paw faces the ground (pronation).
What is the origin of the coracobrachialis muscle?
The coracobrachialis muscle originates from the coracoid process of the scapula.
What are the parts of the brachiocephalicus muscle?
The brachiocephalicus muscle has two parts:
Cleidobrachialis muscle part of the brachiocephalicus muscle
Cleidocephalicus muscle part of the brachiocephalicus muscle
Which muscle of the thoracic limb is the only flexor innervated by the radial nerve?
The ulnaris lateralis retains radial nerve innervation, which makes it the only flexor innervated by the radial nerve.
Where does the superficial pectoral muscle insert?
The superficial pectoral muscle inserts at the crest of the greater tubercle of the humerus.
What is the insertion of the cleidocephalicus muscle?
The cleidocephalicus muscle inserts at the middorsal fibrous raphe of the neck and the mastoid part of the temporal bone.
What is the origin of the trapezius muscle?
The trapezius muscle originates at the median fibrous raphe of the neck and the supraspinous ligament.
What is the long tendinous structure, prominant in horses, extending from the biceps brachii muscle to the extensor carpi radialis muscle?
The lacertus fibrosis, or the long tendon of the biceps brachii muscle, is a tendinous structure that is prominant in horses, but also present in weaker ruminants, that extends from the biceps brachii muscle to the extensor carpi radialis muscle.
What is the origin of the flexor carpi radialis muscle?
The flexor carpi radialis muscle originates from the medial epicondyle of the humerus and the medial border of the radius.
Where does the long abductor muscle of the first digit insert?
The long abductor muscle of the first digit inserts at the proximal end of metacarpal I.
What is the accessory ligament of the deep digital flexor muscle in the horse?
In the horse, the accessory ligament of the deep digital flexor muscle is known as the distal check ligament.
Where does the rhomboideus thoracis muscle originate?
The rhomboideus thoracis muscle originates from the spinous processes of the thoracic vertebrae.
Where does the lateral head of the triceps brachii muscle insert?
The lateral head of the triceps brachii muscle inserts into the olecranon of the cubital (humeroradioulnar/elbow) joint.
What is the action of the tensor fasciae antebrachii muscle?
The tensor fasciae antebrachii muscle extends the humeroradioulnar (cubital/elbow) joint.
What is the insertion of the lateral digital extensor muscle?
The lateral digital extensor muscle inserts into the extensor processes of distal phalanges III, IV, and V.
What are the specific parts of the cleidocephalicus muscle in equine species?
The cleidocephalicus muscle has one part in the horse:
Cleidomastoideus muscle part of the cleidocephalicus muscle
Which muscle’s tendon of origin passes through the greater and lesser tubercles within the intertubercular groove of the humerus?
The tendon of origin of the biceps brachii muscle passes through the greater and lesser tubercles within the intertubercular groove of the humerus.
Where does the serratus ventralis muscle originate?
The serratus ventralis muscle originates from the ribs and the transverse processes of the cervical vertebrae.
What are the heads of the triceps brachii muscle in the dog?
The dog has four heads of the triceps brachii muscle:
Long head of the triceps brachii muscle
Lateral head of the triceps brachii muscle
Medial head of the triceps brachii muscle
Accessory head of the triceps brachii muscle
What is the purpose of the annular ligaments?
The annular ligaments hold down the tendons of the superficial digital flexor muscle and the deep digital flexor muscle.
What are the heads of the flexor carpi ulnaris muscle?
The flexor carpi ulnaris muscle is made up of the ulnar head of flexor carpi ulnaris muscle and the humeral head of the flexor carpi ulnaris muscle.
What is another name for the interosseus muscle in the horse?
In the horse, there is one interosseus muscle and it is entirely tendinous and is commonly called the suspensory ligament.
What is the action of the brachiocephalicus muscle?
The brachiocephalicus muscle advances the limb, extends the glenohumeral (shoulder) joint, and draws the head and neck to the side.
What is the action of the superficial pectoral muscle?
The superficial pectoral muscle adducts the thoracic limb while the animal is not bearing weight on the limb and prevents abduction of the limb while the animal is bearing weight on the limb.
Where does the accessory head of the triceps brachii muscle originate?
The accessory head of the triceps brachii muscle originates from the tricipital line and the proximal humerus.
What is the action of the omotransversarius muscle?
The omotransversarius muscle advances the limb and flexes the neck laterally.
Where do all of the flexor muscles of the carpus and digits originate from?
All but one (ulnaris lateralis muscle) of the flexor muscles of the carpus and digits originate from the medial epicondyle of the humerus.
Which muscle will be encountered when surgically approaching the cubital (humeroradioulnar/elbow) joint?
The anconeus muscle will be encountered when surgically approaching the cubital (humeroradioulnar/elbow) joint.
Where does the accessory head of the triceps brachii muscle insert?
The accessory head of the triceps brachii muscle inserts into the olecranon of the cubital (humeroradioulnar/elbow) joint.
What is the action of the long head of the triceps brachii muscle?
The long head of the triceps brachii muscle flexes the glenohumeral (shoulder) joint and extends the cubital (humeroradioulnar/elbow) joint.
What is the origin of the teres major muscle?
The teres major muscle originates from the caudal angle of the scapula, the caudal border of the scapula, and the subscapularis muscle.
Where does the brachialis muscle insert?
The brachialis muscle inserts into the radial tuberosity and ulnar tuberosity.
What is the origin of the cleidobrachialis muscle?
The cleidobrachialis muscle originates from the clavicular intersection.
What is a fibrous raphe?
A fibrous raphe refers to the fusion of connective tissue structures at the midline of the animal.
What are the parts of the deltoideus muscle in the horse?
The deltoideus muscle is not divided in the horse, as the horse lacks an acromion. Therefore, there there is no acromial vs. scapular parts of the deltoideus muscle in the horse.
What is the insertion of the common digital extensor muscle in the dog?
The common digital extensor inserts into the extensor processes of distal phalanges II, III, IV, and V.
What is the action of the subscapularis muscle?
The subscapularis muscle medially stabilizes the glenohumeral (shoulder) joint by preventing lateral rotation while weight-bearing, adducts the glenohumeral (shoulder) joint, and extends the glenohumeral (shoulder) joint.
What is the action of the extensor carpi radialis muscle?
The extensor carpi radialis muscle extends the carpus.
What is the insertion of the rhomboideus thoracis muscle?
The rhomboideus thoracis muscle inserts at the dorsal border of the scapula.
What is the insertion of the teres major muscle?
The teres major muscle inserts at the teres major tuberosity of the humerus.
What is the action of the common digital extensor muscle?
The common digital extensor extends the joints of the four principal digits (digits II, III, IV, and V).
Where do all but one extensor muscles of the carpus and digits originate from?
All of the extensor muscles of the carpus and digits, except the extensor carpi radialis, originate from the lateral epicondyle of the humerus.
What is the action of the brachialis muscle?
The brachialis muscle is one of the major flexors of the elbow.
What is the origin of the infraspinatus muscle?
The infraspinatus muscle originates from the infraspinous fossa of the scapula.
What is the origin of the latissimus dorsi muscle?
The latissimus dorsi muscle originates from the thoracolumbar fascia and the last few ribs.
What is the action of the medial head of the triceps brachii muscle?
The medial head of the triceps brachii muscle extends the cubital (humeroradioulnar/elbow) joint.
Where does the superficial pectoral muscle originate?
The superficial pectoral muscle originates from the first three sternebrae and the median fibrous raphe at the ventral midline.
What is the origin of the supinator muscle?
The supinator muscle originates at the lateral epicondyle of the humerus.
What are the parts of the rhomboideus muscle?
The rhomboideus muscle has three parts: Rhomboideus capitis muscle Rhomboideus cervicis muscle Rhomboideus thoracis muscle
What is the origin of the anconeus muscle?
The anconeus muscle originates from the supracondylar crest of the humerus, the lateral epicondyle of the humerus, and the medial epicondyle of the humerus.
What is the insertion of the cleidobrachialis muscle?
The cleidobrachialis muscle inserts at the distal end of the cranial humerus.
What condition is seen in the horse in the image? What causes this condition?
The horse in the picture has a “flying scapula”, which can result from damage or loss of innervation, leading to myopathy of the serratus ventralis muscle.
