Anatomy Bootcamp Muscles - Origin, Action, Termination

What is the function of the thoracic limb?

attaches the limb to the axial skeleton

What are the extrinsic muscles of the thoracic limb?

superficial pectoral, deep pectoral, brachiocephalicus, omotransversarius, trapezius, rhomboideus, latissimus dorsi, and serratus ventralis

Superficial pectoral origin

Superficial pectoral originates on sternum

Superficial pectoral termination

Superficial pectoral terminates on greater tubercle of the humerus

Superficial pectoral action

The superficial pectoral adduct the thoracic limb

Deep pectoral origin

The deep pectoral originates on sternum

Deep pectoral termination

The deep pectoral terminates on greater and lesser tubercles of humerus

Deep pectoral action

The deep pectoral adducts thoracic limb and pulls caudally

Brachiocephalicus origin

The brachiocephalicus originates on the clavicular intersection

Brachiocephalicus termination

The brachiocephalicus terminates on the humerus, skull, and neck

Brachiocephalicus action

The brachoicephalicus pulls the thoracic limb cranially and/or depress and pulls the head and neck laterally

Omotransversarius origin

The omotransversarius originates on the wing of the atlas

Omotransversarius termination

The omotranversarius terminates on the distal spine of scapula

Omotransversarius action

The omotransversarius pulls thoracic limb cranially and/or depress and pulls the head and neck laterally

Trapezius origin in the cervical region

dorsal neck

Trapezius origin in thoracic region

dorsal thorax

Trapezius termination

The trapezius terminates on the spine of the scapula

Trapezius action

The trapezius elevates the thoracic limb

Rhomboideus termination

The rhomboideus terminates on the dorsal border of the scapula

Rhomboideus action

The rhomboideus elevates the thoracic limb

Serratus ventralis origin

The serratus ventralis originates on the cervical vertebrae and thoracic wall (ribs)

Serratus ventralis termination

The serratus ventralis terminates on the serrated face of the scapula

Serratus ventralis action

The serratus ventralis support and/ or elevates the trunk

Latissimus dorsi origin

The latissimus dorsi originates on the thoracolumbar fascia

Latissimus dorsi action

The latissimus dorsi draws the thoracic limb caudally; flex or extend the humeral joint

What are the muscles of the ventral neck?

Sternocephalicus, sternohyoideus, and sternothyroideus

Sternocephalicus origin

The sternocephalicus originates on the sternum

Sternocephalicus termination

The sternocephalicus terminates on the bones of the skull

Sternocephalicus action

The sternocephalicus depresses head and neck; draws head and neck laterally

Sternohyoideus origin

The sternohyoideus originates on the sternum

Sternohyoideus termination

The sternohyoideus terminates on the basihyoid bone

Sternohyoideus action

The sternohyoideus pulls tongue and larynx caudally

Sternothyroideus origin

The sternothyroideus originates on cranial aspect of sternum

Sternothyroideus termination

The sternothyoideus terminates on thyroid cartilage

Sternothyroideus action

The sternothyroideus pulls tongue and larynx caudally

What are the lateral muscles of the shoulder?

deltoideus, infraspinatus, teres minor, and supraspinatus

Deltoideus origin

The deltoideus originates on the spine of the scapula and acromion

Deltoideus termination

The deltoideus terminates on the deltoid tuberosity of humerus

Deltoideus action

The deltoideus flexes the humeral joint

Supraspinatus origin

The supraspinatus originates on the supraspinous fossa of the scapula

Supraspinatus termination

The supraspinatus terminates on the greater tubercle of the humerus

Supraspinatus action

The supraspinatus extends the humeral joint

Infraspinatus origin

The infraspinatus originates on the infraspinous fossa of the scapula

Infraspinatus termination

The infraspinatus terminates on the greater tubercle of the humerus

Infraspinatus action

The infraspinatus flexes the humeral joint; abducts the limb at the humeral joint

Teres minor origin

Teres minor originates on caudal border of scapula

Teres minor action

Teres minor flexes the humeral joint

What are the intrinsic medial muscles of the shoulder?

subscapularis, teres major, and coracobrachialis

Subscapularis origin

Subscapularis originates on subscapular fossa of scapula

Subscapularis termination

Subscapularis terminates on lesser tubercle of humerus

Subscapularis action

Subscapularis adducts limb at humeral joint

Teres major origin

Teres major originates on caudal border of scapula

Teres major action

Teres major flexes the humeral joint

Coracobrachialis origin

Coracobrachialis originates on coracoid process of the scapula

Coracobrachialis termination

Coracobrachialis terminates on lesser tubercle of the humerus

Coracobrachialis action

Coracobrachialis adducts limb at shoulder

What are the intrinsic cranial muscles of the brachium?

biceps brachii and brachialis

Biceps brachii origin

Biceps brachii originates on supraglenoid tubercle

Biceps brachii action

Biceps brachii extend the humeral joint and flexes cubital joint

Brachialis origin

Brachialis originates on brachial groove of humerus

Brachialis action

Brachialis flexes the cubital joint

What are the intrinsic caudal muscles of the brachium?

tensor fasciae antebrachii, triceps brachii, and anconeus

Triceps brachii long head origin

Long head of triceps brachii originates on caudal border of scapula

Triceps  brachii lateral heads

The lateral head of triceps brachii originates on proximal humerus

Triceps  brachii lateral, acessory, and medial

The triceps brachii lateral, accessory, and medial heads originate on proximal humerus

Triceps brachii termination

Triceps brachii terminates on the olecranon

Triceps brachii action

Triceps brachii extends the cubital joint

What is the additional action of the longhead of the triceps brachii?

longhead flexes the humeral joint

What are the intrinsic craniolateral muscles of the forearm?

extensor carpi radialis, common digital extensor, lateral digital extensor, ulnaris lateralis, supinator, abductor pollicis longus, brachioradialis

Extensor carpi radialis origin

Extensor carpi radialis originates on lateral epicondyle of the humerus

Extensor carpi radialis termination

Extensor carpi radialis terminates on second and third metacarpal bones

Extensor carpi radialis action

Extensor carpi radialis extends the carpal joints

Common digital extensor origin

Common digital extensor originates on the lateral epicondyle of the humerus

Common digital extensor termination

Common digital extensor terminates on distal phalanges

Common  digital  extensor action

Common digital extensor extends the carpal and digital joints of 2, 3, 4, 5

Lateral digital extensor origin

Lateral digital extensor originates on lateral epicondyle of the humerus

Lateral digital extensor termination

Lateral digital extensor terminates on lateral distal phalanges

Lateral digital extensor action

Lateral digital extensor extends the carpal joints and the digital joints of 3, 4, and 5

Extensor carpi ulnaris m. (ulnaris lateralis m.) origin

Ulnaris lateralis originates on the lateral epicondyle of the humerus

Extensor carpi ulnaris m. (ulnaris lateralis m.) termination

Ulnaris lateralis terminates on accessory carpal bone and fifth metacarpal bone

Extensor carpi ulnaris m. (ulnaris lateralis m.) action

Ulnaris lateralis flexes the carpal joints; abduct the manus

Supinator origin

Supinator originates on lateral epicondyle of the humerus

Supinator termination

Supinator terminates on the radius

Supinator action

Supination of the manus

Abductor pollicis action

abduct the first digit

What are the Caudomedial muscles of the antebrachium?

Flexor carpi ulnaris, superficial digital flexor, deep digital flexor, flexor carpi radialis, pronator teres, and pronator quadratus

Flexor carpi radialis origin

Flexor carpi radialis originates on medial epicondyle of the humerus

Flexor carpi radialis termination

Flexor carpi radialis terminates on metacarpal bones 2 and 3

Flexor carpi radialis action

Flexor carpi radialis flexes the carpal joints

Flexor carpi ulnaris origin

Flexor carpi ulnaris originates on the medial epicondyle of the humerus

Flexor carpi ulnaris termination

Flexor carpi ulnaris terminates on accessory carpal bone

Flexor carpi ulnaris action

Flexor carpi ulnaris flexes the carpal joints

Superficial digital flexor origin

Superficial digits flexor originates on medial epicondyle of the humerus

Superficial digital flexor termination

Superficial digital flexor terminates on middle phalanges of the digits

Superficial digital flexor action

Superficial digital flexor flexes the carpal joints, metacarpophalangeal and proximal interphalangeal joints

Deep digital flexor origin

Deep digital flexor originates on medial epicondyle of the humerus

Deep digital flexor termination

Deep digital flexor terminates on distal phalanges

Deep digital flexor action

Deep digital flexor flexes the carpal and digital joints

Pronator teres origin

Pronator teres originates on medial epicondyle of the humerus

Pronator teres termination

Pronator teres terminates on radius