Cat Dissection Muscles

latissimus dorsi

extends and adducts humerus

Clavotrapezius (cat)

Origin: Occipital bone and spines of cervical and thoracic vertebrae

Insertion: Clavicle, acrominon and spine of scapula

Action: Elevates, depresses, and aducts scapula; hyperextends neck.

Acromiotrapezius

Origin: spines of cervical vertebrae

Insertion: spine of scapula

Action: pulls scapula dorsally

Spinotrapezius

origin: spines of thoracic vertebrae

insertion: spine of scapula

action: pulls scapula back and caudal

Clavodeltoid

Origin: clavicle

Insertion: ulna

Action: flexes forearm

Acromiodeltoid (cat)

Origin: Clavicle, acromion, and spine of scapula

Insertion: Deltoid tuberosity of humerus

Action: Abducts, extends or flexes shoulder joint.

Spinodeltoid

Origin: spine of the scapula

Insertion: deltoid ridge of the humerus

Action: flexes and rotates humerus

levator scapulae

origin: transverse processes of C1-C4

insertion: medial border of scapula superior to spine

action: elevates and adducts scapula

Rhomboid major

origin: spinous processes of T2-T5

insertion: medial border of scapula

Rhomboid minor

retracts scapula

Occipitoscapularis

Origin- Posterior of skull

Insertion- Scapula

Action- Pulls scapula anteriorly

Splenius

extends and rotates head

Iliocostalis

Origin: muscle bundles from lower thoracic ribs

Insertion: three ribs craniad to the origin of each bundle

Action: draws ribs together

Longissimus dorsi

Origin: sacral and caudal vertebrae

Insertion: thoraco-cervical vertebrae

Action: extends vertebral column

longissimus cervicis

Origin: transverse processes of superior thoracic vertebrae

Insertion: transverse process of middle and superior cervical vertebrae

Action:

Bilateral extend head

Unilateral laterally flexes neck to same side

Innervation: Cervical and thoracic spinal nerves

longissimus capitis

Origin: Upper thoracic and lower cervical vertebrae

Insertion: Mastoid process of temporal bone

Action: Extends and rotates head

Spinalis dorsi

Action: extends vertebral column

serratus anterior

pulls scapula anteriorly and downward

teres major

Origin: Scapula

Insertion: Humerus

teres minor

origin: lateral border of scapula

insertion: greater tubercle of humerus

Supraspinatus

origin: supraspinous fossa of scapula

insertion: greater tubercle of humerus

Infraspinatus

origin: infraspinous fossa of scapula

insertion: greater tubercle of humerus

Multifidus

-Origin Sacrum, Erector spinae Aponeurosis, PSIS, and Iliac crest

-Insertion spinous process

-Actions

=Bilateral backward extension,

= unilateral side-bending to the ipsilateral side

=rotation to the contralateral side

Serratus posterior

assist in ventilating the lungs

Semispinalis Cervicis

Extend spine/rotate spine to opposite side

Cephalic vein

Large vein on the outermost side of the upper arm

Biceps brachii

flexes forearm

Epitrochlearis

Origin: latissimus dorsi

Insertion: olecranon process

Action: extends forearm

Triceps brachii, long head

infraglenoid tubercle of scapula

triceps brachii, medial head

O: distal posterior surface of humerus

I: olecranon process of ulna

A: extends forearm/elbow

triceps brachii, lateral head

O: proximal posterior surface of humerus

I: olecranon process of ulna

A: extends forearm/elbow

brachialis

Origin: humerus

Insertion: ulna

Action: flexes forearm

brachioradialis

Origin: humerus

Insertion: radius

Action: flexes forearm

Anconeus

Origin: Lateral Epicondyle of Humerus

Insertion: Olecranon

Pronator teres

origin: medial epicondyle of humerus

insertion: radius

action: pronates forearm

flexor carpi ulnaris

-Origin Medial epicondyle (common flexor tendon) and medial margin on olecranon of ulna

-Insertion Pisiform, hook of the hamate, base of the fifth metacarpal bone

-Nerve ulnar nerve

Nerve root C7, C8 and T1

-Actions Flexion and adduction of wrist

-Antagonist Extensor carpi radialis brevis muscle and extensor carpi radialis longus muscle

flexor carpi radialis

Origin: Medial epicondyle of humerus

Insertion: Bases of second and third metacarpal bones

Action: Flexion and abduction at wrist

palmaris longus

origin: medial epicondyle of humerus

insertion: palmar aponeurosis

flexor digitorum profundus

origin: ulna

insertion: phalanges

action: flexes distal joints of fingers

extensor carpi radialis longus

Origin: lateral supracondylar ridge of humerus

Insertion: base of metacarpal II

Action: extends and abducts hand

extensor carpi radialis brevis

origin: lateral epicondyle of humerus

insertion: metacarpal III

extensor digitorum communis

origin: humerus

insertion: phalanges

action: extends fingers and wrist

extensor digitorum lateralis

Origin: lateral supracondylar ridge of humerus

Insertion: digits

Action: extends digits

extensor carpi ulnaris

Origin: Lateral epicondyle of the humerus

Insertion: 5th metacarpal

Action: Extends the hand

supinator

Origin: Lateral epicondyle of humerus

Insertion: Radius

Action: Supinates forearm

extensor pollicis brevis

Origin radius and the interosseous membrane

Insertion thumb, proximal phalanx

Nerve posterior interosseous nerve

Actions extension of thumb at metacarpophalangeal joint

Antagonist Flexor pollicis longus muscle, Flexor pollicis brevis muscle

extensor indicis proprius

Origin: Upper third of ulna

Insertion: Middle phalanx of digit 2

Action: Extends digit 2

Sternomastoid

Origin: manubrium

Insertion: lambdoidal ridge and mastoid process

Action: turns and lowers head

Cleidomastoid

Origin: mastoid process

Insertion: clavicle

Action: turns and lowers head

Sternohyoid

origin: manubrium and clavicle

insertion: hyoid bone

Digastric

Origin: mandible

Insertion: hyoid bone

Action: opens mouth

Mylohyoid

Origin: mandible

Insertion: median raphe

Action: raises floor of mouth

Subscapularis

origin: subscapular fossa of scapula

insertion: lesser tubercle of humerus