Cat Muscles - Shoulder Muscles

Question 1

Latissimus dorsi

Answer 1

Origin: Neural spines of last thoracic and most lumbar; lumbodorsal fascia
Insertion: Tendon on medial surface of humerus
Action: Retraction of humerus

Question 2

Levator scapulae ventralis

Answer 2

Origin: Transverse process of atlas & occipital bone
Insertion: Metacromion process and nearby fascia
Action: Draws scapula craniad

Question 3

Clavotrapezius

Answer 3

Origin: Superior nuchal line; medial dorsal line of neck
Insertion: Clavicle
Action: Draws clavicle dorsad and craniad

Question 4

Acromiotrapezius

Answer 4

Origin: Neural spines of cervical and 1st thoracic
Insertion: Metacromion process and spine of scapula, fascia of spinotrapezius
Action: Draws scapula dorsad, holds two scapula together

Question 5

Spinotrapezius

Answer 5

Origin: Spines of thoracic vertebrae
Insertion: Fascia of scapula
Action: Draws scapula dorsad and caudad

Question 6

Clavodeltoid

Answer 6

Origin: Clavicle and fibers of clavotrapezius
Insertion: Ulna
Action: Protracts arm or flexes forearm

Question 7

Acromiodeltoid

Answer 7

Origin: Acromion of scapula
Insertion: Spinodeltoid and brachialis muscles & deltoid region of humerus
Action: Retracts and abducts humerus

Question 8

Spinodeltoid

Answer 8

Origin: Spine of scapula
Insertion: Deltoid ridge of humerus
Action: retracts and abducts the humerus

Question 9

Rhomboideus

Answer 9

Origin: Neural spines of vertebrae and adjacent ligaments
Insertion: Vertebral border of scapula
Action: Draws scapula dorsad and mediad

Question 10

Rhomboideus capitis

Answer 10

Origin: Superior nuchal line
Insertion: Scapula
Action: Draws scapula craniad or rasies head

Question 11

Supraspinatus

Answer 11

Origin: Supraspinous fossa
Insertion: Greater tuberosity of humerus
Action: Extends/protracts humerus

Question 12

Infraspinatus

Answer 12

Origin: Infraspinous fossa
Insertion: Greater tuberosity of humerus
Action: Rotates the humerus outward

Question 13

Teres major

Answer 13

Origin: Glenoid border of scapula and fascia of neighboring muscles
Insertion: Medial surface of humerus
Action: Rotates humerus and retracts it

Question 14

Teres minor

Answer 14

Origin: Glenoid border of scapula
Insertion: Greater tuberosity of humerus
Action: Rotates humerus outward

Question 15

Subscapularis

Answer 15

Origin: Subscapular fossa
Insertion: Lesser tuberosity of humerus
Action: Pulls humerus medially