Exam 2 Actions, Origins, & Insertions

Question 1

Superficial pectoral m.

Answer 1

Origin: sternum

Insertion: crest of greater tubercle and cranial humeral border

Action: adduct the thoracic limb

Question 2

Deep pectoral m.

Answer 2

Origin: sternum

Insertion: greater and lesser tubercles of humerus

Action: adduct thoracic limb and pull it caudally

Question 3

Brachiocephalicus m.

Answer 3

Origin: clavicular intersection

Insertion:

cleidobrachialis: distal cranial humerus

cleidocephalicus:

mastoid part: mastoid process of temporal bone

cervical part: dorsal midline of neck

Action: pull thoracic limb cranially (and/or) depress and pull head and neck laterally

Question 4

Omotransversariusm.

Answer 4

Cranial-most attachment: wing of atlas

Caudal-most attachment: distal spine of scapula

Action: pull thoracic limb cranially (and/or) depress and pull head and neck laterally

Question 5

Trapezius m.

Answer 5

Origin:

cervical part: dorsal neck

thoracic part: dorsal thorax

Insertion: spine of the scapula

Action: elevate the thoracic limb

Question 6

Rhomboideus m.

Answer 6

Origin:

rhomboideus thoracis: dorsal thorax

rhomboideus cervicis: dorsal neck

rhomboideus capitis: nuchal crest of occipital bone

Insertion: dorsal border of scapula and/or scapular cartilage

Action: elevate the thoracic limb

Question 7

Serratus ventralis m.

Answer 7

Origin:

serratus ventralis cervicis: cervical vertebrae

serratus ventralis thorais: thoracic wall (ribs)

Insertion: serrated face of scapula

Action: support and/or elevate the trunk

Question 8

Latissimus dorsi m.

Answer 8

Origin: thoracolumbar fascia

Insertion: teres major tuberosity

Action: draw the thoracic limb caudally, flex or extend the humeral joint

Question 9

Deltoideus m.

Answer 9

Origin: spine of the scapula and acromion

Insertion: deltoid tuberosity

Action: extend the humeral joint

Question 10

Supraspinatus m.

Answer 10

Origin: supraspinous fossa of the scapula

Insertion: greater tubercle of the humerus

Action: flex humeral joint (varies); abduct limb at humeral joint

Question 11

Infraspinatus m.

Answer 11

Origin: infraspinous fossa of the scapula

Insertion: greater tubercle of the humerus

Action: flex the humoral joint; abduct the limb at humeral joint

Question 12

Teres minor m.

Answer 12

ID only

Question 13

Subscapularis m.

Answer 13

Origin: subscapular fossa of scapula

Insertion: lesser tubercle of humerus

Action: adduct limb at humeral joint

Question 14

Teres major m.

Answer 14

Origin: caudal border of scapula

Insertion: teres major tuberosity of humerus

Action: flex the humeral joint

Question 15

Coracobrachialis m.

Answer 15

Origin: coracoid process of scapula

Question 16

Biceps brachii m.

Answer 16

Origin: supraglenoid tubercle

Insertion: radial and ulnar tuberosities

Action: flex the cubital joint and extend the humeral joint

Question 17

Brachialis m.

Answer 17

Origin: brachial groove of humerus

Insertion: proximal radius andulna

Action: flex the cubital joint

Question 18

Triceps brachii m.

long, lateral, medial and accessory heads

Answer 18

Origin: caudal border of scapula (long head); proximal humerus (other heads)

Insertion: tuber olecrani

Action: extend the cubital joint (all heads); flex the humeral joint (long head)

Question 19

Tensor fasciae antebrachii m.

Answer 19

Origin: latissimus dorsi and associated fascia

Insetion: tuber olecrani

Action: extend the cubital joint

Question 20

Extensor carpi radialis m.

Answer 20

Origin: lateral epicondyle of the humerus

Insertion: dorsal base of second and third metacarpal bones

Action: extend the carpal joints

Question 21

Common digital extensor m.

Answer 21

Origin: lateral epicondyle of the humerus

Insertion: extensor processes of the distal phalanges

Action: extend the carpal and digital joints

Question 22

Lateral digital extensor m.

Answer 22

Origin: lateral epicondyle of the humerus

Insertion: distal phalanges of lateral digit(s)

Action: extend the carpal and digital joints of the lateral-most digits

Question 23

Ulnaris lateralis m.

Answer 23

Origin: lateral epicondyle of the humerus

Insertion: accessory carpal bone and lateral base of 5th metacarpal bone

Action: flex the carpal joints; abduct the manus

Question 24

Supinator m.

Answer 24

ID only

Question 25

Flexor carpi radialis m.

Answer 25

Origin: medical epicondyle of the humerus Insertion: palmar base of metacarpal bones 2 and 3 Action: flex the carpal joints

Question 26

Flexor carpi ulnaris m.

Answer 26

Origin: medial epicondyle and olecrenon Insertion: accessory carpal bone Action: flex the carpal joint (humeral and ulnar heads!)

Question 27

Superficial digital flexor m.

Answer 27

Origin: medial epicondyle of the humerus Insertion: middle phalanges of the digits (palmar aspects) Action: flex the carpal joints, metacarpophalangeal, and proximal interphalangeal joints

Question 28

Deep digital flexor m.

Answer 28

Origin: humerus (medial epicondyle), radius, ulna Insertion: flexor tubercules of distal phalanges Action: flex the carpal and distal joints

Question 29

Pronator teres m.

Answer 29

Origin: medial epicondyle of the humerus Insertion: medial body of radius Action: weak elbow flexion and weak pronation of the manus

Question 30

Pronator quadratus m.

Answer 30

Attachments: apposed surfaces of the radius and the ulna Action: pronation of the manus

Question 31

Interossei muscles (assocaited with proximal sesamoid bones)

Answer 31

Origin: palmar base of respective metacarpal bone Insertion: palmar base of respective proximal phalanx (& tendon of common digital extensor dorsally) Action: flexes and supports metacarpophalangeal joint