Muscles: Origins, Insertions and Actions

Question 1

Temporalis

Answer 1

Origin: temporal bone
Insertion: coronoid process of the mandible
Action: raises the mandible

Question 2

Masseter

Answer 2

Origin: zygomatic bone
Insertion: angle and ramus of the mandible
Action: raises the mandible

Question 3

Sternocleidomastoid

Answer 3

Origin: manubrium of sternum and medial portion of the clavicle
Insertion: mastoid process of the temporal bone
Action: flexes the cervical vertebral column

Question 4

Trapezius

Answer 4

Origin: occipital bone and ligamentum nuchae
Insertion: clavicle; acromion and spine of scapula
Action: rotates, adducts, and stabilizes the scapula

Question 5

Levator Scapulae

Answer 5

Origin: transverse process of upper cervical vertebrae
Insertion: vertebral border of the scapula
Action: elevates the scapula

Question 6

Pectoralis Major

Answer 6

Origin: medial half of the clavicle and the sternum
Insertion: intertubercular groove of humerus
Action: flexes, adducts, and medially rotates the arm

Question 7

Latissimus Dorsi

Answer 7

Origin: spinous processes of lower thoracic vertebrae
Insertion: intertubercular roof of humerus
Action: extends, adducts, and medially rotates arm

Question 8

Deltoid

Answer 8

Origin: clavicle; acromion and spine of scapula
Insertion: deltoid tuberosity of the humerus
Action: abducts the arm

Question 9

Supraspinatus

Answer 9

Origin: supraspinatus fossa of the scapula
Insertion: greater tubercle of the humerus
Action: abducts the arm

Question 10

Infraspinatus

Answer 10

Origin: infraspinatus fossa of the scapula
Insertion: greater tubercle of the humerus
Action: rotates the arm laterally

Question 11

Subscapularis

Answer 11

Origin: subscapular fossa of the scapula
Insertion: lesser tubercle of the humerus
Action: rotates the arm medially

Question 12

Subscapularis

Answer 12

Origin: subscapular fossa of the scapula
Insertion: lesser tubercle of the humerus
Action: rotates the arm medially

Question 13

Biceps Brachii

Answer 13

Origin: coracoid process of the scapula
Insertion: radial tuberosity of the radius
Action: flexes the forearm and arm; supination of forearm

Question 14

Triceps Brachii (long, lateral, and medial heads)

Answer 14

Origin: infraglenoid tubercle of scapula and post surface of humerus
Insertion: olecranon process of the ulna
Action: extends forearm

Question 15

Flexor Carpi Radialis

Answer 15

Origin: medial epicondyle of the humerus
Insertion: 2nd and 3rd metacarpals
Action: flexes hand

Question 16

Extensor Carpi Ulnaris

Answer 16

Origin: lateral epicondyle of the humerus
Insertion: 5th metacarpal
Action: extends hand

Question 17

Extensor Carpi Radialis Longus

Answer 17

Origin: supracondylar ridge of the humerus
Insertion: 2nd metacarpal
Action: extends hand

Question 18

Gluteus Maximus

Answer 18

Origin: gluteal line of the ilium
Insertion: gluteal tuberosity of the femur
Action: extends and laterally rotates thigh

Question 19

Iliacus

Answer 19

Origin: iliac crest
Insertion: lesser trochanter of the femur
Action: flexes thigh

Question 20

Psoas Major

Answer 20

Origin: transverse processes of the lumbar vertebrae
Insertion: lesser trochanter of the femur
Action: flexes thigh

Question 21

Adductor Magnus

Answer 21

Origin: inferior ramus of the pubis and ischium
Insertion: linea aspera of the femur
Action: adducts the thigh

Question 22

Gracilis

Answer 22

Origin: pubic symphysis
Insertion: medial surface of the tibia
Action: adducts thigh

Question 23

Sartorius

Answer 23

Origin: anterior superior iliac spine
Insertion: medial surface of the tibia
Action: flexes the thigh and leg

Question 24

Rectus Femoris

Answer 24

Origin: anterior inferior iliac spine
Insertion: tibial tuberosity of the tibia
Action: flexes the thigh and extends the leg

Question 25

Vastus Lateralis

Answer 25

Origin: greater trochanter of the femur Insertion: tibial tuberosity of the tibia Action: extends leg

Question 26

Vastus Lateralis

Answer 26

Origin: greater trochanter of the femur Insertion: tibial tuberosity of the tibia Action: extends leg

Question 27

Biceps Femoris

Answer 27

Origin: ischial tuberosity and linea aspera of the femur Insertion: head of the fibula and lateral condyle of the tibia Action: flexes leg and extends thigh

Question 28

Semimembranosis

Answer 28

Origin: ischial tuberosity Insertion: proximal end of the tibia Action: flexes leg and extends thigh

Question 29

Tibialis Anterior

Answer 29

Origin: lateral condyle of the tibia Insertion: 1st metatarsal Action: dorsiflexes and inverts the foot

Question 30

Gastrocnemius

Answer 30

Origin: medial and lateral condyles of the femur Insertion: calcaneus bone Action: plantar flexes and inverts foot