muscular system (lab)

Question 1

buccinator

Answer 1

action (compresses cheeks) origin (molar region of maxilla and mandible) insertion (orbicularis oris).

Question 2

epicranius frontalis

Answer 2

action (raises eyebrow and wrinkles forehead) origin (epicranial aponeurosis) insertion (skin of eyebrows and root of nose).

Question 3

epicranius occipitalis

Answer 3

action (raises the eyebrow; pulls scalp posteriorly), origin (occipital and temporal bones), insertion (epicranial aponeurosis).

Question 4

orbicularis oculi

Answer 4

action (closes eye tightly or squinting) no insertion or origin.

Question 5

orbicularis oris

Answer 5

action (closes and protrudes [puckers] lips), no origin or insertion.

Question 6

zygomaticus major and minor

Answer 6

action (raises corners of mouth [smiling]), origin (zygomatic bone), insertion (skin, muscle of upper lips).

Question 7

masseter

Answer 7

action (closes the jaw [mandible]), origin (zygomatic arch and bone), insertion (angle of mandible).

Question 8

temporalis

Answer 8

action (closes the jaw [elevates and retracts the mandible]) no origin or insertion.

Question 9

sternocleidomastoid

Answer 9

action (one side contracting = turning head to the opposite side, both sides contracting = pulling head toward chest, raising the sternum), origin (manubrium of sternum and medial portion of clavicle), insertion (mastoid process of temporal bone and superior nuchal line of occipital bone).

Question 10

platysma

Answer 10

action (draws the angles of the mouth downward) no insertion or origin.

Question 11

external oblique

Answer 11

action (tenses the abdominal wall; compresses the abdominal contents) no origin or insertion.

Question 12

internal oblique

Answer 12

action (tenses the abdominal wall; compresses the abdominal contents).

Question 13

rectus abdominis

Answer 13

action (flexes and rotates vertebral column; compresses the abdominal contents; also flexes the torso at the waist as in sit-ups), origin (pubic crest and symphysis), insertion (xiphoid process, costal cartilages of ribs 5-7).

Question 14

transversus abdominis

Answer 14

action (tenses the abdominal wall; compresses the abdominal contents). no origin and insertion.

Question 15

pectoralis major

Answer 15

action (pulls the arm forward and across the chest; adducts and medially rotates the humerus), origin (clavicle, sternum, cartilage of ribs 1-6, and aponeurosis of external oblique muscle), insertion (fibers converge to insert by short tendon into intertubercular sulcus of humerus).

Question 16

pectoralis minor

Answer 16

action (pulls the scapula forward and downward; raises the ribs), no origin and insertion.

Question 17

serratus anterior

Answer 17

action (pulls the scapula anteriorly and downward), no insertion and origin.

Question 18

diaphragm

Answer 18

action (enlarges the volume of the thoracic cavity to cause inhalation), no insertion and origin.

Question 19

external intercostals

Answer 19

action (causes forceful inhalation) no origin and insertion.

Question 20

internal intercostals

Answer 20

action (causes forceful exhalation), no insertion and origin.

Question 21

deltoid

Answer 21

action (abducts the humerus; flex or extend the humerus), origin (lateral 1/3 of clavicle; acromion and spine of scapula), insertion (deltoid tuberosity of humerus).

Question 22

latissimus dorsi

Answer 22

action (extends and adducts the humerus; pulls shoulder down and back), origin (indirect attachment to spinous processes of lower 6 thoracic vertebrae, lumbar vertebrae, last 3 to 4 ribs, and iliac crest), insertion (floor of intertuber cular sulcus of humerus).

Question 23

levator scapulae

Answer 23

action (elevates the scapula), origin (transverse processes of C1-C4), insertion (medial border of scapula superior to spine).

Question 24

rhomboid major

Answer 24

action (raises and adducts the scapula) no origin and insertion.

Question 25

teres major

Answer 25

action (extends, adducts, and medially rotates the humerus), no origin and insertion.

Question 26

teres minor

Answer 26

action (laterally rotates the humerus), no insertion and origin.

Question 27

trapezius

Answer 27

action (several movement of the scapula) origin (occipital bone; ligamentum nuchae; spines of C7 and all thoracic vertebrae) insertion (acromion and spinous process of scapula; lateral third of clavicle).

Question 28

biceps brachii

Answer 28

action (flexes the forearm at the elbow) origin (short head: coracoid process; long head: supraglenoid tubercle and lip of glenoid cavity; tendon of long head runs in the intertubercular sulcus and within capsule of shoulder joint), insertion (radial tuberosity).

Question 29

brachialis

Answer 29

action (flexes the forearm at the elbow, no origin and insertion.

Question 30

extensors

Answer 30

action (several muscles on the dorsal surface of the forearm which extend either the wrist of the fingers), no origin and insertion.

Question 31

flexors

Answer 31

action (several muscles on the anterior surface of the forearm which flex either the wrist or the fingers), no origin and insertion.

Question 32

infraspinatus

Answer 32

action (laterally rotates the humerus), no origin and insertion.

Question 33

subscapularis

Answer 33

action (medially rotates the humerus), no origin and insertion.

Question 34

supraspinatus

Answer 34

action (abducts the humerus), no origin and insertion.

Question 35

triceps brachii

Answer 35

action (extends the forearm at the elbow), origin (long head: inferior margin of glenoid cavity; lateral head: posterior humerus; medial head: distal radial groove on posterior humerus), insertion (olecranon of ulna).

Question 36

adductor longus, magnus, and brevis

Answer 36

action (adduct and medially rotate and flex the thigh), no origin and insertion.

Question 37

gastrocnemius

Answer 37

action (plantar flexes foot; flexes leg at knee), origin (by two heads from medial and lateral condyles of femur), insertion (calcaneus via calcaneal tendon).

Question 38

gluteus maximus

Answer 38

action (extends the thigh at the hip), origin (dorsal ilium, sacrum, and coccyx), insertion (gluteal tuberosity of femur and iliotibial tract).

Question 39

gluteus medius

Answer 39

action (abducts the thigh) no origin and insertion.

Question 40

gracilis

Answer 40

action (adducts the thigh) no origin and insertion.

Question 41

hamstrings (biceps femoris, semitendinosus, semimembranosus)

Answer 41

action (flex the leg; extend the thigh) origin (ischial tuberosity [long head]; linea aspera and distal femur [short head]), insertion (tendon passes laterally to insert into head of fibula and lateral condyle of tibia).

Question 42

iliopsoas (iliacus, psoas major)

Answer 42

action (flexes the thigh [or the torso] at the hip) no origin and insertion.

Question 43

quadriceps femoris (rectus femoris, vastus lateralis, medialis, and intermedius)

Answer 43

action (extend the leg at the knee and flexes thigh), origin (anterior inferior iliac spine and superior margin of acetabulum), insertion (tibial tuberosity and patella).

Question 44

sartorius

Answer 44

action (crosses the legs “tailior style”; a common cross-legged position when seated on floor), origin (anterior superior iliac spine), insertion (by an aponeurosis into the medial aspect of proximal tibia).

Question 45

tensor fasciae latae

Answer 45

action (abducts the thigh) no origin and insertion.

Question 46

tibialis anterior

Answer 46

action (dorsiflexion of the foot), origin (lateral condyle and upper 2/3 of tibia; interosseous membrane), insertion (by tendon into inferior surface of first cuneiform and metatarsal).