Origins, Insertions, and Actions of Muscles

Question 1

biceps brachii

Answer 1

origin: supraglenoid tubercle / coracoid process
insertion: radial tuberosity
action: flex and supinate forearm

Question 2

sternocleidomastoid

Answer 2

origin: manubrium, clavicle
insertion: mastoid process
action: flexion of neck, head rotation

Question 3

digastric

Answer 3

origin: lower mandible / mastoid process
insertion: hyoid bone
action: elevates and retracts hyoid bone

Question 4

rectus abdominis

Answer 4

origin: pubic crest, symphysis
insertion: xiphoid process, costal cartilages of ribs 5-7
action: flexes and rotates vertebral column

Question 5

external oblique

Answer 5

origin: anterior surface of ribs 5-12
insertion: linea alba, pubic crest & tubercles, iliac crest
action: flexes vertebral column & compresses abdominal wall

Question 6

internal oblique

Answer 6

origin: lumbar fascia, iliac crest, inguinal ligament
insertion: linea alba, pubic crest, costal cartilages of ribs 10-12
action: flexes vertebral column & compresses abdominal wall

Question 7

transversus abdominis

Answer 7

origin: inguinal ligament, iliac crest, costal cartilages of ribs 7-12
insertion: linea alba, pubic crest
action: compresses abdominal wall

Question 8

soleus

Answer 8

origin: head of fibula, medial border of tibia
insertion: calcaneus via calcaneal tendon
action: plantar flexes foot

Question 9

gastrocnemius

Answer 9

origin: lateral & medial condyles of femur
insertion: calcaneus via calcaneal tendon
action: plantar flexes foot

Question 10

tibialis anterior

Answer 10

origin: lateral condyle & body of tibia
insertion: 1st metatarsal & a tarsal
action: dorsiflexes & inverts foot

Question 11

sartorius

Answer 11

origin: anterior superior iliac spine
insertion: proximal, medial tibia
action: flexes, abducts, & laterally rotates thigh, flexes leg

Question 12

gracilis

Answer 12

origin: pubis
insertion: proximal, medial tibia
action: adducts, flexes, medially rotates thigh

Question 13

erector spinae

Answer 13

origin: iliac crest, transverse processes of lumbar, thoracic, & cervical vertebrae, and/or ribs 3-6
insertion: ribs & transverse processes of vertebrae above origin, longissimus also inserts on mastoid
action: extends & laterally flexes vertebral column; fibers of the longissimus also extend head