Muscles of the Upper Body

Question 1

Trapezius - name origin, insertion and actions

Answer 1

Origin - occiput, ligamentum nuchae, SP’s C7-T12
Insertion - spine of scapula, lateral clavicle, acromion process
Actions - upward rotation of scapula
- upper fibres - lateral flexion, extension and contralateral rotation of neck and head. Elevation of scapula
- middle fibres - retraction of scapula
- lower fibres - depression of scapula

Question 2

Splenius capitis - name origin, insertion and actions

Answer 2

Origin - inferior half of ligamentum nuchae, SP’s of C7-T4
Insertion - mastoid process, lateral occiput
Actions -
- unilateral - ipsilateral rotation and lateral flexion of the neck and head
- bilateral - extension of the neck and head

Question 3

Levator scapula - name origin, insertion and actions

Answer 3

Origin - TP’s of C1-C4
Insertion - medial border of scapula between superior angle and root of spine of scapula
Actions - elevation, retraction and downward rotation of scapula. Extension, lateral flexion and ipsilateral rotation of head and neck

Question 4

Suboccipitals - name origin, insertion and actions

Answer 4

Origin - SP of C2, posterior tubercle of C1, TP’s of C1
Insertion - TP’s of C1, occiput
Actions - extension, rotation and lateral flexion of head

Question 5

Temporalis - name origin, insertion and actions

Answer 5

Origin - temporal fossa and fascia
Insertion - coronoid process of ramus of mandible
Actions - elevates amd retracts mandible

Question 6

Masseter - name origin, insertion and actions

Answer 6

Origin - zygomatic arch
Insertion - angle and ramus of mandible
Actions - elevates and assists in protraction of the mandible

Question 7

Frontalis - name origin, insertion and actions

Answer 7

Origin: galea aponeurotica
Insertion: skin superior to eyebrows
Actions: raises eyebrows and wrinkles the forehead

Question 8

Sternocleidomastoid - name origin, insertion and actions

Answer 8

Origin:
- sternal head: top of manubrium
- clavicular head: medial third of clavicle
Insertion: mastoid process, lateral occiput
Actions: flexion of neck, extension of head, lateral flexion and contralateral rotation of neck and head, elevation of the sternum and clavicle

Question 9

Scalenes - name origin, insertion and actions

Answer 9

Origin:
     - anterior: TP's of C3-C6
     - middle: TP's of C2-C7
     - posterior: TP's of C5-C7
Insertion:
     - anterior and middle: first rib
     - posterior: second rib
Actions: 
     - unilateral: lateral flexion of neck and head (ribs fixed), contralateral rotation of neck and head
     - bilateral: elevation of ribs
     - anterior scalenes: flexion of neck and head