Cervical and Thoracic Spines (Myology)

Question 1

Trapezius

Answer 1

Action:
Elevation of the pectoral girdle
Retracts the scapula
Depresses the shoulder
Rotates the scapula
Extension and side flexion of the neck

Origin:
Medial third of the superior nuchal line
External occipital protruberance
Nuchal ligament
C7-12 vertebrae

Insertion:
Clavicle
Acromion
Spine of the scapula

Innervation:
Spinal root of the accessory nerve
Cervical nerves C3-4

Question 2

Sternocleidomastoid

Answer 2

Action:
Bilateral contraction causes neck flexion
Unilateral causes side flexion and rotation

Origin:
Sternal head
Manubrium
Clavicular head
Medial 1/3 of the clavicle

Insertion:
Mastoid Process
Nuchal line

Innervation:
Spinal accessory nerve
C2-3

Question 3

Scalenus Anterior

Answer 3

Action:
Bilateral contraction causes lifting of ribs
Unilateral causes side flexion

Origin:
C3-6 Transverse process

Insertion:
1st rib

Innervation:
Brachial plexus c5-7

Question 4

Scalenus Medius

Answer 4

Action:
Bilateral contraction causes lifting of ribs
Unilateral causes side flexion

Origin:
C1-7 transverse processes

Insertion:
1st rib

Innervation:
Brachial Plexus C3-8

Question 5

Scalenus Posterior

Answer 5

Action:
Bilateral contraction causes lifting of ribs
Unilateral causes side flexion

Origin:
C4-6 transverse processes

Insertion:
2nd rib

Innervation:
Brachial plexus C7-8

Question 6

Lattisimus Dorsi

Answer 6

Action:
Shoulder;
Adduction
Medial rotation
Extension

Origin:
Spinous processes T7-12
Thoracolumbar fascia
Iliac crest
Inferior ribs 3-4

Insertion:
Intertubercular groove of the humerus

Innervation:
Thoracodorsal Nerve C6-8

Question 7

Levator Scapulae

Answer 7

Action:
Pectoral Girdle;
Elevation
Medial rotation
Retraction
Unilateral contraction causes neck flexion and extension

Origin:
C1-4 transverse processes

Insertion:
Medial border of the scapula

Innervation:
Cervical nerve c3-4
Dorsal scapular nerve c5