Cervical muscles

Question 1

Platysma

Answer 1

O: Skin/fascia of infra- and supraclavicular regions
I: Inferior border of mandible, and skin over lower face and angle of mouth
A: Depresses mandible and angle of mouth, tenses skin of lower face and anterior neck
In: Cervical branch of facial n. (CN VII)

Question 2

Longus colli - superior oblique part

Answer 2

O: Anterior tubercles of the TP of C3-C5
I: Anterior tubercle of atlas
A: Bilateral neck flexion
Unilateral neck lateral flexion (ipsilateral) and contralateral rotation
In: Anterior rami of spinal nerves C2-C6

Question 3

Longus colli - vertical part

Answer 3

O: Anterior surface of vertebral bodies of C5-T3
I: Anterior surface of vertebral bodies of C2-C4
A: Bilateral neck flexion
Unilateral neck lateral flexion (ipsilateral) and contralateral rotation
In: Anterior rami of spinal nerves C2-C6

Question 4

Longus colli - inferior oblique part

Answer 4

O: Anterior surface of vertebral bodies of T1-T3
I: Anterior tubercles of TP of C5-C6
A: Bilateral neck flexion
Unilateral neck lateral flexion (ipsilateral) and contralateral rotation
In: Anterior rami of spinal nerves C2-C6

Question 5

Longus capitis

Answer 5

O: Anterior tubercle of TP of C3-C6
I: Basilar part of occipital bone
A: Bilateral head flexion
Unilateral slight head ipsilateral rotation
In: Anterior rami of spinal nerves C1-C3

Question 6

Anterior scalene

Answer 6

O: Anterior tubercle of TP of C3-C7
I: Scalene tubercle, and superior border of 1st rib (anterior to subclavian groove)
A:
Bilateral: neck flexion
Unilateral: neck lateral flexion (ipsilateral), neck rotation (contralateral), and elevates 1st rib
In: Anterior rami of spinal n. C4-C6

Question 7

Middle scalene

Answer 7

O: TP of C1-C2, and posterior tubercles of TP of C3-C7
I: Superior border of 1st rib (posterior to subclavian groove)
A: Neck lateral flexion and elevates 1st rib
In: Anterior rami of spinal nerves C3-C8

Question 8

Posterior scalene

Answer 8

O: Posterior tubercles of TP of C5-C7
I: External surface of 2nd rib
A: Neck lateral flexion and elevates 2nd rib
In: Anterior rami of spinal nerves C6-C8

Question 9

Sternocleidomastoid

Answer 9

O:
Sternal head: superior part of anterior surface of manubrium
Clavicular head: superior surface of medial third of the clavicle
I: Lateral surface of mastoid process of the temporal bone, and Lateral half of superior nuchal line of the occipital bone
A: Unilateral head ipsilateral sidebending and contralateral rotation
Bilateral head/neck extension (upper cx.), neck flexion (lower cx.), and aids in respiration when head is fixed (elevation of clavicle and manubrium of sternum)
In:
Motor: Accessory nerve (CN XI)
Proprioception: Branches of cervical plexus (C2-C3)