Neck muscle flexors

Question 1

Longus coli

Answer 1

*Origin and insertion:
Upper section - from transverse processess below to anterior tubercle of atlas
Middle section - From vertebral bodies below to vertebral bodies above
Lower section- from vertebral bodes below to transverse processes above

*Action:
Bilateral- neck flexion

*Nerve supply:
Ventral rami (C3-C6)

Question 2

Sternocleidomastoid

Answer 2

Origin:
sternal head- upper surface of manubrium
Clavicular head: Upper surface of medial 1/3 of calvicle

Insertion: Mastoid process of skull

Direction: Upwards

Action:

• asssists with resperation
• bilateral action- neck flexion (posterior fibres may also extend head on neck at AO joint)
• Unilateral action- ipsilateral ateral flexion and contralateral rotation

Nerve supply:
motor- spinal part of accessory nerve (cranial nerve 11)
Sensory- ventral rami (C2,3)

Question 3

Scalenus anterior

Answer 3

Origin:
transverse processes of cervical spine

insterion:
1st rib

direction:
Downwards and laterally

Action:

• Assissts with respiration
• Bilateral action - neck flexion
• unilateral action - ipsilateral lateral flexion and contralateral roation

Nerve supply- Ventral rami cervical spine (C3-C8)

Question 4

Longus capitis

Answer 4

Origin:
Transverse processes

Insertion:
anterolateral occipital bone

Direction:
Upwards and medially

Action:
Bilateral action- neck flexion

Nerve supply:
ventral rami (C1-3)

Question 5

Rectus capitis anterior

Answer 5

Origin:
anterior surface of lateral mass of atlas and root of its transverse process

Insertion:
occipital bone

Action:
flexes neck

Nerve supply:
anterior primary rami (C1,2)