ONIA: Neck

Mylohyoid Nerve

Mandibular N. CNV3 (Nerve to mylohyoid)

Mylohyoid Action

Elevates hyoid floor of mouth and tongue during swallowing & speaking

Digastric Nerve

Mandibular N CNV3 (Nerve to mylohyoid) & Digastric branch of facial N (CN VII)

Digastric Action

Depresses mandible against resistance; elevates and steadies hyoid during swallowing & speaking

Geniohyoid Nerve

C1 via hypoglossal N. (CN XII) & Nerve to geniohyoid

Geniohyoid Action

Pulls hyoid anterosuperiorly; shortens floor of mouth; widens pharynx

Stylohyoid Nerve

Stylohyoid branch of facial N. (CN VII)

Stylohyoid Action

Elevates and retracts hyoid, thus elongating floor of mouth

Sternohyoid Nerve

C1-C3 by a branch of ansa cervicalis

Sternohyoid Action

Depresses hyoid after elevation during swallowing

Omohyoid Nerve

C1-C3 by a branch of ansa cervialis

Omohyoid Action

Depressed, retracts, and steadies hyoid

Sternothyroid Nerve

C2 and C3 by a branch of anse cervicalis

Sternothyroid Action

Depresses hyoid and larynx

Thyrohyoid Nerve

C1 via hypoglossal N. (CN XII) and N. to thyrohyoid

Thyrohyoid Action

Depresses hyoid and elevates larynx

Longus Colli Superior attachment

Ant. tubercle of C1; Bodies of C1-C3 and TP of C3-C6

Longus Colli Inferior attachment

Bodies of C5-T1; TP of C3-C5

Longus colli Nerve

Ant. rami C2-C6

Longus Colli Action

Flexes neck with rotation to opposite side if acting unilaterally

Longus Capitis Superior attachment

Basilar part of occipital bone

Longus Capitis Inferior attachment

Ant. tubercles of C3-C6 TP

Longus capitis Nerve

Ant. rami of C1-C3

Longus capitis Action

Flex head

Rectus capitis Ant. Superior attachment

Base of cranium, just anterior to occipital condyle

Rectus capitis Ant. inferior attachment

Anterior surface of lateral mass of atlas

Rectus Capitis Ant. Nerve

Branches from loop between C1 and C2

Rectus Capitis Ant. Action

Flex head

Rectus Capitis Lateralis Superior attachment

Jugular process of occipital bone

Rectus Capitis Lateralis Inferior attachment

TP of atlas

Rectus Capitis Lateralis Nerve

Branches from loop between C1-C2 spinal N.

Rectus Capitis Lateralis Action

Flexes head & helps stabilizes it

Anterior Scalene Superior attachment

TP of C3-C6

Anterior Scalene Inferior attachment

1st rib

Anterior Scalene Nerve

Cervical spinal N C4-C6

Anterior Scalene Action

Flexes neck laterally; elevates 1st rib during forced inspiration

Middle Scalene Superior attachment

Post. tubercles of TP of C5-C7

Middle Scalene Inferior attachment

Superior surface of 1st rib; Post. to groove for subclavian A.

Middle scalene Nerve

Anterior rami of cervical spinal N.

Middle scalene Action

Flexes neck laterally; elevates 1st rib during forced inspiration

Posterior scalene Superior attachment

Post. tubercles of TP of C5-C7

Posterior Scalene inferior attachment

External border of 2nd rib

Posterior Scalene Nerve

Anterior rami of C7 & C8

Posterior Scalene Action

Flexes neck laterally; 2nd rib during forced inspiration

Platysma Superior/Medial attachment

Inferior border of mandible, skin, and subcutaneous tissue of lower face

Platysma Inferior/Lateral attachment

Fascia covering superior parts of pectoralis major and deltoid muscles

Platysma Nerve

Cervical branch of facial N (CN VII)

Platysma Action

Draws corners of mouth inferiorly and widens it as in expressions of sadness and fright; draws skin of neck superiorly when teeth are clenched

SCM Superior/Medial attachment

Lateral surface of mastoid process of temporal bone and lateral half of superior nuchal line

SCM Inferior/Lateral attachment

Sternal head: Ant. surface of manubrium of sternum

Clavicular head: superior surface of medial third of clavicle

SCM Nerve

Spinal accessory N (CN XI motor); C3-C4 (pain & proprioception)

SCM Action

Unilateral: tilts head to same side and rotates it so face is turned superiorly to opposite side

Bilateral: Extends neck at OA joint, flexes cervical so that chin approaches manubrium, extends superior c/s while flexing inferior vertebrae, with c/s fixed may elevate manubrium and medial ends of clavicles, assiting pump-handle action of deep respiration