Head and Neck Musculature

Muscle Regions of the Body:

	Head and neck
	Trunk, front and back
	Brachium, antibrachium & hand
	Thigh, leg & foot

Muscle Groups within this Region:

	Suboccipital
	Prevertebral
	Anterolateral Neck
	Superficial Neck
	Anterior Neck
	Epicranial
	Muscles of Facial Expression
	Muscles of Mastication
	Extraocular
	Laryngeal

Suboccipital Musculature

Obliquus capitis inferior

	Origin: spinous process of axis (C2)
	Insertion: transverse process of atlas (C1)
	Action: rotates the head to the contracted side
	Blood: muscular branches of vertebral artery
	Nerve: suboccipital nerve, (dorsal rami C1)

Obliquus capitis superior

	Origin: transverse process of atlas (C1)
	Insertion: between superior and inferior nuchal line of occiput
	Action: bilaterally extends the head laterally flexes to the contracted side
	Blood: muscular branches of vertebral artery
	Nerve: suboccipital nerve, (dorsal rami C1)

Rectus capitis posterior major

	Origin: spinous process of axis (C2)
	Insertion: inferior nuchal line (lateral to minor)
	Action: bilaterally extends the head rotates the head to the contracted side
	Blood: muscular branches of vertebral artery
	Nerve: suboccipital nerve, (dorsal rami C1)

Rectus capitis posterior minor

	Origin: posterior tubercle of atlas (C1)
	Insertion: inferior nuchal line (adjacent to midline)
	Action: bilaterally extends the head
	Blood: muscular branches of vertebral artery
	Nerve: suboccipital nerve, (dorsal rami C1)

Prevertebral Musculature

Longus colli

	Origin: lower anterior vertebral bodies and transverse processes
	Insertion: anterior vertebral bodies and transverse processes several segments above
	Action: flexes the head and neck
	Blood: muscular branches of the aorta
	Nerve: ventral rami C2-C6

Longus capitis

	Origin: upper anterior vertebral bodies and transverse processes
	Insertion: anterior vertebral bodies and transverse processes several segments above
	Action: flexes the head and neck
	Blood: muscular branches of the aorta
	Nerve: ventral rami C1-C3

Rectus capitis anterior

	Origin: anterior base of the transverse process of the atlas
	Insertion: occipital bone anterior to foramen magnum
	Action: flexes the head
	Blood: muscular branches of the aorta
	Nerve: ventral rami C2,3

Rectus capitis lateralis

	Origin: transverse process of the atlas
	Insertion: jugular process of the occipital bone
	Action: bends the head laterally
	Blood: muscular branches of the aorta
	Nerve: ventral rami C2,3

Anterolateral Neck Musculature

Anterior scalene

	Attachment A: anterior tubercles of transverse processes of C3-C6
	Attachment B: 1st rib
	Action: if transverse process fixed: elevates the ribs for respiration if ribs fixed: rotates to side opposite of contraction laterally flexes to the contracted side bilaterally flexes the neck
	Blood: inferior thyroid artery (branch of the thyrocervical trunk)
	Nerve: ventral rami C3-C6

Scalenus minimus (may be absent)

	Attachment A: anterior tubercles of transverse processes of C6 & 7
	Attachment B: 1st rib and/or supraplural membrane
	Action: if transverse process fixed: elevates the ribs for respiration if ribs fixed: rotates to side opposite of contraction laterally flexes to the contracted side bilaterally flexes the neck
	Blood: ascending cervical artery
	Nerve: variable (cervical and brachial plexus)

Middle scalene

	Attachment A: transverse processes of all cervical vertebrae
	Attachment B: 1st rib (behind anterior scalene)
	Action: if transverse process fixed: elevates the ribs for respiration if ribs fixed: rotates to side opposite of contraction laterally flexes to the contracted side bilaterally flexes the neck
	Blood: ascending cervical artery
	Nerve: ventral rami C3-C8

Posterior scalene

	Attachment A: posterior tubercles of transverse processes of C5 & C6
	Attachment B: 2nd and/or 3rd rib
	Action: if transverse process fixed: elevates the ribs for respiration if ribs fixed: rotates to side opposite of contraction laterally flexes to the contracted side bilaterally flexes the neck
	Blood: ascending cervical artery
	Nerve: ventral rami C5-C7

Superficial Neck Musculature

Sternocleidomastoid

	Origin: (two heads) manubrium of sternum medial portion of clavicle
	Insertion: mastoid process of temporal bone
	Action: rotates to side opposite of contraction laterally flexes to the contracted side bilaterally flexes the neck
	Blood: occipital artery superior thyroid artery
	Nerve: motor: spinal accessory (XI cranial) sensory: ventral rami of C2,(C3)

Platysma

	Origin: subcutaneous skin over delto-pectoral region
	Insertion: invests in the skin widely over the mandible
	Action: depress mandible and lower lip tenses the skin over the lower neck
	Blood: superficial vessels of the neck
	Nerve: cervical branch of facial nerve (VII cranial)

Anterior Neck

Sternohyoid

	Origin: posterior aspect of manubrium sternal end of clavicle
	Insertion: body of hyoid
	Action: depresses hyoid & larynx acts eccentrically with the suprahyoid muscles to provide them a stable base
	Blood: inferior thyroid artery (primary) superior thyroid artery
	Nerve: upper portions: superior root of ansa cervicalis, C2 lower portions: inferior root of ansa cervicalis, C2,3

Omohyoid

	Attachments: superior belly: hyoid bone (lateral to sternohyoid) inferior belly: superior scapular border (medial to suprascapular notch)
	both bellies meet at the clavicle & are held to the clavicle by a pulley tendon
	Action: depresses hyoid & larynx acts eccentrically with the suprahyoid muscles to provide them a stable base
	Blood: inferior thyroid artery (primary) superior thyroid artery
	Nerve: upper portions: superior root of ansa cervicalis, C2 lower portions: inferior root of ansa cervicalis, C2,3

Sternothyroid

	Origin: posterior aspect of manubrium
	Insertion: oblique line of thyroid cartilage
	Action: depresses hyoid & larynx acts eccentrically with the suprahyoid muscles to provide them a stable base
	Blood: inferior thyroid artery (primary) superior thyroid artery
	Nerve: upper portions: superior root of ansa cervicalis, C2 lower portions: inferior root of ansa cervicalis, C2,3

Thyrohyoid

	Origin: oblique line of thyroid cartilage
	Insertion: body of hyoid
	Action: depresses hyoid may assist in larynx elevation
	Blood: inferior thyroid artery (primary) superior thyroid artery
	Nerve: upper portions: superior root of ansa cervicalis, C2 lower portions: inferior root of ansa cervicalis, C2,3

Stylohyoid

	Origin: styloid process of temporal bone
	Insertion: lateral margin of hyoid (near greater horn)
	Action: pulls the hyoid superiorly & posteriorly during swallowing fixes the hyoid bone for infrahyoid action
	Blood: facial & occipital artery
	Nerve: facial nerve (VII cranial)

Digastric

	Attachments: post belly: mastoid process of temporal bone anterior belly: digastric fossa of internal mandible
	both bellies meet and attach at the lateral aspect of body of hyoid by a pulley tendon
	Action: open mouth by depressing mandible fixes hyoid bone for infrahyoid action
	Blood: branches of the external carotid
	Nerve: posterior belly: facial nerve (VII cranial) anterior belly: mylohyoid nerve

Mylohyoid

	Origin: inner surface of mandible off the mylohyoid line
	Insertion: body of hyoid along midline at mylohyoid raphe
	Action: elevates the hyoid bone raises floor of mouth (for swallowing) depresses mandible when hyoid is fixed
	Blood: lingual artery
	Nerve: mylohyoid nerve (branch of mandibular division, V3 cranial)

Geniohyoid

	Origin: inner surface of the mandible off the mental spines
	Insertion: body of hyoid (paired muscles separated by a septum)
	Action: elevates the tongue depress the mandible works with mylohyoid
	Blood: lingual artery
	Nerve: branch from C1 (following hypoglossal nerve)

Epicranial Musculature

Occipitalis (2 bellies)

	Origin: lateral 2/3 of superior nuchal line external occipital protuberance
	Insertion: galea aponeurosis, over the occipital bone
	Action: draws back the scalp to raise the eyebrows and wrinkle the brow
	Blood: occipital artery
	Nerve: posterior auricular branch of facial nerve

Frontalis (2 bellies)

	Origin: galea aponeurosis, anterior to the vertex
	Insertion: skin above the nose and eyes
	Action: draws back the scalp to raise the eyebrows and wrinkle the brow
	Blood: ophthalmic artery
	Nerve: temporal branch of facial nerve

Muscles of Facial Expression

Orbicularis oculi

	Origin: orbital portion: nasal process of frontal bone palpebral portion: palpebral ligament lacrimal portion: lacrimal crest of lacrimal bone
	Insertion: circumferentially around orbit meeting in palpebral raphe
	Action: powerfully closes the eye
	Blood: ophthalmic artery
	Nerve: zygomatic branch of facial nerve

Corrugator supercilii

	Origin: frontal bone just above the nose
	Insertion: skin of the medial portion of the eyebrows
	Action: draws the eyebrows downward and medially
	Blood: ophthalmic artery
	Nerve: zygomatic branch of facial nerve

Orbicularis oris

	Origin: alveolar border of maxilla lateral to midline of mandible
	Insertion: circumferentially around mouth blends with other muscles
	Action: closes the lips protrudes the lips
	Blood: facial artery
	Nerve: buccal branch of facial nerve

Levator labii superioris alaeque nasi

	Origin: frontal process of maxilla
	Insertion: upper lip muscles nasal cartilage
	Action: elevates the upper lip flares the nostrils
	Blood: facial artery
	Nerve: buccal branch of facial nerve

Levator labii superioris

	Origin: medial 1/2 of infraorbital margin
	Insertion: upper lip muscles
	Action: elevates the upper lip
	Blood: facial artery
	Nerve: buccal branch of facial nerve

Zygomaticus minor

	Origin: zygomatic bone, posterior to maxillary-zygomatic suture
	Insertion: skin of the upper lip
	Action: elevates the upper lip
	Blood: facial artery
	Nerve: buccal branch of facial nerve

Zygomaticus major

	Origin: anterior to zygomatic-temporal suture
	Insertion: modiolus (angle of the mouth)
	Action: lifts and draws back the angle(s) of the mouth (as in smiling)
	Blood: facial artery
	Nerve: buccal branch of facial nerve

Risorius (may be absent)

	Origin: parotid fascia
	Insertion: modiolus (angle of the mouth)
	Action: draws the mouth laterally (as in smiling)
	Blood: facial artery
	Nerve: buccal branch of facial nerve

Levator anguli oris

	Origin: maxilla, inferior to infraorbital foramen
	Insertion: modiolus (angle of the mouth)
	Action: lifts the angle(s) of the mouth (as in smiling)
	Blood: facial artery
	Nerve: buccal branch of facial nerve

Buccinator

	Origin: posterior alveolar process of maxilla posterior alveolar process of mandible along the pterygomandibular raphe
	Insertion: modiolus
	Action: compresses the cheek(s)
	Blood: facial artery
	Nerve: buccal branch of facial nerve

Depressor anguli oris

	Origin: along the oblique line of mandible lateral aspect of mental tubercle of the mandible
	Insertion: modiolus
	Action: lowers the angle(s) of the mouth (as in frowning)
	Blood: facial artery
	Nerve: mandibular branch of facial nerve

Depressor labii inferioris

	Origin: mandible, between symphysis and mental foramen along oblique line of the mandible
	Insertion: skin of the lower lip
	Action: draws the lower lip downward and laterally
	Blood: facial artery
	Nerve: mandibular branch of facial nerve

Muscles of Mastication

Masseter

Origin:

	Superficial: zygomatic process of the maxilla inferior border of zygomatic arch
	Intermediate: inner surface of zygomatic arch
	Deep: posterior aspect of inferior border of zygomatic arch

Insertion:

	Superficial: angle of mandible lateral surface of mandibular ramus
	Intermediate: ramus of mandible
	Deep: superior ramus of mandible coronoid process of mandible

Action:

closes the lower jaw (clenches the teeth)
may deviate mandible to opposite side of contraction

Blood: masseteric artery

Nerve: masseteric nerve

Medial pterygoid

	Origin: medial surface of lateral pterygoid plate of the sphenoid palatine bone pterygoid fossa
	Insertion: inner surface of mandibular ramus angle of the mandible
	Action: closes the lower jaw (clenches the teeth) can protrude the mandible in combination with the lateral pterygoid
	Blood: medial pterygoid artery
	Nerve: medial pterygoid nerve

Lateral pterygoid

	Origin: Superior head: lateral surface of the greater wing of the sphenoid Inferior head: lateral surface of the lateral pterygoid plate
	Insert together: neck of the mandibular condyle articular disk of the TMJ
	Action: deviates mandible to side opposite of contraction (during chewing) opens mouth by protruding mandible (inferior head) closes the mandible (superior head)
	Blood: lateral pterygoid artery
	Nerve: lateral pterygoid nerve

Extraocular Musculature

Levator palpebrae superioris

	Origin: inferior aspect of the lesser wing of sphenoid (adjacent to the common annular tendon)
	Insertion: medial and lateral walls of the orbit superior tarsus
	Action: elevates the eyelid
	Blood: branches of ophthalmic artery
	Nerve: oculomotor nerve (III cranial)

Lateral rectus

	Origin: common annular tendon (which comes off the body and lesser wing of sphenoid) margins of the optic canal
	Insert: posterior to the sclerocorneal junction (each muscle inserting along its own directional axis)
	Action: abducts eye
	Blood: branches of ophthalmic artery
	Nerve: abducens nerve (VI cranial)

Medial rectus

	Origin: common annular tendon (which comes off the body and lesser wing of sphenoid) margins of the optic canal
	Insert: posterior to the sclerocorneal junction (each muscle inserting along its own directional axis)
	Action: adducts eye
	Blood: branches of ophthalmic artery
	Nerve: oculomotor nerve (III cranial)

Superior rectus

	Origin: common annular tendon (which comes off the body and lesser wing of sphenoid) margins of the optic canal
	Insert: posterior to the sclerocorneal junction (each muscle inserting along its own directional axis)
	Action: elevates medially rotates adducts the eye
	Blood: branches of ophthalmic artery
	Nerve: oculomotor nerve (III cranial)

Superior rectus

	Origin: common annular tendon (which comes off the body and lesser wing of sphenoid) margins of the optic canal
	Insert: posterior to the sclerocorneal junction (each muscle inserting along its own directional axis)
	Action: elevates medially rotates adducts the eye
	Blood: branches of ophthalmic artery
	Nerve: oculomotor nerve (III cranial)

Inferior rectus

	Origin: common annular tendon (which comes off the body and lesser wing of sphenoid) margins of the optic canal
	Insert: posterior to the sclerocorneal junction (each muscle inserting along its own directional axis)
	Action: depress laterally rotates adducts the eye
	Blood: branches of ophthalmic artery
	Nerve: oculomotor nerve (III cranial)

Superior oblique

	Origin: body of sphenoid
	Insert: upper lateral quadrant of the posterior half of the sclera (via the trochlea, as a pulley)
	Action: depress medially rotates abducts the eye
	Blood: branches of ophthalmic artery
	Nerve: trochlear nerve (IV cranial)

Inferior oblique

	Origin: orbital surface of maxilla
	Insert: lower lateral quadrant of the posterior half of the sclera (via the suspensory ligament, as a pulley)
	Action: elevates laterally rotates abducts the eye
	Blood: branches of ophthalmic artery
	Nerve: oculomotor nerve (III cranial)