Head and Neck Musculature

Muscle Regions of the Body:

Return to the Muscle Starting Point

Muscle Groups within this Region:

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

Links Related to this Region:

TMJ Tutorial

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:
1. bilaterally extends the head
2. 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:
1. bilaterally extends the head
2. 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

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

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:
1. elevates the ribs for respiration
  if ribs fixed:
2. rotates to side opposite of contraction
3. laterally flexes to the contracted side
4. 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:
1. elevates the ribs for respiration
  if ribs fixed:
2. rotates to side opposite of contraction
3. laterally flexes to the contracted side
4. bilaterally flexes the neck
Blood: ascending cervical artery
Nerve: variable (cervical and brachial plexus)

Attachment A: transverse processes of all cervical vertebrae
Attachment B: 1st rib (behind anterior scalene)
Action:
1. elevates the ribs for respiration
  if ribs fixed:
2. rotates to side opposite of contraction
3. laterally flexes to the contracted side
4. 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:
1. elevates the ribs for respiration
  if ribs fixed:
2. rotates to side opposite of contraction
3. laterally flexes to the contracted side
4. bilaterally flexes the neck
Blood: ascending cervical artery
Nerve: ventral rami C5-C7

Superficial Neck Musculature

Sternocleidomastoid

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

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

Anterior Neck

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

Attachments:
1. superior belly: hyoid bone (lateral to sternohyoid)
2. 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:
1. depresses hyoid & larynx
2. acts eccentrically with the suprahyoid muscles to provide them a stable base
Blood:
1. inferior thyroid artery (primary)
2. superior thyroid artery
Nerve:
1. upper portions: superior root of ansa cervicalis, C2
2. lower portions: inferior root of ansa cervicalis, C2,3

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

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

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

Attachments:
1. post belly: mastoid process of temporal bone
2. 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:
1. open mouth by depressing mandible
2. fixes hyoid bone for infrahyoid action
Blood: branches of the external carotid
Nerve:
1. posterior belly: facial nerve (VII cranial)
2. anterior belly: mylohyoid nerve

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

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

Epicranial Musculature

Occipitalis (2 bellies)

Origin:
1. lateral 2/3 of superior nuchal line
2. 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:
1. orbital portion: nasal process of frontal bone
2. palpebral portion: palpebral ligament
3. 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:
1. alveolar border of maxilla
2. lateral to midline of mandible
Insertion:
1. circumferentially around mouth
2. blends with other muscles
Action:
1. closes the lips
2. protrudes the lips
Blood: facial artery
Nerve: buccal branch of facial nerve

Levator labii superioris alaeque nasi

Origin: frontal process of maxilla
Insertion:
1. upper lip muscles
2. nasal cartilage
Action:
1. elevates the upper lip
2. 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

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

Depressor anguli oris

Origin:
1. along the oblique line of mandible
2. 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:
1. mandible, between symphysis and mental foramen
2. 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

Origin:
- Superficial:
  1. zygomatic process of the maxilla
  2. inferior border of zygomatic arch
- Intermediate: inner surface of zygomatic arch
- Deep: posterior aspect of inferior border of zygomatic arch
Insertion:
- Superficial:
  1. angle of mandible
  2. lateral surface of mandibular ramus
- Intermediate: ramus of mandible
- Deep:
  1. superior ramus of mandible
  2. coronoid process of mandible
Action:
1. closes the lower jaw (clenches the teeth)
2. may deviate mandible to opposite side of contraction
Blood: masseteric artery
Nerve: masseteric nerve

Medial pterygoid

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

Lateral pterygoid

Origin:
1. Superior head: lateral surface of the greater wing of the sphenoid
2. Inferior head: lateral surface of the lateral pterygoid plate
Insert together:
1. neck of the mandibular condyle
2. articular disk of the TMJ
Action:
1. deviates mandible to side opposite of contraction (during chewing)
2. opens mouth by protruding mandible (inferior head)
3. 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:
1. medial and lateral walls of the orbit
2. superior tarsus
Action: elevates the eyelid
Blood: branches of ophthalmic artery
Nerve: oculomotor nerve (III cranial)

Origin:
1. common annular tendon (which comes off the body and lesser wing of sphenoid)
2. 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)

Origin:
1. common annular tendon (which comes off the body and lesser wing of sphenoid)
2. 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:
1. common annular tendon (which comes off the body and lesser wing of sphenoid)
2. margins of the optic canal
Insert: posterior to the sclerocorneal junction (each muscle inserting along its own directional axis)
Action:
1. elevates
2. medially rotates
3. adducts the eye
Blood: branches of ophthalmic artery
Nerve: oculomotor nerve (III cranial)

Superior rectus

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

Inferior rectus

Origin:
1. common annular tendon (which comes off the body and lesser wing of sphenoid)
2. margins of the optic canal
Insert: posterior to the sclerocorneal junction (each muscle inserting along its own directional axis)
Action:
1. depress
2. laterally rotates
3. 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:
1. depress
2. medially rotates
3. 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:
1. elevates
2. laterally rotates
3. abducts the eye
Blood: branches of ophthalmic artery
Nerve: oculomotor nerve (III cranial)

Laryngeal Musculature

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© 1998 by Darryl Hosford, all rights reserved.