Head and Neck Musculature

Muscle Regions of the Body:

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

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

 

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:
  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:
  
  
  
  
  
  if transverse process fixed:
  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)

Middle scalene

• Attachment A: transverse processes of all cervical vertebrae
• Attachment B: 1st rib (behind anterior scalene)
• Action:
  
  
  
  
  
  if transverse process fixed:
  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:
  
  
  
  
  
  if transverse process fixed:
  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)

Platysma

• 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

 

Sternohyoid

• 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

Omohyoid

• 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

Sternothyroid

• 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

Thyrohyoid

• 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

Stylohyoid

• 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)

Digastric

• 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

Mylohyoid

• 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)

Geniohyoid

• 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

Buccinator

• 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

 

Masseter

• 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)

Lateral 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: abducts eye
• Blood: branches of ophthalmic artery
• Nerve: abducens nerve (VI cranial)

Medial 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: 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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