Muscles of the Head & Neck/ Muscles of Facial Expression & Mastication
Intrinsic Muscles of the Tongue
- Anatomists consider intrinsic tongue muscles to be inseparable - not treated as separate muscles - Four sets: named by orientation: 1. Superior longitudinal 2. Transverse 3. Vertical 4. Inferior longitudinal
Trapezius Muscle
- Covers the lateral and posterior surfaces of the neck - Broad and flat triangular muscle
Muscle: Definition
- Each muscle has two ends that attach to soft tissue and bony structures of the body to move - Categorized according to their role in movement
Sternocleidomastoid Muscle: Innervation
- Eleventh Cranial nerve - XI (accessory nerve)
Corrugator Supercilii: Action
- Frowning - It produces vertical ridges above the bridge of the nose when frowning by drawing the eyebrows downwards and inwards
Extrinsic Muscles of the Tongue
- Origins: All different outside the tongue - Insertions: All inside the tongue: 1. Genioglossus 2. Styloglossus 3. Hyoglossus *Palatoglossus part of the soft palate but anatomist include it in this area - Inervation: 12th Cranial Nerve or Hypoglossal nerve
Muscles of Facial Expression: Facts
- Smiling take 17 muscles to use, while frowning = 43 - Paired muscles (R&L)
Epicranial Muscle: Action
- The frontal bellies raise the eyebrows and the skin over the root of the nose - Used in movements such as: 1. glancing upwards 2. expressions of surprise & fright - Acting from below the frontal parts also draw the scalp forwards to produce wrinkles on the forehead
Muscle of Mastication: General Information
1. All chewing muscles: - Are developed from the first branchial arch - Are inverted by Cranial Nerve V (the trigeminal nerve) - Recieve their blood suppy from the maxillary artery (is a branch of the external carotid artery)
Inferior Head of Lateral Pterygoid: Actions
1. Bilaterally: - Protrudes and depress mandible 2. Unilaterally - lateral excursion: - Deviates to opposite side
Superior Head of Lateral Pterygoid: Insertion
1. Capsule and disk of TMJ 2. Neck of condyle
Muscles of Head & Neck: 7 Main Groups
1. Cervical Muscles 2. Muscles of Facial Expressions 3. Muscles of Mastication 4. Hyoid Muscles 5. Muscles of the tongue 6. Muscle of the soft palate 7. Muscles of the pharynx
Epicranial Muscle: Origin
1. Frontal belly: epicranial aponeurosis - the area where the parietal and occipital bones meet 2. Occipital belly: occipital and temporal bone
Epicranial Muscle: Insertion
1. Frontal belly: eyebrow and root of nose 2. Occipital belly: epicranial aponeurosis
Muscles of the Tongue: Overview
1. Grouped according to whether they are intrinsic or extrinsic 2. Consists of 2 symmetrical halves divided from each other by the median septum 3. Depression it forms is called the median lingual sulcus
Platysma Muscle 3 Parts
1. Labialis 2. Mandibularis 3. Modiolaris
Eye Region Muscle(s)
1. Orbicularis Oculi muscle 2. Corrugator supercilii muscle
Mouth Region Muscle(s)
1. Orbicularis Oris 2. Buccinator 3. Risorius 4. Zygomaticus Major 5. Zygomaticus Minor 6. Levator labii superioris 7. Levator labii superioris alaeque nasi 8. Levator anguli oris 9. Depressor anguli oris 10 Depressor labii inferioris 11. Mentalis 12. Platysma
Muscles of the Soft Palate: Names/Types
1. Palatoglossus 2. Palatopharyngeus 3. Levator veli palatini 4. Tensor veli palatini 5. Muscles of the uvula
Muscles of Facial Expression: 3 Regions
1. Scalp 2. Eye 3. Mouth
Masseter: Two heads
1. Superficial 2. Deep
Medial Pterygoid: 2 Heads
1. Superior (Superficial) 2. Inferior (Deep)
Lateral Pterygoid: 2 Heads
1. Superior (upper) 2. Inferior (lower)
Trapezius Muscle: Innervation
11th cranial nerve (accessory nerve) & the 3rd and 4th cervical nerves
Muscle of Mastication
4 pairs of muscles move the mandible: 1. Masseters 2. Medial Pterygoids 3. Lateral Pterygoids 4. Temporalis Muscles ** Buccinators sometimes included/ sometimes termed an accessory muscle of mastication/ more often considered a muscle of facial expression
Muscles of Facial Expression: Innervation
7th Cranial Nerve or facial nerve on both sides
Median Septum of tongue
A deep fibrous structure in the midline of the tongue
Levator Labii Superioris Alaeque Nasi: Insertion
Ala of nose and upper lip
Superior & Inferior Head of Medial Pterygoid: Insertion
Angle of mandible on medial side
Depressor Anguli Oris: Insertion
Angle of mouth
Levator Anguli Oris: Insertion
Angle of mouth
Orbicularis Oris: Insertion
Angle of mouth
Risorius: Insertion
Angle of mouth
Zygomaticus Major: Insertion
Angle of mouth
Buccinator: Insertion
Angle of the mouth ***Orbicularis oris muscle
Superior Head of Lateral Pterygoid: Actions
Bilaterally: - Power stroke - Guide condyle back to centric relation after opening
Mentalis: Insertion
Chin
Platysma: Origin
Clavicle and shoulder
Orbicularis Oculi: Action
Closing eyelid
Temporalis Muscle: Insertion
Coronoid process of mandible and anterior border of ramus
Muscles of Head & Neck: Division
Divided by function
Superficial & Deep Head of Masseter: Action
Elevate (close) mandible
Temporalis Muscle: Action
Elevate and retrude mandible ** Anterior fibers = elevate ** Posterior fibers = retrude
Orbicularis Oris: Origin
Encircles mouth
Scalp Region Muscle(s)
Epicranial Muscle
Trapezius Muscle: Origin
External surface of the occipital bone
Corrugator Supercilii: Insertion
Eyebrow
Risorius: Origin
Fascia superficial to masseter muscle
Buccinator
Forms the anterior portion of the cheeks and the lateral wall of the oral cavity
Corrugator Supercilii: Origin
Frontal bone
Depressor Anguli Oris: Action
Frowning
Superior Head of Lateral Pterygoid: Origin
Greater wing of sphenoid bone
Orbicularis Oris: Action
Has 4 distinctive movements: 1. Pressing together- closing the lips 2. Tightening and thinning- pursing the lips 3. Rolling inward between the teeth- grimacing 4. Thrusting outward- pouting and kissing
Deep Head of Masseter: Origin
Inferior border of posterior 1/3 of zygomatic arch and entire medial surface of zygomatic arch
Superficial head of Masseter: Origin
Inferior border of the anterior 2/3 of zygomatic arch
Muscles of Facial Expression: Insertion
Insert on the dermis of the skin tissue
Superficial & Deep Head of Masseter: Insertion
Into the ramus and angle of the mandible
Muscle: Origin
Is the end of the muscle that is attached to the least movable structure
Muscle: Insertion
Is the other end of the muscle and is attached to the more movable structure
Orbicularis Oculi: Insertion
Lateral region of eye, some encircle eye
Inferior Head of Lateral Pterygoid: Origin
Lateral side of lateral pterygoid plate
Trapezius Muscle: Insertion
Lateral third of the clavicle and portions of the scapula
Trapezius Muscle: Action
Lift the clavicle and portions of the scapula = shrugged shoulders
Depressor Labii Inferioris: Insertion
Lower lip
Depressor Labii Inferioris: Action
Lowering lower lip
Inferior Head of Medial Pterygoid: Origin
MEdial side of lateral pterygoid plate and pterygoid fossa
Depressor Anguli Oris: Origin
Mandible
Depressor Labii Inferioris: Origin
Mandible
Mentalis: Origin
Mandible
Platysma: Insertion
Mandible and muscles of mouth
Muscles of the Soft Palate: Innervation
Mandibular division of the 5th cranial or trigeninal nerve
Levator Anguli Oris: Origin
Maxilla
Levator Labii Superioris Alaeque Nasi: Origin
Maxilla
Levator Labii Superioris: Origin
Maxilla
Buccinator: Origin
Maxilla, mandible, and pterygomandibular raphe *Buccal aveolar bone of maxillary & mandibular molars * Pterygomandibular raphe = fibrous band extending from pterygoid hamulus to posterior part of mylohyloid line
Superior Head of Medial Pterygoid: Origin
Maxillary tuberosity
Sternocleidomastoid Muscle: Origin
Medial portion of the clavicle and the sternum's superior and lateral surfaces
Sternocleidomastoid Muscle: Action
Movement of head and neck bend and rotation
Inferior Head of Lateral Pterygoid: Insertion
Neck of condyle
Orbicularis Oculi: Origin
Orbital rim, frontal and maxillary bones
Muscles of Facial Expression: Orgin
Originate from the surface of the skull bone (rarely fascia)
Sternocleidomastoid Muscle: Insertion
Posteriorly and superiorly to insert on the mastoid process of the temporal bone
Buccinator: Action
Pulls the angle of the mouth laterally and shortens the cheek both vertically and horizontally: 1. Food position 2. Infants suckling 3. Helps to expel air through pursed lips, blowpipes, or wind instruments ** has been called the "trumpet muscle" *Pulls corner of mouth posteriorly *Pushes food onto occlusal table
Mentalis: Action
Raising chin and protruding lower lip
Platysma: Action
Raising neck skin and grimacing
Levator Labii Superioris: Action
Raising upper lip
Zygomaticus Minor: Action
Raising upper lip (assisting in smile)
Levator Labii Superioris Alaeque Nasi: Action
Raising upper lip and dilating nostrils in a sneer
Epicranial Muscle: Location
Scalp Region
Zygomaticus Major: Action
Smiling
Levator Anguli Oris: Action
Smiling (in combo with the zygomaticus major muscle)
Risorius: Action
Stretching lip (to produce more of a grimace)
Temporalis Muscle: Origin
Temporal fossa and fascia
Cervical Muscles
Two muscles for us to consider that are both superficial and palpated on the neck 1. Sternocleidomastoid muscle 2. Trapezius muscle
Levator Labii Superioris: Insertion
Upper lip
Zygomaticus Minor: Insertion
Upper lip
Superior & Inferior Head of Medial Pterygoid: Action
With masseter, forms sling around mandible and works with mandible to elevate it *Masseter attaches to lateral surface * Medial pterygoid attaches to medial surface
Zygomaticus Major: Origin
Zygomatic bone
Zygomaticus Minor: Origin
Zygomatic bone
Sternocleidomastoid Muscle (SCM)
the SCM divides the neck region into anterior and posterior cervical triangles