Anatomy and Physiology I

Muscles of

Facial Expression,

Mastication, and

Movement of the Head

Instructor: Mary Holman

www.bodyworlds.com

Dr. Gunther von Hagens

Plastination

Characteristics Used to Name Muscles

Directional terms used to describe orientation of muscle fibers to body midline

• Rectus - parallel to midline

• Transverse - perpendicular to midline

• Oblique - diagonal to midline

Characteristics Used to Name Muscles

Size - Relative size of the muscle• Maximus - largest

• Minimus - smallest• Longus - long• Brevis - short• Latissimus - widest• Longissimus - longest• Magnus - large• Major - larger• Minor - smaller• Vastus - great

Characteristics Used to Name MusclesShape - Relative shape of the muscle• Deltoid - triangular

• Trapezius - trapezoid• Serratus - saw-toothed• Rhomboideus - diamond-shaped• Orbicularis - circular• Pectinate - comb-like• Piriformis - pear-shaped• Platys - flat•Quadratus - square

• Gracilis - slender

Characteristics Used to Name Muscles

Action - Principle action of the muscleFlexor - decreases joint angle

Extensor - increases joint angle

Abductor - moves bone away from midline

Adductor - moves bone toward midline

Levator - produces superior movement

Depressor - produces inferior movement

Supinator - Turns palm superiorly or anteriorly

Pronator - Turns palm inferiorly or posteriorly

Sphincter - decreases size of opening

Tensor - makes a body part rigid

Rotator - moves bone around longitudinal axis

Characteristics Used to Name Muscles

Number of Origins

• Biceps - two origins

• Triceps - three origins

• Quadriceps - four origins

Location

• Example - frontalis

Origin and Insertion

• Example - Sternocleidomastoid

Important Terms of Muscle Action

Origin

Insertion

Agonist or Prime mover

Synergist

Antagonist

Muscles of Facial Expression

• Epicranius

Frontalis and Occipitalis

• Orbicularis oculi

• Orbicularis oris

• Buccinator

• Zygomaticus

major and minor

• Platysma

Fig. 9.25a

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Epicranial aponeurosis

Epicranius

Orbicularis oculi

Zygomaticus major

Zygomaticus minor

Buccinator

Orbicularis oris

Platysma

Frontalis

Occipitalis

Muscles of Facial Expression

Origin: Occipital Bone

Insertion: Skin/muscle near eye

Action: Raises eyebrows

Fig. 9.25a

Epicranial aponeurosis

Frontalis

Occipitalis Epicranius

Origin: Maxillary and frontal bones

Insertion: Skin around eye

Action: Closes eye

Fig. 9.25a

Orbicularis oculi

Origin: Zygomatic bone

Insertion: Orbicularis oris

Action:Raises corner of the mouth

Fig. 9.25a

Zygomaticusmajor and minor

minor

major

Origin: Muscles near mouth

Insertion: Skin of lip

Action: Closes/protrudes lips

Fig. 9.25a

Orbicularis oris

Fig. 9.25b

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Buccinator

Origin: Outer surfaces of maxillaand mandible

Insertion: Orbicularis oris

Action:Compresses cheeks in-ward

9.25a

Risorius

Action: Abducts angle of the mouth

Origin:Fascia in upper chest

Insertion:Lower border of mandible

Action:Draws edges of mouth down - pouting

Fig. 9.25a

Platysma

Muscles of Mastication

•Temporalis

• Lateral Pterygoid

• Medial Pterygoid

• Masseter

Temporalis9.25 b

Origin:Temporal bone

Insertion:Coronoid process andanterior ramus of mandible

Action:Elevates mandible

Origin: Sphenoid bone

Insertion:Anterior surface of mandibular condyle

Action: Depresses and protractsmandible and moves it side to side

Fig. 9.25c

Lateral Pterygoid

medial

lateral

Origin:Sphenoid, palatine andmaxillary bones

Insertion:Medial surface of mandible

Action:Elevates mandible andmoves it side to side

Fig. 9.25c

Medial Pterygoid

medial

lateral

Pterygoids

Origin:Lower border of zygo-matic arch

Insertion:Lateral surface of mandible

Action:Elevates mandible

Fig. 9.25a

Masseter

Muscles that Move the Head

• Sternocleidomastoid

• Splenius capitis

• Semispinalis capitis

• Longissimus capitis

• Scalenes

Origin: Anterior surface of the sternum, upper surface of the clavicle

Insertion:Mastoid process of temporal bone

Action:Flexes neck, pulls head to one side, elevates sternum

Fig. 9.25a

Sternocleidomastoid

Fig. 9.26

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Origin: Spinous processesof upper thoracic and lower cervical vertebrae

Insertion: Occipital bone & mastoid process of temporal

Action:Rotates head, bends head to one side, or extends neck

Splenius capitis

Fig. 9.26

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Origin: Processes of upperthoracic and lower cervicalvertebrae

Insertion: Occipital bone

Action: Extends head, bendshead to one side, or rotates head

Semispinalis capitis

Semispinalis capitis cut

Fig. 9.26

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Origin: Upper thoracic and lower cervical vertebrae

Insertion: Mastoid processtemporal bone

Action: Extends and rotates head

Longissimus capitis

Scalenes

First Rib

Second Rib

Origin:Transverse processescervical vertebrae 2-6

Insertion: 1st and 2nd ribs

Action: Flex head,elevate 1st and 2nd rib,Laterally flex head, rotatehead to side

Atlas Axis

Temporalis

Frontalis

Orbicularis oculi

Orbicularis oris

Zygomaticus

Sternocleidomastoid

Occipitalis

Trapezius

Masseter

Risorius

Buccinator

Omohyoid

2 = Frontalis 3 = Temporalis 7 = Orbicularis oculi

8 = Orbicularis oris13 = Sternocleidomastoid

Buccinator

Risorius

Zygomaticus minorZygomaticus major

Trapezius

Pink passion lipstick