Anatomy and Physiology I Muscles of Facial Expression, Mastication, and Movement of the Head Instructor: Mary Holman

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 Muscles Shape - 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 muscle Flexor - 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 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 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 Zygomaticus major and minor minor major

Origin: Muscles near mouth Insertion: Skin of lip Action: Closes/protrudes lips Fig. 9.25a Orbicularis oris

Fig. 9.25b Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Buccinator Origin: Outer surfaces of maxilla and 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

Temporalis 9.25 b Origin: Temporal bone Insertion: Coronoid process and anterior ramus of mandible Action: Elevates mandible

Origin: Sphenoid bone Insertion: Anterior surface of mandibular condyle Action: Depresses and protracts mandible and moves it side to side Fig. 9.25c Lateral Pterygoid medial lateral

Origin: Sphenoid, palatine and maxillary bones Insertion: Medial surface of mandible Action: Elevates mandible and moves 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 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Origin: Spinous processes of 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 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Origin: Processes of upper thoracic and lower cervical vertebrae Insertion: Occipital bone Action: Extends head, bends head to one side, or rotates head Semispinalis capitis Semispinalis capitis cut

Fig Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Origin: Upper thoracic and lower cervical vertebrae Insertion: Mastoid process temporal bone Action: Extends and rotates head Longissimus capitis

Scalenes First Rib Second Rib Origin: Transverse processes cervical vertebrae 2-6 Insertion: 1st and 2nd ribs Action: Flex head, elevate 1st and 2nd rib, Laterally flex head, rotate head to side AtlasAxis

Temporalis Frontalis Orbicularis oculi Orbicularis oris Zygomaticus Sternocleidomastoid Occipitalis Trapezius Masseter Risorius Buccinator Omohyoid

2 = Frontalis 3 = Temporalis 7 = Orbicularis oculi 8 = Orbicularis oris 13 = Sternocleidomastoid Buccinator Risorius Zygomaticus minor Zygomaticus major Trapezius Pink passion lipstick