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 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 Muscles of Facial Expression Frontalis Epicranial aponeurosis Epicranius Occipitalis Orbicularis oculi Zygomaticus major Zygomaticus minor Orbicularis oris Buccinator Platysma Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Occipitalis Epicranius Epicranial aponeurosis Frontalis Origin: Occipital Bone Insertion: Skin/muscle near eye Action: Raises eyebrows Fig. 9.25a Orbicularis oculi Origin: Maxillary and frontal bones Insertion: Skin around eye Action: Closes eye Fig. 9.25a Zygomaticus major and minor Origin: Zygomatic bone Insertion: Orbicularis oris major minor Fig. 9.25a Action: Raises corner of the mouth Orbicularis oris Origin: Muscles near mouth Insertion: Skin of lip Action: Closes/protrudes lips Fig. 9.25a Fig. 9.25b Buccinator Origin: Outer surfaces of maxilla and mandible Insertion: Orbicularis oris Action: Compresses cheeks inward 9.25a Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Risorius Action: Abducts angle of the mouth Platysma Origin: Fascia in upper chest Insertion: Lower border of mandible Action: Draws edges of mouth down - pouting Fig. 9.25a Muscles of Mastication •Temporalis • Lateral Pterygoid • Medial Pterygoid • Masseter 9.25 b Temporalis Origin: Temporal bone Insertion: Coronoid process and anterior ramus of mandible Action: Elevates mandible Fig. 9.25c Lateral Pterygoid lateral medial Origin: Sphenoid bone Insertion: Anterior surface of mandibular condyle Action: Depresses and protracts mandible and moves it side to side Fig. 9.25c Medial Pterygoid lateral medial Origin: Sphenoid, palatine and maxillary bones Insertion: Medial surface of mandible Action: Elevates mandible and moves it side to side Pterygoids Masseter Origin: Lower border of zygomatic arch Insertion: Lateral surface of mandible Action: Elevates mandible Fig. 9.25a Muscles that Move the Head • Sternocleidomastoid • Splenius capitis • Semispinalis capitis • Longissimus capitis • Scalenes Sternocleidomastoid Origin: Anterior surface of the sternum, upper surface of the clavicle Insertion: Mastoid process of temporal bone Action: Fig. 9.25a Flexes neck, pulls head to one side, elevates sternum Fig. 9.26 Splenius capitis 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 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Fig. 9.26 Semispinalis capitis Semispinalis capitis cut Origin: Processes of upper thoracic and lower cervical vertebrae Insertion: Occipital bone Action: Extends head, bends head to one side, or rotates head Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Fig. 9.26 Longissimus capitis Origin: Upper thoracic and lower cervical vertebrae Insertion: Mastoid process temporal bone Action: Extends and rotates head Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Scalenes Atlas Axis Origin: Transverse processes cervical vertebrae 2-6 Insertion: 1st and 2nd ribs Action: Flex head, First Rib Second Rib elevate 1st and 2nd rib, Laterally flex head, rotate head to side Frontalis Temporalis Orbicularis oculi Occipitalis Orbicularis oris Masseter Zygomaticus Buccinator Risorius Trapezius Omohyoid Sternocleidomastoid 2 = Frontalis 3 = Temporalis 7 = Orbicularis oculi 8 = Orbicularis oris 13 = Sternocleidomastoid Zygomaticus minor Zygomaticus major Pink passion lipstick Trapezius Buccinator Risorius