Muscle of the Body Muscles of the Head

Muscles of Facial Expression

Muscles of Facial Expression The muscles that promote facial expression lie just deep to the skin.

Muscles of Facial Expression The muscles that promote facial expression lie just deep to the skin. They are thin and variable shape and are fused to other muscles.

Muscles of Facial Expression The muscles that promote facial expression lie just deep to the skin. They are thin and variable shape and are fused to other muscles. They are unusual in that they insert on the skin and not the bone.

Muscles of Facial Expression These muscles are responsible for: Lifting the eye brows Flaring of the nostrils Opening and closing the mouth Muscles of Facial Expression How important are these muscles for our nonverbal communication?

Muscles of Facial Expression Examine the “masked face” of a person with Parkinson’s Disease where the facial muscles are no longer functioning.

Muscles of Facial Expression All the muscles described below are innervated by the Facial Nerve (cranial Nerve VII)

Muscles of Facial Expression Epicranius consists of the frontal and occipital bellies connected by the galena aponeurosis. The frontal belly raises the eye brows wile the occipital belly pulls the scalp posteriorly.

Muscles of Facial Expression

Figure 10. 6 Lateral view of muscles of Epicranius the scalp, face, and neck. Galea Corrugator supercilii Orbicularis oculi Levator labii superioris Zygomaticus minor and major Buccinator Risorius Orbicularis oris Mentalis Depressor labii inferioris Depressor anguli oris Platysma Copyright © 2010 Pearson Education, Inc. aponeurotica Frontal belly Occipital belly Temporalis Masseter Sternocleidomastoid Trapezius Splenius capitis

Muscles of Facial Expression Corrugator supercilii draws the eyebrows together and inferiorly, better known as the frown.

Figure 10. 6 Lateral view of muscles of Epicranius the scalp, face, and neck. Galea Corrugator supercilii Orbicularis oculi Levator labii superioris Zygomaticus minor and major Buccinator Risorius Orbicularis oris Mentalis Depressor labii inferioris Depressor anguli oris Platysma Copyright © 2010 Pearson Education, Inc. aponeurotica Frontal belly Occipital belly Temporalis Masseter Sternocleidomastoid Trapezius Splenius capitis

Muscles of Facial Expression Obicularis oculi is a sphincter muscle of the eyelid and is responsible for closing the eye, squinting and blinking.

Figure 10. 6 Lateral view of muscles of Epicranius the scalp, face, and neck. Galea Corrugator supercilii Orbicularis oculi Levator labii superioris Zygomaticus minor and major Buccinator Risorius Orbicularis oris Mentalis Depressor labii inferioris Depressor anguli oris Platysma Copyright © 2010 Pearson Education, Inc. aponeurotica Frontal belly Occipital belly Temporalis Masseter Sternocleidomastoid Trapezius Splenius capitis

Muscles of Facial Expression Zygomaticus (major and minor) run from the zygomatic bone to the skin and muscles at the corner of the mouth. They are your smiling muscles .

Figure 10. 6 Lateral view of muscles of Epicranius the scalp, face, and neck. Galea Corrugator supercilii Orbicularis oculi Levator labii superioris Zygomaticus minor and major Buccinator Risorius Orbicularis oris Mentalis Depressor labii inferioris Depressor anguli oris Platysma Copyright © 2010 Pearson Education, Inc. aponeurotica Frontal belly Occipital belly Temporalis Masseter Sternocleidomastoid Trapezius Splenius capitis

Muscles of Facial Expression Risorius lies just below the Zygomaticus and inserts on the skin at the angle of the mouth and originates in the fascia along the Masseter muscle. It tenses your lips.

Figure 10. 6 Lateral view of muscles of Epicranius the scalp, face, and neck. Galea Corrugator supercilii Orbicularis oculi Levator labii superioris Zygomaticus minor and major Buccinator Risorius Orbicularis oris Mentalis Depressor labii inferioris Depressor anguli oris Platysma Copyright © 2010 Pearson Education, Inc. aponeurotica Frontal belly Occipital belly Temporalis Masseter Sternocleidomastoid Trapezius Splenius capitis

Muscles of Facial Expression Levator labii superioris originates on the zygomatic bone and margin of the maxilla and inserts on the skin of the upper lip. It raises and furrows the upper lip.

Muscles of Facial Expression Levator labii superioris originates on the zygomatic bone and margin of the maxilla and inserts on the skin of the upper lip. It raises and furrows the upper lip. Depressor labii inferioris originates on the mandible and inserts on the muscles and skin of the lower lip. It draws the lip down (pouting)

Muscles of Facial Expression

Figure 10. 6 Lateral view of muscles of Epicranius the scalp, face, and neck. Galea Corrugator supercilii Orbicularis oculi Levator labii superioris Zygomaticus minor and major Buccinator Risorius Orbicularis oris Mentalis Depressor labii inferioris Depressor anguli oris Platysma Copyright © 2010 Pearson Education, Inc. aponeurotica Frontal belly Occipital belly Temporalis Masseter Sternocleidomastoid Trapezius Splenius capitis

Muscles of Facial Expression Orbicularis oris is primarily a circular muscle and has a complicated origin in the fascia around the mandible and maxilla. It inserts on the angles of the mouth. It protrudes the lips as in whistling.

Muscles of Facial Expression

Muscles of Facial Expression Mentalis is a V shaped muscle at the base of the chin. It helps in protruding the lower lip.

Muscles of Facial Expression Mentalis is a V shaped muscle at the base of the chin. It helps in protruding the lower lip. Buccinator is a thin horizontal muscle and is the primary muscle of the cheek. It inserts on the Obicularis oris and originates on the maxilla and mandible. It compresses the cheek muscles.

Muscles of Facial Expression

Figure 10. 6 Lateral view of muscles of Epicranius the scalp, face, and neck. Galea Corrugator supercilii Orbicularis oculi Levator labii superioris Zygomaticus minor and major Buccinator Risorius Orbicularis oris Mentalis Depressor labii inferioris Depressor anguli oris Platysma Copyright © 2010 Pearson Education, Inc. aponeurotica Frontal belly Occipital belly Temporalis Masseter Sternocleidomastoid Trapezius Splenius capitis

Muscles of Facial Expression Platysma is a thin sheet like neck muscle that tenses the skin of the neck. It originates on the fascia of the chest and inserts on the lower margin of mandible and skin.

Muscles of Facial Expression

Muscles of Mastication & Tongue Movement Four pairs of muscles are involved in mastication. All are innervated by the cranial nerve V.

Muscles of Mastication & Tongue Movement Four pairs of muscles are involved in mastication. All are innervated by the cranial nerve V. The Masseter and Temporalis muscles are prime movers for clenching the jaw. The Pterygoid muscles provide the grinding action.

Muscles of Mastication & Tongue Movement Four pairs of muscles are involved in mastication. All are innervated by the cranial nerve V. The Masseter and Temporalis muscles are prime movers for clenching the jaw. The Pterygoid muscles provide the grinding action. The Tongue composed of intrinsic muscles which provide its range of motion. Extrinsic muscles all innervated by the hypoglossal (cranial nerve XII), move and anchor the tongue.

Muscles of Mastication & Tongue Movement The Masseter covers the lateral part of the mandibular ramus. It originates on the zygomatic bone and inserts on the angle of the ramus of the mandible. It elevates the jaw.

Muscles of Mastication & Tongue Movement The Masseter covers the lateral part of the mandibular ramus. It originates on the zygomatic bone and inserts on the angle of the ramus of the mandible. It closes the jaw. The Temporalis is a large fan shaped muscle that covers the temporal and parietal lobes. It inserts on the coronoid process of the mandible. It closes the jaw.

Muscles of Mastication & Tongue Movement

Figure 10. 7 a Muscles promoting mastication and tongue movements. Temporalis Orbicularis oris Buccinator (a) Masseter

Muscles of Mastication & Tongue Movement The Medial Pterygoid muscles originate on the pterygoid process of the sphenoid bone and insert on the medial surface mandible. It promotes side to side movement of the jaw. The Lateral Pterygoid muscles originate on the pterygoid process of the sphenoid bone and insert on the condyle of the mandible. It promotes side to side movement of the jaw.

Figure 10. 7 b Muscles promoting mastication and tongue movements. Lateral pterygoid Medial pterygoid Masseter pulled away (b)

Muscles of Mastication & Tongue Movement The Genioglossus is an extrinsic muscle of the tongue and forms the bulk of the inferior part of the tongue. Its origin is on the internal surface of the mandible and it inserts on the inferior part of the tongue and hyoid bone.

Muscles of Mastication & Tongue Movement The Genioglossus is an extrinsic muscle of the tongue and forms the bulk of the inferior part of the tongue. Its origin is on the internal surface of the mandible and it inserts on the inferior part of the tongue and hyoid bone. It protracts (stick out) the tongue.

Muscles of Mastication & Tongue Movement

Figure 10. 7 c Muscles promoting mastication and tongue movements. Tongue Styloid process Styloglossus Hyoglossus Stylohyoid Hyoid bone Genioglossus Mandibular symphysis Geniohyoid Thyroid cartilage Thyrohyoid (c)

Muscles of Mastication & Tongue Movement The Hyoglossus is an extrinsic muscle of the tongue. Its origin is on the hyoid bone and it inserts on the inferior lateral part of the tongue. It depresses the tongue.

Muscles of Mastication & Tongue Movement The Hyoglossus is an extrinsic muscle of the tongue. Its origin is on the hyoid bone and it inserts on the inferior lateral part of the tongue. It depresses the tongue. The Styloglossus is an extrinsic muscle that runs superiorly and at a right angle to the Hyoglossus. It retracts (pulls in) the tongue. (Opposite of what muscle? )

Figure 10. 7 c Muscles promoting mastication and tongue movements. Tongue Styloid process Styloglossus Hyoglossus Stylohyoid Hyoid bone Genioglossus Mandibular symphysis Geniohyoid Thyroid cartilage Thyrohyoid (c)