ANAT 392 - Lecture 1: Facial Muscles and Nerves

Flashcards covering the origins, insertions, innervations, and functions of facial muscles, as well as details on CN VII (Facial Nerve) and CN V (Trigeminal Nerve) from ANAT 392.

Orbicularis oculi (3 fibers)

The three fibers of this muscle are lacrimal, palpebral, and orbital.

Orbicularis oculi lacrimal fibers (Origin)

Lacrimal bone.

Orbicularis oculi palpebral fibers (Origin)

Maxilla.

Orbicularis oculi orbital fibers (Origin)

Maxilla.

Orbicularis oculi lacrimal fibers (Insertion)

Skin of the orbital reigon.

Orbicularis oculi palpebral fibers (Insertion)

Eyelids.

Orbicularis oculi orbital fibers (Insertion)

Skin of orbital region.

Orbicularis oculi (Innervation)

CN VII, facial nerve.

Orbicularis oculi lacrimal fibers (Function)

Opens nasolacrimal duct.

Orbicularis oculi palpebral fibers (Function)

Soft closure of eyes.

Orbicularis oculi orbital fibers (Function)

Squeezing eyes shut.

Orbicularis oculi (General Origin)

Frontal bone and maxilla.

Orbicularis oculi (General Insertion)

Skin around eye.

Corrugator supercilii (Origin)

Superciliary arch of frontal bone.

Corrugator supercilii (Insertion)

Medial end of skin under eyebrow on frontal bone.

Corrugator supercilii (Innervation)

CN VII, facial nerve.

Corrugator supercilii (Function)

Frowning, creating vertical lines between eyebrows.

Levator labi superioris alaque nasi (Origin)

Maxilla.

Levator labi superioris alaque nasi (Insertion)

Nostrils (medial fibers) and upper lip (lateral fibers).

Levator labi superioris alaque nasi (Innervation)

CN VII, facial nerve.

Levator labi superioris alaque nasi (Function)

Elevates upper lip and nostrils.

Procerus (Origin)

Nasal bone.

Procerus (Insertion)

Skin of forehead between eyebrows.

Procerus (Innervation)

CN VII, facial nerve.

Procerus (Function)

Horizontal wrinkles on nasal bridge, scrunching of nose.

Nasalis (Origin)

Maxilla.

Nasalis (Insertion)

Bridge of nose, contralateral muscles.

Nasalis (Innervation)

CN VII, facial nerve.

Nasalis (Function)

Compresses nose, widens nostrils.

Orbicularis oris (Origin)

Maxilla and mandible.

Orbicularis oris (Insertion)

Skin around lips.

Orbicularis oris (Innervation)

CN VII, facial nerve.

Orbicularis oris (Function)

Closes mouth and protrudes lips.

Zygomaticus major (Origin)

Zygomatic bone.

Zygomaticus minor (Origin)

Zygomatic bone.

Zygomaticus major (Insertion)

Corner of the mouth.

Zygomaticus minor (Insertion)

Upper lip.

Zygomaticus muscles (Innervation)

CN VII, facial nerve.

Zygomaticus major (Function)

Widens mouth for smiling.

Zygomaticus minor (Function)

Elevates upper lip.

Risorius (Origin)

Deep fascia of face.

Risorius (Insertion)

Corner of mouth.

Risorius (Innervation)

CN VII, facial nerve.

Risorius (Function)

Widen mouth (smiling).

Mentalis (Origin)

Mandible.

Mentalis (Insertion)

Lower lip.

Mentalis (Innervation)

CN VII, facial nerve.

Mentalis (Function)

Wrinkles chin.

Occipitofrontalis (Origin)

Frontal bone.

Occipitofrontalis (Insertion)

Occipital bone.

Occipitofrontalis (Innervation)

CN VII, facial nerve.

Occipitofrontalis (Function)

Raises eyebrows, wrinkles forehead, and moves scalp.

Depressor anguli oris (Origin)

Mandible.

Depressor anguli oris (Insertion)

Corner of mouth.

Depressor anguli oris (Innervation)

CN VII, facial nerve.

Depressor labi inferioris (Origin)

Anterior part of oblique line of mandible.

Depressor labi inferioris (Insertion)

Lower lip.

Depressor labi inferioris (Innervation)

CN VII, facial nerve.

Depressor labi inferioris (Function)

Draws lower lip down and laterally.

Buccinator (Origin)

Mandible and maxilla.

Buccinator (Insertion)

Mouth.

Buccinator (Innervation)

CN VII, facial nerve.

Buccinator (Function)

Pushes food between teeth.

Platysma (Origin)

Thoracic fascia.

Platysma (Insertion)

Facial fascia/lower lip.

Platysma (Innervation)

CN VII, facial nerve.

Platysma (Function)

Increases tension of the neck (used while shaving).

Border of the head and neck

Outlined by the midline of mandible, mastoid process, and external occipital protuberance.

CN VII (Fiber Types)

Mixed nerve containing three types of fibers: motor, sensory, and parasympathetic.

CN VII (Pathway)

Brainstem -> internal acoustic foramen (splits into 3 fibers) -> stylomastoid foramen (motor fibers only) -> parotid gland (no innervation) -> splits 5 ways.

CN VII (5 Branches)

Temporal, zygomatic, buccal, marginal mandibular, and cervical.

Spastic paralysis

Muscles contract and do not follow orders due to UMN lesion; only affects the lower half of the face on the contralateral side.

Flaccid paralysis

Muscle tone is lost and orders are not followed due to LMN lesion; affects the entire half of the face on the ipsilateral side.

Bell's Palsy (Cause)

Inflammation of the parotid gland.

Bell's Palsy (Symptoms)

Drooping eyelids, deviation of mouth, crocodile tears, and flaccid paralysis ipsilaterally.

CN V (Trigeminal Nerve) Function

General sensory innervation of the face.

CN V (3 Branches)

Ophthalmic, maxillary, and mandibular.

Supraorbital nerve

The terminal branch of the ophthalmic branch of CN V.

Infraorbital nerve

The terminal branch of the maxillary branch of CN V.

Mental nerve and Auriculotemporal nerve

The terminal branches of the mandibular branch of CN V.

Mandibular branch of CN V (Motor Component)

The only division of the trigeminal nerve that has a motor component, specifically for the muscles of mastication.