Head and Neck Muscles - Module 4

Origin of a muscle usually attaches to

The least movable bony structure

Insertion of a muscle is usually

The most movable part

Name of a muscle is usually

Origin + insertion

2 cervical muscles

1. Sternocleidomastoid (SCM)

2. Trapezius

Trapezius

4 muscles of mastication

Temporalis, masseter, medial pterygoid, lateral pterygoid

SCM origin

Medial end of clavical

SCM insertion

Mastoid process behind the ear

SCM action

Tilts/rotates the head

Trapezius origin

Occipital bone

Trapezius insertion

Lateral 1/3 of clavical

Trapezius action

Shrug shoulders

Trapezius can refer pain to what?

TMJ

Muscles of facial expression originate from what and insert in what?

Originate from the surface of the skull and insert into the dermis

From where is the blood supplied for the muscles of facial expression?

Facial artery, a branch of the external carotid artery

Epicranial muscle action

Raises eyebrow and scalp

Obicularis oculi encircles

eye

Corrugator supercilii action

Wrinkles eyebrows

Obicularis oris encircles

Mouth

Obicularis oris action

Purses lips

Buccinator forms…

Anterior portion of cheek and lateral wall of buccal region

Buccinator is NOT a

Muscle of mastication

Muscles associated with smiling

Risorius, zygomaticus major + minor, levator anguli oris

What stabilizes the hyoid bone?

infrahyoid muscles

What forms the floor of the mouth?

Mylohyoid muscle

Masseter is the…

Strongest muscle of mastication

2 heads of the masseter

Superficial and deep

Masseter origin

Zygomatic arch

Masseter insertion

At the mandible

Masseter action

Elevate the mandible

Temporalis origin

Entire temporal fossa

Temporalis insertion

Coronoid process

Temporalis action

Elevate the mandible

Medial pterygoid is the…

Deepest muscle of mastication

2 heads of medial pterygoid

Superficial and deep

Does temporalis have 2 heads

No

Medial pterygoid is similar to the masseter muscle, but

Weaker

Medial pterygoid muscle action

Elevates and protrudes the mandible

Lateral pterygoid origin

Sphenoid bone

Lateral pterygoid insertion

Mandibular condyle

Lateral pterygoid action if both muscles engaged

Up, down, protrude

Lateral pterygoid action if one muscle is engaged

Side to side

Why are the muscles of mastication important to dental hygiene?

All 4 can refer pain to the TMJ

Hyoid muscles are divided into what 2 groups?

Suprahyoid and infrahyoid

2 primary actions of the suprahyoid muscles

Swallowing, opening mandible

Infrahyoid muscles action

Depresses hyoid bone, helps to open mouth

Muscles of the tongue are divided into…

Intrinsic and extrinsic

Median septum

Separates the sides of the tongue

Extrinsic muscles of the tongue originate and insert where?

Originate outside of the tongue, insert inside of the tongue

4 pairs of intrinsic muscles of the tongue

Superior longitudinal, transverse, vertical, inferior longitudinal

4 pairs of extrinsic muscles of the tongue

Genioglossus, styloglossus, palatoglossus, hyoglossus

Genioglossus action

Sticks out the tongue

Muscles of the pharynx actions

Speaking, swallowing, inner ear function

Stylopharyngeus action

Elevates and widens pharynx

Muscles of the soft palate include…

Palatoglossus, palatopharyngeus, levator veli palatini, tenor veli palatine, muscle of the uvula