The muscles of the head and neck

Name of muscle

Position

Attachments

Action/s

(front-ta-lis)

Extends over the forehead

Attaches to the skin of the eyebrows and the frontal bone at the hairline

Wrinkles the forehead and raises the eyebrows

Used when expressing surprise

Occipitalis (ok-sip-it-ta-lis)

Base/back of skull

Attached to the occipital bone and the skin of the scalp

Moves the scalp backwards

Is united to the frontalis muscle by a broad tendon called the epicranial aponeurosis which covers the skull like a cap

Temporalis (tem-po-ra-lis)

Fan-shaped muscle situated on the side of the skull above and in front of the ear

Attaches to the temporal bone and to the upper part of the mandible

Raises the lower jaw when chewing

Muscle becomes tightened with a tension headache

Orbicularis oculi (or-bik-you-la-ris ock-you-ly)

Circular muscle surrounding the eye

Attached to the bones at the outer edge and the skin of the upper and lower eyelids at the inner edge

Closes the eye

Used when blinking or winking It also compresses the lacrimal gland, aiding the flow of tears

The muscles of the head and neck 121

Name of muscle

Position

Attachments

Action/s

Key facts

Orbicularis oris (or-bik-you-la-ris or-ris)

Circular muscle that surrounds the mouth

Its fibres attach to the maxilla, mandible, the lips and the buccinator muscle

Closes the mouth

Used when shaping the lips for speech and when kissing

It also contracts the lips when tense

Corrugator (kor-u-gay-tor)

Located in between the eyebrows

Attached to the frontalis muscle and the inner edge of the eyebrow

Brings the eyebrows together

Used when frowning

Procerus

(pro-ser-rus)

Located in between the eyebrows

Attached to the nasal bones and the frontalis muscle

Draws the eyebrows inwards

Creates a puzzled expression

Nasalis (nay-sa-lis)

Located at sides of the nose

Attached to the maxillae bones and the nostrils

Dilates and compresses the nostrils

Used when blowing the nose

Zygomatic major and minor/ zygomaticus (zi-go-mat-ik-us)

Lies in the cheek

Extends from the zygomatic bone to the angle of the mouth

Draws the angle of the mouth upward and laterally

Used when laughing or smiling

Levator labii superioris (le-vay-tor lay-be-eye soo-pee-ri-o-ris)

Above the lip, located towards the inner cheek beside the nose

Extends from the upper jaw to the skin of the corners of the mouth and the upper lip

Raises the upper lip and the corner of the mouth

Used to create a snarling expression

Levator anguli oris (le-vay-tor ang-you-lie o-ris)

Above the lip, located at an angle above the side of the mouth

Extends from the maxilla (upper jaw) to the angle of the mouth

Raises the corner of the mouth

Used when smiling, is also known as the caninus (kay-ni-nus) as its contraction can result in the teeth, especially the canine tooth, becoming visible

Depressor anguli oris (dee-pres-or ang-you-lie o-ris)

Side of chin extending down at an angle from the side of mouth

Extends from the mandible (lower jaw) to the angle of the mouth

Draws the corners of the mouth downwards

Used when expressing sadness or uncertainty

Depressor labii inferioris

(dee-pres-or lay-be-eye in-fee-ri-o-ris)

Side of chin, extending down from lower lip

Extends from the mandible to the angle of the mouth

Pulls the lower lip downwards

Used when expressing sorrow, doubt or irony

Risorius (ri-sor-ri-us)

Triangular-shaped muscle lying horizontally on the cheek, joining at the corners of the mouth (lies above the buccinator)

Attached to the zygomatic bone at one end and the skin of the corner of the mouth at the other

Pulls the corner of the mouth sideways and outwards

Used when grinning

(Continued )

Name of muscle

Position

Attachments

Action/s

Key facts

Buccinator (buk-sin-a-tor)

Main muscle of the cheek

Attached to the maxilla and mandible and the muscles of the lips

Compresses the cheeks when sucking or blowing

Used when blowing a balloon or blowing a trumpet

Helps hold food in contact with the teeth when chewing

Mentalis (men-ta-lis)

Radiates from the lower lip over the centre of the chin

Attached to the mandible and the skin of the lower lip

Elevates the lower lip and wrinkles the skin of the chin

Used when expressing displeasure and when pouting

Masseter (ma-sa-ter)

Thick, flattened muscle at sides of cheek/jaw

Extends from maxilla and zygomatic bone to the mandible

Raises the jaw and exerts pressure on the teeth when chewing

Main muscle of mastication

Can be felt just in front of the ear when the teeth are clenched

Lateral pterygoids (lat-er-al ter-i-goyds)

Outer part of cheeks

Extends from the sphenoid bone to the mandible and temporomandibular joint

Opens the jaw and moves mandible when chewing

Tension in these muscles may be associated with dysfunction of the temporomandibular joint (TMJ syndrome)

Medial pterygoids (mee-dee-al ter-i-goyd)

Outer part of cheeks

Extends from the sphenoid bone to the internal surface of the mandible

Closes the jaw and moves the mandible when chewing

Tension in these muscles may be associated with dysfunction of the temporomandibular joint (TMJ syndrome)

Sternocleidomastoid (ster-no-kli-do-

mas-toyd)

Long muscle that lies obliquely across each side of the neck

Extends upwards from the sternum and clavicle at one end to the mastoid process (back of the ear)

When working together they flex the neck (pull the chin down towards the chest) and when working individually, they rotate the head to the opposite side

Spasm of the sternomastoid muscle results in a condition known as torticollis or wryneck Sternomastoid is the only muscle that moves the head but is not attached to any vertebrae

Platysma (pla-tiz-ma)

Superficial muscle that covers the front of the neck

Extends from the chest (fascia covering the upper part of pectoralis major and deltoid) up either side of the neck to the chin

Depresses the lower jaw and lower lips

Used in yawning and when creating a pouting expression

The muscles of the posterior of the neck 123

Occipitalis

Masseter

Buccinator

Risorius

Sternocleidomastoid

Platysma

Occipitalis

Masseter

Buccinator

Risorius

Sternocleidomastoid

Platysma

Fig 4.5 The muscles of the head and neck

Student activity

Now complete Activity 4.1 in the resources for this book on Dynamic Learning Online.

Frontalis

Temporalis

Corrugator

Procerus

Orbicularis oculi

Levator labii superioris

Nasalis

Zygomatic minor

Levator anguli oris

Orbicularis oris

Zygomatic major

Mentalis

Depressor labii inferioris

Depressor anguli oris

5 Common Skin Problems Answered

5 Common Skin Problems Answered

Our skin may just feel like a mere shield that protects us from the world outside. But, the fact is, its more than just the mask that keeps your insides in. It is a very unique and remarkable complex organ that reflects our general health.

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Responses

  • Aziz
    How to stop the pouting & spasms from tmj?
    4 years ago

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