(46) head and neck

Muscles of the Head and Neck

Frontalis

  • Location: Forehead, over the frontal bone

  • Function: Raises the eyebrows (elevates eyebrows)

  • Action Visualization: Fibers shorten to pull up on the eyebrow; intuitive muscle action.

Temporalis

  • Location: Temple area, over the temporal bone

  • Attachment: Mandible (lower jaw)

  • Function: Elevates the mandible; involved in chewing

  • Visual Cue: Pulsation seen on the temple during chewing (e.g., chewing gum).

Zygomaticus

  • Location: Attached to the zygomatic bone

  • Function: Raises the corner of the mouth (smiling)

  • Visual Cue: Muscle pulls down to the edge of the mouth, facilitating a smile.

Orbicularis Oculi

  • Shape: Circular muscle around the eye

  • Function: Closes the eye; enables winking and blinking

  • Action Visualization: Circular fibers contract to close the eye.

Orbicularis Oris

  • Shape: Circular muscle around the mouth

  • Function: Closes the mouth; known as the "kissing muscle" (allows puckering)

  • Additional Note: Numerous other muscles surround the mouth, but they are not required to know for this list.

Masseter

  • Function: Elevates the mandible; prime mover for chewing (mastication)

  • Alternative Pronunciation: Can be pronounced as "meider".

Sternocleidomastoid

  • Location: Paired muscles on either side of the neck

  • Origin: Clavicle and sternum

  • Insertion: Mastoid process (skull)

  • Functions:

    • Active Breathing: Assists in deep inhalation by pulling up the rib cage to expand lungs.

    • Head Movement:

      • Rotation: Contraction of one muscle rotates the head to the side.

      • Flexion: Contraction of both muscles pulls head forward (nodding down to the chest).

Muscles of the Head and Neck

  • Frontalis

    • Where? On your forehead.

    • What does it do? It helps to lift your eyebrows, kind of like when you’re surprised!

  • Temporalis

    • Where? By your temples, on the side of your head.

    • What does it do? It helps you chew your food by lifting your jaw up and down. You might see it pulsing when you chew gum!

  • Zygomaticus

    • Where? Next to your cheekbone.

    • What does it do? It helps to lift the corners of your mouth when you smile.

  • Orbicularis Oculi

    • What is it? A round muscle around your eye.

    • What does it do? It helps you close your eyes, like when you wink or blink.

  • Orbicularis Oris

    • What is it? A round muscle around your mouth.

    • What does it do? It helps you close your mouth and puckering, like when you’re blowing a kiss.

  • Masseter

    • What does it do? It’s a strong muscle that helps you chew—it's the main one for chewing food!

  • Sternocleidomastoid

    • Where? On both sides of your neck.

    • What does it do? It helps you breathe deeply by lifting your chest and also lets you turn your head side to side or nod down like you're saying "yes."