(Based on PP 2.2) Anatomy of Teeth, Facial Muscles, and Tongue Innervation

4 types of teeth

1. incisors

2. canines

3. premolars

4. molars

Hardest part of the tooth

Enamel

Orbicularis Oris

Closes the lips (VII Facial).

Risorius and Buccinator

Retract the lips (VII facial).

The 3 muscles that elevate the upper lip

Levator labii superioris

Zygomatic minor

Levator labii superioris alaeque nasi

All innervated by VII Facial

Two muscles retract and elevate the corners of the lips "Smile muscles"

Levator anguli oris

Zygomatic major

Innervation: Both VII facial

3 muscles involved in depressing lower lip and pouting

Depressor labii inferioris

Depressor anguli oris

Mentalis

Innervation: VII Facial

Platysma

Depresses the mandible (VII Facial)

3 muscles that depress the mandible

Mylohyoid, geniohyoid and platysma

3 muscles that elevate the mandible

The masseter, temporalis, and medial pterygoid

All innervated by V trigeminal

Sphenoid bone

Shaped like bat (or butterfly) wings

Attachment for muscles of chewing and movement of velum

Pterygoid plates

Lateral pterygoid

Protrudes the mandible (V Trigeminal)

Parts of the tongue

Blade (body), back, tip (apex), base, root

Tongue is divided longitudinally

Fibrous Midline Septum divides left and right halves.

Septum originates at body of hyoid.

What part of the tongue is the image showing?

Lingual Frenulum

How are the muscles of the tongue divided? (Hint: 2)

Extrinsic (outside): Change tongue position.

Intrinsic (inside): Change tongue shape.

Primary mover of tongue: retract, protrude, depress (XII Hypoglossal)

Genioglossus

Hyoglossus and Chondroglossus (considered part of Hyoglossus)

Pull the sides of the tongue down (XII Hypoglossal)

Styloglossus

Pulls the tongue up & back (XII Hypoglossal)

Palatoglossus

Depresses (pulls down) the soft palate & elevates the back of the tongue.

Innervation: (X Vagus)

Superior Longitudinal Muscle

Shortens the tongue; curls the tip and sides upward
CN XII (Hypoglossal)

Inferior Longitudinal Muscle

Shortens the tongue; curls the tip and sides downward

Transverse Muscle

Narrows and elongates the tongue (makes it skinny).

CN XII (Hypoglossal)

Vertical Muscle

Flattens and broadens the tongue.

CN XII (Hypoglossal)

What are the extrinsic muscles of the tongue?

Genioglossus, hyoglossus, styloglossus & palatoglossus.

What are the intrinsic muscles of the tongue?

Superior/Inferior Longitudinal, Transverse, Vertical.