The Oral Cavity

Question 1

What muscles make up the Oral Cavity

Answer 1

Hard Palate 
Soft Palate
Palatopharyngeal Arch
Uvula 
Palatoglossal Arch
Oropharynx

Question 2

Describe the function of the Hard Palate and it’s innervation

Answer 2

The Hard Palate is the anterior 2/3 of the palate. It is innervated by the trigeminal nerve V. It has a static function and is important in swallowing and speech.

In swallowing the hard palate provides a surface for the food to be pressed against when chewing

In Speech the hard palate provides a surface for the tongue to press against when making sounds

Question 3

Describe the function of the Soft Palate and it’s innervation

Answer 3

The Soft Palate is the Posterior 1/3 of the Palate. It is innervated by the trigeminal nerve V. It has a dynamic function which elevates and lowers. This affects: Respiration, Resonance and Swallowing

Question 4

What are the muscles of the Soft Palate and their innervation

Answer 4

• Tensor Veli Palatini: tenses the soft palate
• Levator Veli Palatini: elevates soft palate
• Palatoglossus: pulls the soft palate towards tongue
• Palatopharyngeus: tenses soft palate and draws the pharynx forward on swallowing
• Musculus Uvulae: shortens the uvula

All innervated by CN X (Vagus) except the Tensor
veli palatini - CN V (Trigeminal Nerve)

Question 5

What are the Sulci

Answer 5

The Sulci are a ‘groove’ in the mouth.

The Anterior Sulci - Are the space between the front of the lips and the teeth

The Lateral Sulci - Are the space between the gums at the side of the mouth and the cheek

Question 6

What is the role / function of Saliva

Answer 6

Cleanses the mouth e.g. contains proteins and
minerals which protect tooth enamel and
prevent tooth decay and gum disease
 Aids in chewing and swallowing of food
 Important in digestion - contains enzyme
amylase, maltase and lingual lipase which
helps in digesting
 Excretory function – excretes poisonous
substances such as mercury,lead and virus
are excreted via saliva e.g. rabies and mumps
 Helps to facilitate taste by acting as a
“solvent” by dissolving food particles –
dissolved substance then go on to stimulate
taste buds
 Helps to regulate water content in body –
decrease in water content decreases salivary
secretion which results in thirst
 Aids speech production

Question 7

What are the extrinsic muscles of the tongue

Answer 7

The extrinsic muscles of the tongue originate outside of the tongue and are responsible for its movement. They move the tongue relative to other structures within the mouth .

There are 4 extrinsic muscles of the tongue:
HYOGLOSOSSUS:
• depresses and retracts tongue
STYLOGLOSSUS:
• draws tongue up and backwards
GENIOGLOSSUS:
• forward movement and protrusion and also depresses tongue
PALATOGLOSSUS
• Retracts and elevates the tongue (toward the soft palate)

Question 8

What are the intrinsic muscles of the tongue

Answer 8

The intrinsic muscles are contained within the tongue itself they are responsible for deforming its shape

There are 4 intrinsic muscles of the tongue:
Superior Longitudinal
Inverse Longitudinal
Transverse
Vertical

Question 9

What is the motor innervation of the tongue

Answer 9

All of the muscles of the tongue are innervated by CN XII - The hypoglossal nerve APART FROM the extrinsic palatoglossal muscles which is innervated by the Vagus Nerve X and the Glossopharyngeal Nerve CN IX

Question 10

What are the sensory innervation of the tongue

Answer 10

The posterior 1/3 of the tongue are innervated by the Glossopharyngeal Nerve IX - this provides both sensory and taste innervation

The Anterior 2/3 of the tongue are provided by two different cranial nerves. The sensory innervation is provided by the Trigeminal Nerve V and taste is innervated by the Facial nerve VII

Question 11

What are Papillae

Answer 11

Papillae are taste receptors located in the taste buds found on the dorsum of the tongue