11.02.11+-+Oral+Cavity

Oral Cavity


 * 1. Name three functions of the oral cavity. What are some of the challenges by overlapping functions (respiratory and digestive) in both adults and newborn infants.**

Respiration, Digestion, Phonation.

Breathing + Digesting = Choking


 * 2. Describe the two compartments of the oral cavity and the structures that delineate the boundaries of each compartment (including skeletal, muscular, and epithelial).**

There's the oral cavity proper and the oral vestibule which are divided by the dental arches. Outer border of the oral vestibule is the cheek. Posterior border of the oral cavity proper is the uvula and palatoglossal and palatopharyngeal arches. It is open to the oropharynx. The layers of the cheek: the mucous membrane is the inner layer of the check followed by the circumoral muscles: orbicular is otis, buccinator, risorius, depressors and elevators of the lips. Then covered by skin. The lips are like the cheeks, but are the valves of the oral fissure.


 * 3. Name the four categories of adult teeth and terminology used to describe the various parts and surfaces.**

Ordering goes A-P. Incisors - cutting edge Canines - pointy Premolars - 2 cusps Molars - 3 or more cusps


 * 4. Describe the neural innervations of and blood supply to the teeth and gingival.**

The maxillary artery via the superior and inferior alveolar arteries supplies the maxillary and mandibular teeth. The anterior superior alveolar nerves branch from the infraorbital nerve, the continuation of V2 in the orbit. Posterior and middle superior alveolar nerves branch from V2 pre-orbit. All innervate the maxillary teeth. The inferior alveolar nerve is the terminal branch of V3 and innervates the mandibular teeth.


 * 5. Compare and contrast the structure and function of the hard and soft palate including bones, muscles, vessels and mucosa.**

Hard palate is formed by 2/3 maxillary bone and 1/3 palatine bone. Soft palate is formed by aponeurosis of soft palate and muscles deep.

Tensor veli palatini Levator veli palatini Palatoglossus Palatopharyngeus Musculus uvulae


 * 6. Describe the role of the oral cavity, palate, and tongue in the sequence of swallowing (deglutition).**

Oral Cavity: tongue presses bolus to palate. Soft palate holds it in then swings superoposteriorly, bolus sent down throat into oropharynx by tongue.


 * 7. Define the landmarks that subdivide the dorsum of the tongue into different regions. What are the features unique to each of these areas?**

The anterior and posterior tongue is divided by the terminal sulcus, the angle of which points posteriorly.

Anterior to the terminal sulcus there are four regions of lingual papillae: foliate, vallate, filiform, fungiform. Foliate are in creases in the posterolateral surface. Vallate are mountainous and line the terminal sulcus. Filiform fill the middle surfaces of the anterior tongue (aka lingual papillae) and fungiform are small mushroom shaped spots on the apex and margins of the tongue.

The posterior tongue is covered with the lingual tonsils, a collection of lymphoid nodules. It resides in the oropharynx.


 * 8. Describe the three functions of the tongue and contributions of intrinsic and extrinsic muscle of its movement.**

The three functions of the tongue are to help with articulation, squeezing food into the oropharynx as part of deglutition, and taste. It is also involved with mastication and oral cleansing.

As a general rule, the intrinsic muscles change the shape of the tongue, while the extrinsic muscles change the location/orientation.

The intrinsic muscles are the superior and inferior longitudinal, transverse, and vertical muscles of the tongue. They don't make up the mass of the tongue, but instead the outer surfaces. Superior longitudinal lays on top. Inferior longitudinal lays on the lateral walls of the inferior surface. Transverse and vertical occupy a region just inferior/deep to superior longitudinal.

The extrinsic muscles (genioglossus, hyoglossus, styloglossus, and palatoglossus) move the tongue. The genioglossus is the largest portion of the tongue.

All muscles of the tongue but the palatoglossus (really a palate muscle) are innervated by CN XII, hypoglossus.


 * 9. Describe the structures that constitute the floor of the mouth and base of the tongue**

The floor of the mouth and base of the tongue are formed by:

The structure of the floor of the mouth is given by the mandible and hyoid bones, which serve as attachment points for the anterior belly of digastric, mylohyoid, geniohyiod. Superior to the floor of the mouth is the base of the tongue, which is formed by the genioglossus. The sublingual (salivary) gland is there also.