THE ORAL CAVITYPAOLO M. ZABAT, RN

ORAL CAVITY

ORAL CAVITYThe oral cavity, or mouth, is the first part of the

digestive tractIt is bounded by the lips and cheeks and contains

the teeth and tongue.

LIPSLips are muscular structures, formed mostly

by the orbicularis muscle.

The color from the underlying blood vessels can be seen through the thin, transparent epithelium, giving the lips a reddish-pink appearance.

TONGUEIs a large, muscular organ

that occupies most of the oral cavity.

Frenulum – A thin fold of tissue that is attached anteriorly to the floor of the mouth.

The tongue moves food in the mouth and, in cooperation with the lips and cheeks, holds the food in place during mastication.

It is a major sensory organ for taste, as well as being one of the major organs of speech.

TONGUE

TEETHNormal adult teeth: 32

teethIt is divided into

quadrants: right upper, left upper, right lower and left lower.

Each quadrant contains: one central and one lateral incisor, one canine, first and second premolars and first, second and third molars.

The third molars are called wisdom teeth because they usually appear in a person’s late teens or early twenties.

TEETHThe teeth of adults are permanent, or

secondary teeth.Most of them are replacements of the

20 primary or deciduous teeth which are lost during childhood.

Each tooth consists of a crown with one or more cusps, a neck and a root.

Pulp cavity – the center of the tooth which is filled with blood vessels, nerves and connective tissue, called pulp.

Dentin – A living, cellular, bonelike tissue surrounding the pulp cavity.

Enamel – An extremely hard, acellular substance covering the dentin of the tooth crown. It protects the tooth against abrasion and acids produced by bacteria in the mouth.

TEETHCementum – is the covering of

the surface of the dentin in the root which helps anchor the tooth in the jaw.

The teeth are rooted within alveoli along the alveolar processes of the mandible and maxillae.

The alveolar processes are covered by dense fibrous connective tissue and moist stratified squamous epithelium, referred to as gingiva or gums.

The teeth are held in place by periodontal ligaments, which are connective tissue fibers that extend from the alveolar walls and are embedded into the cementum.

PALATE AND TONSILS The palate or roof of the oral cavity,

consists of two parts: Hard Palate – the anterior part

that contains bone Soft Palate – the posterior

portion that consists of skeletal muscle and connective tissue

Uvula – is a posterior portion of the soft palate.

The palate separates the oral cavity from the nasal cavity and prevents food from passing into the nasal cavity during chewing and swallowing.

Tonsils – are located in the lateral posterior walls of the oral cavity in the nasopharynx, and in the posterior surface of the tongue.

SALIVARY GLANDSThere are three pairs of

salivary glands: Parotid, submandibular

and sublingual glands.They produce saliva, which is a

mixture of serous and mucous fluids.

Saliva helps keep the oral cavity moist and contains enzymes that begin the process of chemical digestion.

The salivary glands have branching ducts with clusters of alveoli, resembling grapes, at the ends of the ducts.

SALIVARY GLANDS

SALIVARY GLANDSPAROTID GLAND

Largest of the salivary glandsAre serous glands located just anterior to each ear.Parotid ducts enter the oral cavity adjacent to the second upper

molars.SUBMANDIBULAR GLANDS

Produce more serous than mucous secretions.The submandibular ducts open into the oral cavity on each side

of the frenulum of the tongue.SUBLINGUAL GLANDS

The smallest of the three paired salivary glands, produce primarily mucous secretions.

They lie immediately below the mucous membrane in the floor of the oral cavity.

Each sublingual gland has 10-12 small ducts opening onto the floor of the oral cavity.