Oral+Cavity

**Tongue:**
 * Oral Cavity ** The digestive organs of the oral cavity are:
 * Tongue
 * Teeth [[image:Tongue2.jpg width="280" height="271" align="right"]]
 * Salivary Glands
 * The primary functions of the tongue are:**
 * 1) Mechanical processing of food by compression, abrasion, and distortion
 * 2) Manipulation of food to assist in chewing and to prepare material for swallowing
 * 3) Sensory analysis by touch, temperature, and taste receptors
 * 4) Secretion of mucus and the enzyme lingual lipase


 * Anatomy of the tongue:**
 * Divided into an anterior body and a posterior root
 * The tongue contains two groups of skeletal muscles: intrinsic and extrinsic tongue muscles
 * The superior surface of the oral portion contains lingual papillae
 * There are four different types of papillae: filiform, fungiform, circumvallate, and foliate papillae
 * All the papillae, except for the filiform have taste buds on their surface and can detect sweet, sour, bitter, salty, and umami tastes
 * Along the inferior midline is the lingual frenulum which connects the body of the tongue to the floor of the oral cavity and restricts the movement of the tongue


 * Histology of the tongue:**
 * Each papilla is covered by a thickened epithelium that assists in the movement of materials by the tongue
 * Epithelium covering inferior surface of tongue is thinner and therefore more delicate than the superior surface
 * Lingual frenulum is a thin fold of mucous membrane

Ankyloglossia is a condition in which the lingual frenulum is too restrictive and inhibits normal speech and eating processes. Teeth: ** This process:**
 * The primary function of the teeth is the mastication, or chewing, of food.[[image:1121.jpg width="320" height="256" align="right"]]
 * 1) Breaks down tough connective tissue in meat and the plant fibers in vegetable matter
 * 2) Helps saturate the materials with salivary secretions and enzymes


 * Anatomy and histology of the teeth:**
 * There are four different types of teeth: incisors, cuspids, bicuspids, and molars
 * The exposed portion of the tooth is referred to as the crown
 * The part that is not exposed is the root
 * The bulk of each tooth is composed of a mineralized matrix similar to bone called dentin
 * The dentin of each tooth in covered by a layer of enamel, which is the hardest biologically manufactured substance
 * A specialized bony substance called cementum covers the root of a tooth
 * An interior chamber called the pulp cavity receives blood vessels and nerves from the root canal, a narrow tunnel located at the base of the tooth
 * Blood vessels enter the root canal through an opening called the apical foramen
 * The root of each tooth sits in a bony socket called the alveolus
 * The gingival sulcus surrounds the neck of each tooth and form an attachment with epithelial cells to prevent bacteria form entering the gingiva


 * Some dental problems include:**
 * Gingivitis- a condition the occurs when the connection between the epithelial cells of the gum and the begins to break down which can lead to bacterial infection of the gingivae
 * Periodontal disease- occurs when the gums recede from the teeth which allows bacteria to enter and erode the teeth and is the most common cause of the loss of teeth

**Salivary Glands:** Salivary glands produce 1.0-1.5 liters of salvia each day. Saliva is composed of 99.4% water and the remaining 0.6% contains electrolytes, buffers, glycoproteins, antibodies, enzymes, and waste products.


 * The functions of saliva production as you eat are:**
 * 1) Lubricating the mouth
 * 2) Moistening and lubricating materials in the mouth
 * 3) Dissolving chemicals that can stimulate the taste buds and provide sensory information about the material
 * 4) Initiating the digestion of complex carbohydrates before the material is swallowed

The secretion of saliva helps keep the oral cavity clean in several ways:
 * Buffers in saliva keep the pH near 7.0 to prevent the buildup of acids produced by bacterial action
 * Also contains antibodies and lysozymes to help control populations of oral bacteria
 * Without salivary secretions, the bacterial population would explode leading to recurring infections and progressive erosion of the teeth and gums


 * Three types of salivary glands secrete into the oral cavity:**
 * 1) Parotid salivary glands
 * 2) Sublingual salivary glands
 * 3) Submandibular salivary glands


 * Parotid Salivary Glands**
 * Each gland has an irregular shape and extends from the mastoid process of the temporal bone to the outer surface of the masseter muscle
 * Produce a thick, serous secretion that contains the enzyme salivary amylase, which breaks down carbohydrates
 * Secretions are drained by the parotid duct which empties into the vestibule at the level of the second upper molar
 * About 25% of saliva originates in these glands
 * Sublingual Salivary Glands**
 * Covered by the mucous membrane of the floor of the mouth
 * Produce a watery, mucous secretion that acts as a buffer and lubricant
 * Sublingual ducts open along either side of the lingual frenulum
 * About 5% of saliva originates in these glands


 * Submandibular Salivary Glands**
 * Lie in the floor of the mouth in the mandibular groove, a depression along the inner surfaces of the mandible
 * Produce a mixture of buffers, glycoproteins called mucins, and salivary amylase
 * Submanibular ducts open into the mouth on either side of the lingual frenulum immediately posterior to the teeth
 * About 70% of saliva originates in these glands

All three glands are enclosed in a capsule of connective tissue and are internally divided into lobes.

The mumps virus most often targets the salivary glands.

Works Cited: //Fundamentals of Anatomy & Physiology// Textbook http://en.wikipedia.org/wiki/Tongue http://en.wikipedia.org/wiki/Teeth http://en.wikipedia.org/wiki/Salivary_glands