Anat 5.1

• Splanchnology is the study of the organs responsible for the maintenance and perpetuation of the individual.
• The digestive system is concerned with the nutrition of the body and includes prehension of food, mastication, digestion, absorption, storage of nutrients and excretion of unabsorbed portion of the food.
• The digestive apparatus consists of the oral cavity, pharynx, alimentary canal (esophagus, stomach, small intestine and large intestine), and accessory organs such as salivary glands, liver, gall bladder, pancreas, and anal sac.
• The oral cavity, which designates the mouth, is divided into the vestibule, oral cavity proper, and the oral fissure.
• The oral cavity proper assists in sucking and in prehension of food, and is bounded by the lips, cheeks, teeth, gums, and margins of the jaw, hard palate, tongue and reflected mucosa.
• When the mouth is closed, the two divisions communicate via the interdental spaces, especially the large space (diastema) between the incisors and the cheek teeth.
• Other structures in the oral cavity include the oral fissure, openings of the parotid and zygomatic salivary ducts, sublingual caruncle, sublingual fold, incisive papilla, and incisive duct.
• The oral cavity is continuous caudally with the isthmus of the fauces and with the oral pharynx.
• The lips, which bound the oral fissure and form the rostral and most of the lateral boundaries of the vestibule, are thin and incapable of purposeful movements.
• The vestibular surface (outer surface) of a tooth faces the lip or cheek.
• Cheek Teeth are divided into Premolars and Molars, characterized by multiple roots which provide firmer anchorage but make extraction difficult.
• The contact surface of a tooth is next to a neighboring tooth of the same arcade (row).
• The lingual surface of a tooth faces the tongue.
• The buccal surface of a tooth is next to the cheek.
• The dog's molars are tubulosectorial in structure, capable of shearing or cutting food, and are specifically of a tubulosectorial type.
• Deciduous (Temporary) teeth, also known as 'baby teeth', develop early in life, are fully erupted and functional in the second month after birth, and are smaller and fewer in number than the permanent dentition.
• The mesial contact surface of a tooth faces the median plane on the incisors, and rostrally on the canine and cheek teeth.
• Canines, or piercers, are caudal to the corner incisors and are separated by an interdental space; they are the longest teeth in dog, are well-developed with large roots, and are used for tearing and separation of a food mass.
• The labial surface of a tooth is next to the lip.
• Permanent teeth, the second set of teeth replacing the deciduous dentition as the jaws have become longer and larger, last throughout the adult life.
• Cheek Teeth, or grinders, are all teeth caudal to the canines.
• Incisor I or Central incisor has a contact surface, a distal contact surface, a mesial contact surface, a vestibular surface, an occlusal surface, and a lingual surface.
• The distal contact surface of a tooth faces away from the median plane on the incisors, and caudally on the canine and cheek teeth.
• Incisors, or cutters/nippers, are the most forward teeth in the mouth, embedded in the incisive bone and incisive part of the mandible, and are principally used for cutting.
• Incisor II or Intermediate incisor and Incisor III or Corner incisor increase in size from the central to the corner incisor.
• The occlusal (masticatory) surface of a tooth makes contact with a tooth from the opposite jaw and is the principal wearing surface.
• The teeth composing the arches are anchored in sockets, or alveoli, of the upper and lower jaws.
• Dental arches refer to the arrangement of teeth into two opposing superior (upper) and inferior (lower) arches, with the lower arch being narrower and usually shorter than the upper.
• Marginal papillae help in preventing milk from spilling over the tongue and aid in sealing the lips around the nipple for suction.
• The growth and maintenance of taste buds depend upon intact sensory nerves.
• Conical papillae are mechanical and tactile.
• Each conical papilla stands on a wide circular base and narrows to a thin, hard point at its apex.
• Taste buds are pear-shaped groups of epithelial cells located in the gustatory papillae: fungiform, vallate, and foliate papillae.
• Foliate papillae are two groups in the dog, each located on the dorsolateral aspect of the caudal third of the tongue rostral to the palatoglossal arch.
• Conical papillae are found on the dorsum of the caudal one-third of the tongue.
• Each group of foliate papillae contains 8-13 papillae, alternating with 9-14 crypts that parallel the papillae and separate them from one another in a leaflike arrangement.
• Vallate papillae are located on the caudal-third of the dorsum of the tongue, marking the boundary between the filiform papillae of the oral part and the conical papillae of the pharyngeal part of the tongue.
• Four types of cells are found in taste buds: Dark or Type I cell, Light or Type II cell, Type III cell, and Basal cell.
• Premolar carrying space is the area of lack of occlusal contact which extends from the canine teeth to the third premolars.
• Fungiform area is sensitive to sweetness, sourness and saltiness, areas innervated by glossopharyngeal- insensitive to sweet and salt tastes, areas innervated by chorda tympani- sensitive to sweetness, sourness and saltiness.