Vet Med Term - Chapter 6

Digestive system (or tract) / alimentary system / gastrointestinal (GI) system (or tract)

Body system that is a long, muscular tube that begins at the mouth and ends at the anus

Functions of digestive system

• intake and digestion of food/water

• Absorption of nutrients

• Eliminations of solid waste products

Structures of digestive system

• mouth or oral cavity

• Pharynx

• Esophagus

• Stomach

• Small intestines

• Large intestines

• Accessory organs of digestion

Mouth / oral cavity

Mechanical and chemical process of digestion begins in mouth

Or/o & Stomat/o

Mouth

Oral cavity contains

• lips

• Cheeks

• Hard and soft palates

• Salivary glands

• Tongue

• Teeth

• Periodontium

Lips

Form the opening to oral cavity

Cheil/o and labi/o

Lips

Labia

Med term for lips

Labium

Single lip

Cheeks

Forms walls of oral cavity

Bucc/o

Cheeks

Buccal

Pertaining to or directed toward cheek

Palate

Forms roof of mouth

Palat/o

Palate

Hard palate

Forms body rostral portion of palate that is covered with specialized mucous membrane

Rugae

Irregular folds that are apart of the specialized mucous membranes of the hard palate

Rug/o

Wrinkle or fold

Soft palate

Forms flexible caudal portion of palate

• involved in closing off nasal passages during swallowing so food does not move into nostrils

Tongue

Moveable muscular organ used for tasting/processing food, grooming, and articulating sound

Gloss/o and lingu/o

Tongue

Papillae

Elevations on tongue

• may appear:

• Filiform

• Fungiform

• Vallate

Filiform

Threadlike

Fungiform

Mushroomlike

Vallate

Cup-shaped

Frenulum

Band of connective tissue that connects tongue to ventral surface of oral cavity

Lingual surface of cheek

Is side adjacent to tongue

Maxilla / mandible

Boundaries of oral cavity

Gnath/o

Jaw

Prognathia (sow mouth)

Having an elongated or overshot mandible

Brachygnathia (parrot mouth)

Having a shortened or undershot mandible

Dent/o, dent/i, odont/o

Teeth

Dentition

Refers to teeth as a whole

• arranged in the maxillary and mandibular arcades

Endodontics

Branch of dentistry that involves treatment of diseases that affect the tooth pulp

Exodontics

Branch of dentistry that involves extraction of teeth and related procedures

Oral surgery

Branch of surgery that involves surgical correction of the jaw, gums, and inside of the mouth

Orthodontics

Branch of dentistry that involves the guidance and correction of malocclusion

Periodontics

Branch of dentistry that studies and treats the diseases of tooth-supporting structures

Deciduous dentition / primary dentition

The temporary set of teeth that erupt in young and are replaced at/near maturity

Decidu/o

Shedding

Permanent dentition

Set of teeth designed to last a lifetime

Mixed dentition

Period when both deciduous and permanent teeth are present

Retained deciduous tooth

Deciduous tooth that has not been shed and may be extracted professionally

4 types of teeth

• incisor

• Canine

• Premolar

• Molar

Incisor / I

Front tooth used for cutting

Canine / fang / cuspid / C

Long, pointed bonelike tooth located between incisors and premolars

Cusp

Having tapering projection

Cuspid

Having one point

Premolar / bicuspids / P

Cheek tooth found between canine and molars

• called bicuspids bc they have 2 points

Molar / M

Most caudally located permanent cheek tooth used for grinding

Molar came from Latin word

To grind

Dental formula

Represents type and # of each tooth found in the species

• only one side of mouth is represented and is preceded by a 2 to indicate that the arrangement is the same on both sides

Cheek teeth

Premolars and molars

Needle teeth

Deciduous canines and third incisor of pigs

Wolf teeth

Rudimentary premolar 1 in horses

Milk teeth

First set of teeth

Tusks

Permanent teeth of pigs

Carnassial tooth

Large, shearing cheek tooth; upper P4 and lower M1 in dogs; upper P3 and lower M1 in cats

Fighting teeth

Set of six teeth in llamas that include upper vestigial incisors and upper and lower canines on each side

Selenodont

Animals with teeth that have crescents on their grinding surfaces (eg ruminants)

Lophodont

Animals with teeth that have ridged occlusal surfaces (eg equine)

Bunodont

Animals with teeth that have worn, rounded surfaces (eg swine)

Hypsodont

Animals with continuously erupting teeth (eg cheek teeth of ruminants)

Pleurodont

Animals with teeth attached by one side on the inner jaw surface (eg lizards)

Brachydont

Animals with permanently rooted teeth (eg carnivores)

Dental formula for adult dog

2 (I 3/3, C 1/1, P 4/4, M 2/3)

• total = 42

Dental formula for adult cat

2 (I 3/3, C 1/1, P 3/2, M 1/1)

• total = 30

Dental formula for adult bovine, sheep, goat

2 ( I 0/4, C 0/0, P 3/3, M 3/3) or 2 ( I 0/3, C 0/1, P 3/3, M 3/3)

• total = 32

Dental formula for adult horse

2 ( I 3/3, C 1/1, P 3-4/3, M 3/3)

• total = 40 or 42

Dental formula for adult pig

2 ( I 3/3, C 1/1, P 4/4, M 3/3)

• total = 44

Dental formula for adult female llama

2 ( I 1/3, C 1/1, P 2/1, M 3/2)

• total = 28

Dental formula for adult male llama

2 ( I 1/3, C 1/1, P 2/1, M 3/3)

• total = 30

Dental formula for adult rabbit

2 ( I 2/1, C 0/0, P 3/2, M 3/3)

• total = 28

Dental formula for adult ferret

2 ( I 3/3, C 1/1, P 3/3, M 1/2)

• total = 34

Dental formula for adult chinchilla

2 ( I 1/1, C 0/0, P 1/1, M 3/3)

• total = 20

Dental formula for adult gerbil

2 ( I 1/1, C 0/0, P 0/0, M 3/3)

• total = 16

Dental formula for adult hamster

2 ( I 1/1, C 0/0, P 0/0, M 3/3)

• total = 16

Dental formula for adult rat and mouse

2 ( I 1/1, C 0/0, P 0/0, M 3/3)

• total = 16

Dental formula for adult guinea pig

2 ( I 1/1, C 0/0, P 1/1, M 3/3)

• total = 20

Triadan system

• each tooth has a 3 digit #

• 1st digit (quadrant #) → represents the quadrant where the tooth is located

• 2nd and 3rd digit → represents individual teeth; starts at rostral midline and increases in # from rostral to caudal

Ex of Triadan system in dogs and cats

Incisors are 01

• incisor on right maxilla = 101

• Incisor on left maxilla = 201

• Incisor on left mandible = 301

• Incisor on right mandible = 401

Tooth anatomy

• enamel

• Cementum

• Dentin

• Pulp

• Apical foramen

• Periodontia

• Alveoli

• Alveolar bone

• Periodontal ligament

• Gingiva

• Gingival sulcus

Enamel

Hard white substance covering the dentin of crown of tooth

• located in crown

Cementum

Bonelike connective tissue that covers roof of tooth

• located in root

Dentin

Connective tissue surrounding tooth pulp

Pulp

Inner part that contains nerves, vessels, and loose connective tissue

Apical foramen

Hole at tip of root where nerves and blood vessels enter tooth

Periodontia

Structures that support teeth

Alveoli (single: alveolus)

Sockets or saclike dilations teeth are situated to

Alveolar bone

Thin layer of compact bone that forms tooth socket

• surrounds roots of teeth

Periodontal ligament

Fibrous structure that holds tooth in alveolus

• contains collagen fibers that are anchored to cementum and alveolar bone

Gingiva (gums)

Mucous membrane that surrounds teeth and forms mouth lining

Gingiv/o

Gums

Gingival sulcus

Space that surrounds tooth

• located between tooth and gingival margin

Salivary glands

Group of cells that secrete a clear substance containing digestive enzymes (saliva)

Sialaden/o & sial/o

Salivary glands

Saliva

Moistens food, begins digestive process by aiding in bolus formation and some digestive enzymes activity (amylase in some species), and cleanses the mouth

Mandibular salivary gland

Found near mandible

Sublingual salivary gland

Found under tongue

Zygomatic salivary gland

Found medial to zygomatic arch