anatomy: digestive system

Digestive System

consists of an alimentary canal, accessory glands which include the salivary gland, liver, and pancreas

Mouth to Anus

alimentary canal

Prehension

Mastication

Deglutition

Digestion

Absorption

Storage of Nutrients

Excretion

processes involved in digestive system

Prehension

process of seizing or grasping or otherwise getting food into the mouth

Mastication

process whereby food is broken down by mechanical digestion in the oral cavity

Deglutition

process that makes something pass from the mouth

Digestion

stomach receives ingesta from esophagus

Stomach

__ as temporary storage of ingesta needed for digestion

Liver

many nutrients are stored in the __

Absorption

breaking down food into the small molecules the body can use

Excretion

the removal of metabolic waste products from the body of an organism

Mouth

Pharynx

Esophagus

Stomach

Small Intestine

Large Intestine

Anal Canal

consecutive segments of the digestive system

Mouth

composed of the oral cavity and its accessory organs

Oral Cavity

it extends from the lips to the entrance of the pharynx

Oral Cavity Proper

Oral Vestibule

two parts of oral cavity:

Oral Cavity Proper

bounded rostrally by the lips, laterally by the cheeks, dorsally by the hard palate and ventrally by the tongue

Oral Vestibule

spaces between the lips and the teeth

Labial Vestibule

Buccal Vestibule

2 parts of oral vestibule

Labial Vestibule

between lips and incisors

Buccal Vestibule

between lips and cheek teeth

Upper Lip (Labium superius)

Lower Lip (Labium inferius)

Labial Glands

parts of labia oris/lips

Philtrum

• distinct median cleft from the nasal septum to the upper lip

• divides the upper lip of carnivores and small ruminants

Pendulous

in dogs, upper lip is __ and presses on the lower one

Gums Gingivae

• part of the oral mucosa

• united to the periosteum of the alveolar processes of the jaws

Margo Gingivalis

encircle the neck of the teeth

Papilla Gingivalis (interdentalis)

mucosal elevation between the teeth

Sulcus Gingivalis

groove between gingiva and tooth

Palatum durum

latin of hard palate

Hard Palate

widest at the 4th cheek tooth and median raphe is usually replaced by a ridge

6-10 pairs

the number of palatine ridges in dogs

Palatum molle

latin word for soft palate

Anterior Pillar

two short, thick folds from the free border of the oral surface to either side of the tongue

Posterior Pillar

from the free border of the aboral surface to the anterior of the esophagus

Tonsilar Sinus

• between the AP and PP

• houses the tonsil

Fusiform Tonsil

__ situated in the sinus

Levator Veli Palatini

Tensor Veli Palatini

Palatines

intrinsic muscles of the soft palate

Palatopharyngeus

extrinsic muscles of the soft palate

Teeth

• principal organ of mastication

• function together with the jaw, masticatory muscles, lips and tongue in the prehension and mastication of food.

• Arranged in two dental arcades, one associated with the mandible and one with the incisive and maxillary bones.

Incisors

• intended for scraping

• help remove debris from coat

Canines

• used to grip objects

• keep food and toys in place

Premolars

• sharp edges tear food apart

• assist with chewing

Molars

• breakdown the hardest items

• located in the back of the mouth

Milk Teeth

diphyodont is also called __

Diphyodont

they develop a set of deciduous teeth that fall out and replaced with permanent teeth

Heterodont

various types of teeth that are specialized for different aspects of prehension and mastication

Incisors

Canines

Premolars

Molars

types of heterodont teeth

Crown

Neck

Root

parts of teeth

Crown

visible above the mucous membrane of the gum

Neck

the line junction of crown and root

Homodont

when all the teeth are similar/uniform as in the crocodile

Heterodont

when all the teeth have undergone differentiation into molars, premolars, incisors, etc.

Bunodont

when several primitive cones come together to form one tooth as in the cheek teeth of the pig

Lophodont

when the cones become ridges as in the cheek teeth of horse

Selenodont

when the ridges becomes sharp as in the cheek teeth of ox

Brachydont

when the enamel is restricted to the crown as in the dog, pig, human

Short-Crowned Teeth

brachydont is also known as __

Hypsodont

when much of the crown is embedded in the gum as in the cheek teeth of the horse

High-Crowned Teeth

hypsodont is also known as __

Occlusal Surface (Masticatory)

Contact Surface

Vestibular Surface

Lingual Surface

surfaces of the teeth

Occlusal Surface

faces the opposite dental arch

Contact Surface

faces side adjacent to the next tooth

Vestibular Surface

faces the lips and cheeks

Lingual Surface

faces the tongue

Incisors

implanted in the incisive bone and the body of the mandible

Ruminants

they don’t have incisors

Canines

eyeteeth, bridle teeth, holding teeth, tusk, or tushes

Canine Teeth

robust, long pointed and slightly curved

Cheek Teeth

premolars and molars are also known as __

Premolars and Molars

grinding teeth forming the sides of the dental arch

Anterior

premolars are __ to the molars

Permanent Dentition

molars are found only in __

Carnassial Teeth or Sectorial Teeth

upper 4th premolar and 1st lower molar teeth are the largest teeth and are referred to as __

2 (I3/3, C1/1, P4/4, M0/0) = 32

temporary dental formula of dog

2 (I3/3, C1/1, P4/4, M2/3) = 42

permanent dental formula of dog

Overshot - Prognathia

• elongated jaw

• sow mouth

Undershot - Brachygnathia

• shortened jaw

• parrot mouth

Tongue

fills the oral cavity while the upper and lower teeth are in contact

Rami of Mandible

tongue situated on the floor of the oral cavity between __

Mylo-Hyoid Muscles and Hyoid Bone

tongue supported by __

Lingual and Sublingual Arteries

tongue supplied by the paired __

Hypoglossal Nerve (VIII)

motor verve supply of tongue

Trigeminal (V)

Facial (VII)

Glossopharyngeal (IX)

Vagus (X)

sensory nerve supply of tongue

• prehension of food

• sorting solid food in some animals

• intake liquid

• sucking of the newborn

• tactile organ

• chemical selection of food

• heat dissipation

functions of tongue

Papillae

the dorsum of tongue is covered with __

Mechanical Papillae

Gustatory Papillae

papillae can be grouped either as __

Mechanical Papillae

cornified and aid in licking while protecting deeper structures

Gustatory Papillae

covered in taste buds

Filiform papillae

Conical Papillae

Marginal Papillae

parts of mechanical papillae

Filiform Papillae

• smallest and most common; looks like hair

• shorter and smaller in horse to have velvety appearance

• heavily cornified in cattle and cat

Conical Papillae

bigger but less frequent, they are scattered widely over the dorsal surface of cat’s tongue and in the base and torus linguae of the tongue of cattle

Marginal Papillae

• present in rostral half of the tongue of new-born carnivores and piglets that aids in suckling milk

• disappears when the diet changed to solid

Fungiform Papillae

Foliate Papillae

Vallate Papillae

gustatory papillae has:

Fungiform Papillae

• looks like tiny mushroom

• scattered together with the filiform and can also be considered as mechanical

• they are occasionally encountered in the ox and horse

Foliate Papillae

• series of leaf-shaped ridges separated by crypts

• found along the border of the tongue just in front of the palatoglossal arch

• usually absent in ruminants

• longest in horse (7-8um)

Vallate Papillae

• with circular projections

• largest and least numerous

• located on the dorsum in front of the root

Dog Tongue

• wide, thin, and mobile

• dorsum marked by median groove

• long backward pointing papillae on the root

Lyssa

inferior part of the tip has cord of fibrous tissue and it is called __

Cat Tongue

mucous membrane is very thick and highly cornified

Parotid

Mandibular

Sublingual

major salivary glands

Labial

Buccal

Palatine

minor salivary glands