Lesson 59 - Structure of Oral Cavity

What does the digestive system include?

alimentary canal and accessory organs

What is the alimentary canal also called?

gastrointestinal tract

What is the function of the accessory organs?

help in process of digestion by changing physical form of the food and secreting enzymes and chemicals into alimentary canal

What types of animals have the ability to digest plant material (cellulose)?

herbivores

What types of animals have a longer alimentary canal?

herbivores

What types of animals have a shorter alimentary canal?

carnivores

What is the term for having a single chamber stomach?

monogastric

What is the term for having a compound stomach?

polygastric

What are foregut fermenters?

animals that have fermentation in the earlier part of the GI tract

What are hind-gut fermenters?

animals that have fermentation in the caudal part of the gut

What type of animal digestive systems are seen with hind-gut fermenters?

monogastric

What is prehension?

act of grabbing and bringing food to the mouth

What animal uses their tongue for prehension?

cattle

What animal can use their forelimbs for prehension?

dogs and cats

What is ingestion?

taking food into the oral cavity, lips, tongue

What is mastication?

chewing the food to break it down into smaller pieces

What is insalivation?

act of mixing smaller food pieces with saliva and transforming it into a slimy ball (Bolus) that is ready for swallowing

What is deglutition?

process of swallowing the bolus and transferring it into the stomach

What is another name for the mouth?

os/oris

What is the mouth?

opening at the beginning of the digestive tract that allows food to enter the body

What is the oral cavity?

just after the mouth an area involved in holding food, chewing, mixing food with saliva, and forming bolus

What are the accessory organs?

teeth, tongue, salivary glands, liver, gall bladder, pancreas, anal sacs

What is another name for the oral fissure?

rima oris

What are the margins of the oral cavity?

rima oris to fauces

What is the fauces?

The passage from the mouth to the pharynx (Throat)

What is the fauces marked by that we can visually see?

palatoglossal arches/folds

What are the functions of the mouth and oral cavity?

ingestion, mastication, insalivation

What forms the rim of the mouth?

lips

What is the function of the lips?

ensures proper closure of the rima oris, prevents loss of saliva and food while chewing, sucking milk in the young

What is the point where the upper and lower lips meet?

oral commissure/angle of the mouth

What is another name for lips?

labia oris

What muscle supports the lips?

orbicularis oris muscle

What is present in the mucosa of the lips?

labial glands

What are labial glands?

small salivary glands on the oral surface

What is important about the outer skin of the lips?

keratinization

What makes up the inner mucosa of the lips?

stratified squamous epithelium

What is important about the upper lip in sheep, goats, horses?

prehensile upper lip

What breeds have upper lip flews?

bulldog and bloodhound

What is a lip variation that ruminants have?

backward pointing conical buccal papillae

What does buccal/buccae mean?

cheek

What is the purpose of the conical buccal papillae?

prevent loss of food while chewing

What mucosa contains the backward pointing conical buccal papillae?

labial and buccal mucosa

What boundary of the oral cavity do the cheeks form?

caudo-lateral boundary

What muscle makes up the bulk of the cheeks?

buccinator muscle

What glands are present in the cheeks?

buccal glands

What types of animals have narrow cheeks?

carnivores

What types of animals have wider cheeks?

herbivores

Why do carnivores need shorter cheeks?

needed for hunting because of wider gape

Why do herbivores need wider cheeks?

enough for grazing because of narrow gape

What is the sensory innervation to the lips and cheeks?

maxillary and mandibular branches of the trigeminal nerve

What CN is trigeminal nerve?

CN V

What is the motor innervation to the lips and cheeks?

facial nerve

What CN is facial nerve?

CN VII

What are the main blood supply arteries to the lips and cheeks?

facial artery and maxillary artery

What branches off the facial artery?

superior labial artery and angularis oris artery

What branches off the maxillary artery?

inferior alveolar artery and infraorbital artery

What branches off the inferior alveolar artery?

mental branches

What branches off the infraorbital artery?

lateral nasal artery

What makes up the roof of the oral cavity?

hard and soft palate

What makes up the floor of the oral cavity?

mylohyoideus muscles

What makes up the walls of the oral cavity?

lips and cheeks

What makes of the rostral limit of the oral cavity?

rima oris

What makes up the caudal limit of the oral cavity?

palatoglossal arch

What is the space outside of the dental rows?

vestibule

What is another name for the dental rows?

arcades

What is the space inside the dental rows?

oral cavity proper

What are the organs in the oral cavity?

tongue, teeth, opening of salivary glands

What is another term for palate?

palatum

What are the parts of the palate?

hard and soft palate

What is another name for the hard palate?

palatum durum

What is the rostral bony portion of the palate?

hard palate

What bones are a part of the hard palate?

incisive, maxillary, palatine

What is a structure seen on the palate?

transverse ridges called palatine rugae

What is an opening present in the hard palate?

incisive papilla

What is the incisive papilla?

opening of the incisive ducts on both sides

What are the ducts of the vomeronasal organ?

incisive ducts

What is a unique structure on the cat and bovine hard palate?

backward pointing papillae

What is important about the horse hard palate?

mucosa is very thick in its most rostral part and has a venous plexus

What is a physiologic phenomenon that occurs with horses hard palate?

lampas; venous plexus becomes engorged when incisor teeth erupt

What are other names for the soft palate?

palatum molle or velum palatinum

What makes up the soft palate?

muscles and connective tissue

What is the caudal membranous portion of the palate?

soft palate

What does the soft palate have a relation to?

epiglottis

How is the soft palate and epiglottis ordered in most mammals?

soft palate lies over the epiglottis

How is the soft palate and epiglottis ordered in horses?

epiglottis lies over the soft palate

What is the function of the soft palate?

respiration, swallowing, vomiting

What are some structures that are associated with the soft palate?

palatine tonsils and palatine salivary glands

What muscles are involved with the soft palate?

palatine m., palatinus m., tensor veli palatini m., levator veli palatini m., palatopharyngeus m.

What is the nerve innervation of the soft palate?

pharyngeal plexus

What nerve branches make up the pharyngeal plexus?

branches of the vagus nerve and glossopharyngeal nerve

What cranial nerve is glossopharyngeal nerve?

CN IX

What arteries are involved with the palate?

major and minor palatine

What branches off the major palatine artery?

rostral septal artery

What does the minor palatine artery branch off of?

maxillary artery

What does the major palatine artery branch off of?

descending palatine artery

What arteries do you need to consider when doing a cleft palate repair?

major and minor palatine arteries and rostral septal arteries

What structure does the greater palatine nerve go through?

greater palatine foramen

What travels through the greater palatine foramen?

greater palatine nerve and major palatine artery

Where does the greater palatine nerve branch from?

maxillary nerve

Where does the maxillary nerve branch from?

trigeminal nerve