AGR 511 - Exam 3

Thoracic Cavity

Thoracic Cavity

space within the thorax

What does the thoracic cavity contain?

thoracic organs
pleura
pleura cavities
pericardium
pericardial cavity

What is the cranial opening of the thoracic cavity?

thoracic inlet

What is the caudal opening of the diaphragm?

closed by the diaphragm

Abdominal Cavity

space within the trunk

between the diaphragm and pelvic cavity

Aortic hiatus

opening in the dorsal part of the diaphragm

What is the aortic hiatus passage to?

passage of the abdominal aorta

Esophageal hiatus

ventral to the aortic hiatus

Esophageal hiatus is passage to what?

Esophagus, ventral and dorsal vagal trunks, and esophageal vessels enter the abdomen here

Caval foramen

opening in the center of the diaphragm

What passes through the caval foramen?

caudal vena cava passes through

Crura portion of the diaphragm

lumbar portion of the diaphragm

dorsal part consisting of the right and left crura

What does the crura connect to? what does this form?

connect to ventral side of the lumbar vertebral bodies

forms the aortic hiatus

Costal portion of the diaphragm

lateral muscular part of the diaphragm

extends between the thoracic wall and tendinous center

Sternal portion of the diaphragm

ventral muscular part

Tendinous center of the diaphragm

V-shaped aponeurotic center of the diaphragm

Cupula portion of the diaphragm

cranial part of the dome of the diaphragm

Peritoneal cavity

peritoneal lining

lines abdominal cavity and into pelvic cavity

Pelvic cavity

bound by two hip bones, sacrum, first two caudal vertebrae

contains rectum, anal canal, pelvic parts of the reproductive and urinary viscera

Mouth

opening between lips or the whole oral cavity

Oral cavity

space extending from lips to pharynx

bound laterally by cheeks

Labial Vestibule

space between cheek teeth and cheeks

Frenulum

central fold of mucous membrane connecting floor of the oral cavity and ventral surface of the tongue

Lips

structures bounding oral fissure

possess long, tactile hair and regular hair

Cheek

Caudolateral wall of the oral cavity

Gums

also known as gingivae

oral mucosa over the jaws

encloses the neck of the teeth

Palate

roof of the oral cavity

composed of the hard palate and soft palate

Hard palate

osseous plate and its vascular mucosal covering

separates oral and nasal cavities

Soft palate

caudal extension of hard palate

divides rostral region of pharynx into oral and nasal parts

Palatine ridges

6-10 paired elevations crossing the hard palate transversely

Do ruminants have upper incisors?

no, they have a dental pad

Dental pad

replaces upper incisors and canines in ruminants

provides heavily cornified epithelium for the lower incisors to grind food against

Functions of the tongue

1. taste buds
2. mechanical function - enable food / water to retrograde
3. young use for suckling
4. temperature control (dog) by panting
5. Grooming comb (cats are poster child for this)

Torus linguae

round swelling of caudodorsal surface of the ox's tongue

What does the torus linguae allow cattle to do?

enables them to chew cud and go to sleep with mouth full of roughage without chocking

Principle function of mastication

aids in prehension - food gathering

weapons in some species

Brachydont teeth

simple teeth of carnivores, pigs, ruminant's incisors, and horse's deciduous incisors

consists of crown, neck, and root

Crown

Part projecting above the gum line

covered with enamel

What separates the thoracic and abdominal cavities

diaphragm

Innervation of the tongue

taste - cranial nerves VII, IX, and X

Sensation - cranial nerve V

Motor - cranial nerve XII

Body Cavities

compartment of the body

Neck

constriction between crown and root at the gum line

Neck

constriction between crown and root at the gum line

Root

part below the gum line embedded in the alveoli

Hypsodont teeth

teeth having no distinct neck

horse's permanent teeth, ruminant cheek theeth, tusks of pigs

continue to erupt throughout life (except horse's canine teeth)

Body of the tooth

different from brachydont teeth due to absence of a neck

Root of the teeth

Part below the gum line; embedded in alveoli (bony sockets) of incisive, mandible, or maxillary bones

Enamel

hardest substance in the body

Brachyodont - covers only the crown

Hypsodont - covers body

Dentin

hard substance, similar to bone

forms bulk of tooth

surrounds pulp cavity

Cementum

thin, bone-like covering

Brachydont - covers root only

Hypsodont - covers entire tooth, superficial to enamal

Pulp cavity

central space of tooth that contains the pulp

Pulp

soft tissue filling the pulp cavity

What does the pulp include?

1. sensory nerves
2. arteries
3. veins
4. lymphatics
5. primitive connective tissue

Periodontal membrane

dense fibrous connective tissue connecting the wall of the alveoli and the cementum covering the teeth

Alveoli

bony sockets of the incisive, mandible, and maxillary bones

roots of teeth embedded here

Overshot Vs. undershot

elongated jaw vs. shortened jaw

Vestibular surface of the teeth

faces lips or cheeks

Lingual surface of the teeth

faces tongue

Contact surface of the teeth

side adjacent to next tooth

Mesial surface of the teeth

faces median plane on the incisors, rostral on canine and cheek teeth

Distal contact surface of the teeth

faces away from median plane on incisors, caudal on canine and cheek teeth

Incisors

rostral-most teeth

embedded in incisive bone (upper) and mandible's incisive part (lower)

Canine

large tooth between the incisors and cheek teeth (premolars and molars)

Premolars

rostral cheek teeth

Molars

caudal cheek teeth

Deciduous

baby teeth

functional set of teeth in young animals

smaller and fewer in number than permanent dentition

Permanent teeth

adult teeth

must last the life of the animal

Carnassial teeth

large, shearing teeth of dogs and cats

Upper P4 and lower M1

Tusks

canine teeth of the pig

lower tucks larger than the upper

boar's larger than sow's

Wolf teeth

horses rudimentary upper first premolars; often absent

Carnassial tooth abscess

Upper P4

results in swelling or draining (pus) below the carnivore's eye

should be split when extracted

Needle teeth

pig's deciduous third incisors and canines

"nipped" off newborns for sow's benefit while suckling

Floating teeth

filing off sharp edges/points of the horse's cheek teeth

Tooth roots

can have 1-3 roots

Dog's aging using teeth

deciduous erupt by 6 weeks; permanent by 6 months

Cat's aging using teeth

deciduous erupt by 6 weeks; permanent by 6 months

Salivary glands

extramural glands emptying into the digestive system via ducts

preparation of food for swallowing begins with lubrication and wetting by salivary secretions

Parotid salivary gland

below the ear

Mandibular

next to mandibular lymph node

Sublingual

under the tongue

Pharynx

acts as common passageway for digestive and respiratory system

connects nasal and oral cavities with trachea and esophagus

directs food intake and air into proper channels

Nasopharynx

part of respiratory channel

located dorsal to soft palate

extending from caudal nares to laryngopharynx

Oropharynx

part of digestive channel

ventral to soft palate

extending from oral cavity to base of epiglottis

Laryngopharynx

part of pharynx where air from nasopharynx crosses to reach the larynx and food and water from oropharynx crosses into esophagus

part of both respiratory and digestive channels

located between base of epiglottis and the esophageal entrance

Piriform recess

continuation of the floor of the oropharynx on either side of the larynx

Soft palate

caudal musculomucosal continuation of the hard palate

divides rostral part of pharynx into oropharynx and nasopharynx

Pharyngeal opening

opening from oral cavity to oropharynx

formed by soft palate, tongue, etc.

Caudal nares (choanae)

osseous opening between caudal nasal cavity and nasopharynx

Pharyngeal openings of auditory tubes

slits in lateral walls of nasopharynx

lead into auditory tubes

Layngeal opening

opening int larynx

surrounded by rostral laryngeal cartilages

Esophageal opening

opening at caudal end of laryngopharynx into esophagus

Tonsil

aggregation of lymphatic tissue in pharyngeal mucosa

named according to locations

helps protect openings of pharynx against microorganisms and toxic substances

Palatine tonsil

lymphoid aggregation in oropharynx

Esophagus

first part of alimentary canal

muscular tube

transports food from oral cavity and pharynx down the neck and through the thorax to the stomach

has cervical, thoracic, and abdominal parts

What does the esophagus pass down?

the neck dorsal to trachea and then shifts to the left of the trachea
(inside thorax, returns dorsal to trachea)

What does the esophagus pierce?

Pierces esophageal hiatus of diaphragm
(terminates in short abdominal portion at cardia for the stomach)

Stomach linings

Nongladular - continuation from esophagus

glandular - continuous into duodenum

Stomach linings in both carnivores and composite stomachs

carnivores have glandular stomach lining

composite stomach has both linings (ruminants, horse, pigs)

Simple stomach

single compartment stomach

carnivores, horse, and pig

greater curvature

long, convex surface of stomach

extends from cardia to pylorus