prehension, mastication and ensalivation Flashcards
prehension
moving food into mouth for mastication; use hands/paws, lips, teeth, or tongue
how do dogs and cats hold prey
hold with paws/ claws, use canines to grip with wide opening mouth, chop prey using carnassial teeth
wolves tend to hunt:
feral cats tend to hunt:
- easiest option available; require stimulus of running animal to proceed w attack, an prey that holds its ground has greater likelihood of survival
- live prey
how do predators kill medium-sized prey
- bite throat
- sever nerve tracks and carotid artery thus causing animal to die quickly
how do predators kill small prey
leap in high arc and immobilize with their forepaws
mastication
to chew; cutting or grinding food into smaller pieces for swallowing
saliva
complex secretion resulting from several glands; many are small in mucosa or submucosa or lips, tongue and palate whereas salivary glands proper are large with well-defined ducts
mastication in carnivores
- minimal
- meat or bone cut into smaller bits by carnassial teeth
- temporal muscle creates strong vertical force
name the salivary glands
parotid, mandibular, sublingual and zygomatic which is only in carnivores
function of saliva
- moisten and lubricate mouth and pharynx
- maintain health w antimicrobial properties and buffering agents
- dissolving substances to be tasted
- help suspend, bind together and lubricate food
- thermoregulation
- amylase in some species; initial breakdown of carbs
serous glands
produce watery secretion which may contain enzymes, stain basophilic (purple)
mucous glands
produce mucin, columnar, pale staining with basal nuclei
mixed glands
serous and mucous secreting cells
may form demilunes; cap of serous secreting cells sits around an acini (alveoli) containing mucous secreting cells
proper salivary glands have some combo of ______ patterns and known as ________ with a complex system of ducts
tubular and alveolar patterns
tubulo-alveolar glands
the acini or alveolus portions of salivary glands are made up of
pyramid-shaped cells around a central lumen, surrounded by contractile myoepithelial cells
the glandular portions of salivary glands and their associated ducts are separated
by connective tissues into lobules; multiple lobules form a lobe
ducts that lie within the lobes of salivary glands are known as
intralobular
ducts that lie between the lobes of salivary glands are known as
interlobular ducts
bigger ducts
intercalated ducts
first part of the intralobular duct, short duct which have cuboidal cell type, very small lumen
they empty into larger striated ducts with taller cells
striated ducts
intercalated ducts empty into striated ducts with taller cells
here the basal membrane appears striated due to numerous infoldings of the basal membrane which increase the SA for the modification of saliva
after striated ducts, the ducts get larger and the epithelium changes from
columnar to cuboidal as cells become less active and require less cytoplasm
sometime stratified cuboidal ducts seen (2 layers)
parotid gland
- lies in retromandibular fossa (space between ramus of mandible and wing of atlas) and dorsally comes up to base of external ear
- triangular or club like shape over horizontal ear canal
- lighter colour
- serous
- partly covered by parotidoauricular msucle
parotid ducts
crosses lateral masseter muscle between dorsal and central buccal nerves and opens at parotid papilla
mandibular gland
- caudal and medial to angle of jaw
- partly covered by parotid
- well encapsulated in dog and cat
- mixed gland (mainly mucous in cat and dog)
- opens near frenulum at rostral most opening of sublingual caruncles
sublingual gland
- floor of mouth
- mixed, mainly mucous
- the monostomatic sublingual gland; single duct opens close to or with mandibular duct
- the polystomatic sublingual gland consists of chain of lobules, each discharging through own duct into lateral sublingual recess
zygomatic gland
- dorsal buccal
- carnivores only
- rostral orbit
- between zygomatic arch and eyeball
- drains to papillae near parotid papillae, lateral to upper M1
von ebner glands
- minor glands
- serous
- sit under foliate and circumvallate papillae
molar glands in cats
- minor glands
- large labial glands
- caudomedial to lower M1
salivary gland receive both sympathetic fibres through ______
and parasympathetic fibers from _____
- nerve plexuses around blood vessels
-parasympathetic components of facial and glossopharyngeal nerves
typically sympathetic stimulation increases or decreases salivation
vasoconstriction (decreases salivation)
however direct effect of increased secretion occurs w increased stimulation ie hypersalivating aggressive dogs
typically parasympathetic stimulation increases or decreases salivation
- increases; vasodilation
- contraction of myoepithelial cells
Which of the following is the MAIN structure used by rodents to stabilise food and move it to the mouth for mastication?
forelimbs
Which of the following muscles contributes the MOST to the large crushing force of the jaws in carnivores?
Temporalis muscle
Which of the following is NOT one of the large, major salivary glands?
Parotid gland
Mandibular gland
Lingual gland
Zygomatic gland
Lingual gland
Which type of salivary glands produce a watery secretion which may contain enzymes, and tend to stain basophilic (purple) in a H&E stain?
serous
Which major salivary gland lies in the retromandibular fossa, and comes up to the base of the external ear dorsally?
parotid gland
Swelling of which of the following glands can cause proptosis of the eyeball?
zygomatic gland
An increase in parasympathetic stimulation causes what effect on salivation?
increases salivation
There are 4 large, “proper” salivary glands, which are generally a combination of tubular and alveolar patterns and have a complex system of ducts. Which of the following is one of the 4 large, major salivary glands?
Palatine gland
Sublingual gland
Lingual gland
Labial gland
sublingual gland
