GI Physiology Exam 2 (IP3): Oral Digestion Lecture

________________: seizing and conveying food into the mouth

prehension

prehensile organs in cattle

tongue

(grasping, scooping)

prehensile organs in sheep

tongue, cleft upper lip

(grazes close to ground)

prehensile organs in horse

mobile upper lip

(capable of fine motor movement)

prehensile organs in pig

pointed lower jaw

(shoveling action)

herbivores/omnivores intake fluid via what action

suction

which herbivore's prehensile organ is its mobile upper lip which is capable of fine motor movement

horse

which herbivore's prehensile organ is its tongue which it uses for grasping and scooping

cow

which omnivore's prehensile organ is its pointed lower jaw capable of a shoveling action

pig

which herbivore's prehensile organ is its tongue/cleft upper lip which allows it to graze closer to the ground

sheep

carnivores intake fluid via what action

lapping

(herbivores/omnivores/carnivores) intake fluid via suction

herbivores, omnivores

(herbivores/omnivores/carnivores) intake fluid via lapping

carnivores

prehensile organs for carnivores involve ________, ________, and ________ which all aid in tearing movements

teeth, jaw, head

where does digestion start

mouth

oral digestion involves (mechanically/chemically) break down food and (mechanically/chemically) digests carbohydrates and fats

mechanically, chemically

oral digestion prepares the food for further processing in the ________ and _________

stomach, intestines

mastication (increases/decreases) the size of foodstuffs

decreases

mastication (increases/decreases) the surface area

increases

mastication breaks off _________ outer covering

hint: organic polymer

cellulose

mastication mixes food with ________-

saliva

the mastication of (omnivores/herbivores) involves thorough grinding of plant matter

both

omnivores do thorough mastication on plant diet and ________ on carnivorous diet

gulping

carnivores masticate only to reduce food to ______________ size

swallowing

tooth decay involves the formation of _________ (precipitate of food and saliva)

plaque

oral __________ colonize plaque

bacteria

more sugar in diet = (more/less) bacteria growth

more

in terms of tooth decay, bacteria produce ________ and __________

lactate, protease

_________ __________ dissolves CaPO4

lactic acid

____________: demineralization of enamel and destruction of protein matrix

caries (cavities)

cavity formation involves the demineralization of _________ and destruction of _________ matrix

enamel, protein

dental cavities (are/are not) common in dogs and cats

are not

what is more likely in cats and dogs, cavities or gingivitis

gingivitis

what mineral replaces the -OH groups on hydroxyapatite and is bactericidal

fluoride

fluoride becomes ______________ when it replaces the -OH groups on hydroxyapatite

fluorapatite

fluoride becomes fluorapatite when it replaces the ______ groups on ______________

-OH, hydroxyapatite

fluorapatite, (increases/decreases) susceptibility to acid

decreases

mastication is mainly (involuntary/voluntary), but has a (involuntary/voluntary) component

voluntary, involuntary

what is the stimulus for the chew reflex

presence of food in the mouth

(activation/inhibition) of motor neurons to jaw musculature causes the jaw to drop, which ____________ jaw musculature causing a reflex contraction

inhibition, stretches

reflex chewing can be activated by doing what to the jaw to intubate, even in an anesthetized animal

pulling the jaw down

saliva is combined secretions of what 3 paired salivary glands

parotid, sublingual, submandibular

parotid gland secretions are primarily (mucous/serous)

serous

sublingual and submandibular gland secretions are primarily (mucous/serous)

both

secretory cell types of (parotid/sublingual/submandibular) glands are watery

parotid

secretory cell types of (parotid/sublingual/submandibular) glands are thicker

sublingual, submandibular

Salivary Flow rate:

_______________ periods (between meals): small tonic activity in most species

interdigestive

Salivary Flow rate:

interdigestive periods (between meals): are (small/large) (phasic/tonic) activity in most species

small, tonic

Salivary Flow rate:

ruminants have a (small/high) output in order to buffer rumen VFAs (acidic)

high

Salivary Flow rate:

ruminants have a high output in order to buffer rumen _____s which are acidic

VFAs

there is (decreased/increased) salivation with feeding and/or rumination

increased

salivary secretion volume varies according to the animal's what?

dietary specialization

the (horse/dog/cattle) produces 40 gallons of saliva a day

cattle

the (horse/dog/cattle) produces 0.5 quarts of saliva a day

dog

the (horse/dog/cattle) produces 10 gallons of saliva a day

horse

in non-ruminants, saliva is (hypertonic/isotonic/hypotonic) relative to plasma when flow rates are low

hypotonic

in non-ruminants, what are the 4 primary ions present in the saliva

sodium, chloride, bicarbonate, potassium

in non-ruminants, at (low/high) flow rates, saliva tends to be slightly acidic

low

in non-ruminants, at low flow rates, saliva tends to be slightly (basic/acidic)

acidic

T/F: in non-ruminants, various blood components can diffuse into saliva

true

in non-ruminants, primary secretion occurs at the ______ cells of the ____ gland

acinar, salivary

in non-ruminants, the composition of the fluid secreted by the acinar cells of the salivary glands resembles _______________ but lacks proteins

extracellular fluid

in non-ruminants, the composition of the fluid secreted by the acinar cells of the salivary glands resembles extracellular fluid but lacks ________

proteins

in non-ruminants, the composition of the fluid secreted by the acinar cells of the salivary glands contains what 5 ions

sodium, chloride, bicarbonate, potassium, and water

in non-ruminants, ductal modifications varies with ______ rate

flow

in non-ruminants, at (low/high) fluid rates saliva is modified as it travels through the ducts

low

in non-ruminants, at (low/high) fluid rates there is less time for ductal modifications

high

in non-ruminants, at (low/high) fluid rates saliva composition closely resembles the primary acinar secretion

high

in non-ruminants, at (low/high) fluid rates NaCl is absorbed via coupled exchangers: Na+/H+ and Cl-/HCO3-

low

in non-ruminants, at (low/high) fluid rates protons (H+) are excreted via uncoupled Na+/H+ exchange

low

in non-ruminants, at (low/high) fluid rates potassium is secreted into the saliva

low

in non ruminants, duct epithelium is (leaky/tight)

tight

in non ruminants, duct epithelium is tight which prevents (ion/water) reabsorption and only (ions/water) is/are absorbed

water, ions

in non-ruminants, at high flow rates there is (more/less) time for ductal modifications

less

in ruminants, saliva is (hypotonic/isotonic/hypertonic) at all flow rates

isotonic

in ruminants, saliva is isotonic as (low/high/all) flow rates

all

in ruminants, (HCO3-/PO4-) is an important buffer as low flow rates and switches to (HCO3-/PO4-) at higher flow rates

PO4-, HCO3-

ruminants have (acidic/alkaline) saliva

alkaline

what is the pH level of ruminant saliva

8

the alkaline properties of ruminant saliva serves to buffer the pH of which stomach

rumen

(mucin/salivary amylase/urea/lysozymes/secretory antibodies): passively diffuses from blood into salivary ducts

urea

(mucin/salivary amylase/urea/lysozymes/secretory antibodies): found in species like pigs and humans. begins starch digestion by hydrolyzing starch into maltose

salivary amylase

(mucin/salivary amylase/urea/lysozymes/secretory antibodies): enzymes that break down bacterial cell walls

lysozymes

(mucin/salivary amylase/urea/lysozymes/secretory antibodies): provide immune protection in the oral cavity

secretory antibodies

(mucin/salivary amylase/urea/lysozymes/secretory antibodies): a glycoprotein that lubricates food and protects oral tissues

mucin

(mucin/salivary amylase/urea/lysozymes/secretory antibodies): are considered bactericidal compounds that help maintain oral hygiene and prevent infection

lysozymes and secretory antibodies

salivary amylase begins _______ digestion by hydrolyzing it into maltose

starch

salivary amylase begins starch digestion by hydrolyzing it into __________

maltose

what is the optimal pH level for salivary amylase

7

urea (actively/passively) diffuses fro, the blood into the salivary ducts

passively

urea is important for urea recycling in ruminants. it helps to aid in microbial _______ synthesis in what stomach?

protein, rumen

mucin is a (polypeptide/glycoprotein/lipid)

glycoprotein

Afferent input to the salivary nuclei of the CNS:

(conditioned/unconditioned) reflexes are associated with the anticipation of eating

conditioned

Afferent input to the salivary nuclei of the CNS:

the stimuli for (unconditioned/conditioned) reflexes involves chemical and mechanical signals, tactile receptors, and taste receptors

unconditioned

Afferent input to the salivary nuclei of the CNS:

the stimuli for (unconditioned/conditioned) reflexes involves visual, auditory, and olfactory

conditioned

Afferent input to the salivary nuclei of the CNS:

(unconditioned/conditioned) reflexes are triggered by the presence of food in the mouth

unconditioned

Afferent input to the salivary nuclei of the CNS:

unconditioned (oral/abdominal) reflexes are triggered by the presence of food in the mouth

oral

Afferent input to the salivary nuclei of the CNS:

unconditioned (oral/abdominal) reflexes receive stimuli from deeper into the digestive tract and is usually pathological

abdominal

unconditioned abdominal reflexes involve receptors and afferents from what three regions

esophageal, gastric, intestinal

what 3 kind of receptors involved with unconditioned abdominal reflexes can be found in the esophageal, gastric, and intestinal regions

chemical, mechanical, nociceptive (pain)