Secretions of the digestive tract Flashcards
Name the 4 secretions of the digestive tract.
Bile, pancreatic juice, gastric juice, saliva
Why must the animal constantly reabsorb the secretions it produces?
The secretions include large volumes of electrolytes/ fluids, therefore need to reabsorb these
What 2 substances in saliva have antibacterial properties?
Lysozyme, antibodies
Name the enzyme used in the saliva in omnivores and neonates.
Salivary amylase (omnivores), lingual lipase (neonates)
Do the enzymes continue to work in the stomach, or do they become inactive? why?
The enzymes become inactive due to the low pH of the stomach
Once electrolytes are resabsorbed within the salivary ducts, what type of solution is produced?
hypotonic
What neurotransmitter is utilised for the facial, glossopharyngeal and cranial nerves?
acetylcholine (ACh)
Are the salivary glands under sympathetic or parasympathetic control?
Parasympathetic
What afferent (sensory) stimuli result in increased salivation?
Chewing, stimulation of taste buds, anticipation (like pavlovs experiments)
When is a time that sympathetic stimulation causing release of B-adrenergic receptors will cause salivation?
In dogs about to attack
What is different about the regulatory component for saliva, compared to other digestive secretions?
There is no endocrine regulatory component (not directly controlled by hormones, instead is stimuli)
What ions are found in higher concentrations in ruminant saliva, what type of solution does that make the saliva?
Bicarb and phosphate ions which make the solution isotonic
Why are there higher amount of species-specific ions in ruminant saliva than other animals.
The ions (bicarb and phosphate) make the saliva more basic (higher pH) buffering the very acidic VFA produced in the rumen
If a ruminant does not produce 100-200L/ day of saliva, what can occur?
Acidic bloat, dehydration
Aside from the non-glandular stomach being a site of gastric ulcers in the rat/ horse, what can occur here?
Fermentation
