DIGESTIVE SYSTEM

• Digestive system is anatomically diverse for some species but the function is similar to all which is extract and absorb
• Main organs of digestive system: mouth, esophagus, stomach, small intestine, large intestine, salivary glands, liver, gallbladder, and pancreas, anus
• Two types of anatomy of digestive system: monogastric and polygastric
• Organs of prehension: tongue, lips, teeth, beak 
• Ruminant's doesn't have incisor teeth but has a functional dental pad for severing grass
• 3 major salivary glands: parotid glands, submaxillary glands, and sublingual glands
• Muscle of mastication: masseter, pterygoid, and temporalis muscle
• Poygastric animals has four stomach compartments: rumen, reticulum, omasum, abomasum
• Functions of saliva: moistens, lubricate, provide digestive action, maintain water balance, buffer, source of recycled nutrients
• Classification of mono-gastric: monogastric carnivores, monogastric omnivores, monogastric herbivores
• Four regions of gastric stomach of monogastric: cardia, fundus, body, pylorus
• Digestive action - saliva has enzymes that breaks down starch or complex carbohydrates called amylase or alpha amylase
• Saliva buffer - saliva has ions that maintain the pH level of stomach's acidity
• Saliva water balance - if water is lacking, salivary glands will be dehydrated that will cause a sensation of thirst and stimulates to makes them drink water
• VFA or volatile fatty acids are also one of the source of energy for animals
• Salivary glands of cats: parotid, maxillary, sublingual, molar, zygomatic glands
• Salivary glands of dogs: parotid, maxillary, sublingual, zygomatic glands
• Cats are obligate or also called as strict carnivores
• monogastric carnivores like cats required preformed vit A, amino acid taurine, and fatty acid arachidonic acid
• what cells comprised the largest endocrine organ in the body?

  entero-endocrine cells
• layers of gut wall: external serosa, muscularis externa, mucosa (muscularis mucosa, lamina propria, mucous membrane)
• polygastric animals are all herbivores and pre-gastric fermenters
• the temporalis muscle of monogastric carnivores is greatly enlarge to have a strong bite force for capture and holding prey
• there is no ____ in cats

  alpha amylase
• what kind of digestive tract does monogastric carnivores havsmall and simple
• the stomach of large cats can expand to hold large meals while domestic cats can only suit to smaller meals
• this is an essential dietary amino acids for cats?

  taurine
• bears doesn't have a caecum and cannot digest low quality plants
• bears is an example of?

  monogastric omnivores
• monogastric herbivores are all ____?

  post gastric fermenters
• post gastric fermenters are further divided into: caecal fermenters and colonic fermenters
• caecal fermenters include rabbits, rodents, horses, ruminants (cattle, sheep)
• these are _____ fermenters if the animals are <5kg

  caecal fermenters
• these are _____ fermenters if the animals are >50kg

  colonic fermenters
• monogastric herbivores' saliva contains alpha amylase?

  yes
• where does the most absorption happen in small intestine?

  jejunum
• what is the major disadvantage of being monogastric herbivores?

  late absorption of vitamin B and K
• caecotrophy is when an animal is eating their feces to absorb the nutrients again
• what animals do caecotrophy that are advantage to them?

  rabbits
• monogastric herbivores have a well developed mastication muscle