Overview Of GI Tract Flashcards
What are the digestive organs?
Oesophagus
Stomach
SI
LI
What are the accessory organs?
Pancreas
Liver
What processes take place in the stomach?
Motility
Secretion
What processes take place in the SI?
Motility
Digestion
Absorption
What processes take place in the large intestine?
Motility
Fermentation
Absorption
Egestion
What is prehension?
Movement of food into the oral cavity
What is mastication?
Chew
What is the function of salivary mucous?
To lubricate food
What type of gland is a parotid gland?
Serous
What type of glands are mandibular, buccal, sublingual?
Mixed serous and mucous
In simple stomach animals,what is the pH of saliva? Why?
Neutral
To allow amylase function
In complex stomached animals, what is the pH of saliva?
Alkaline to buffer forestomach for fermentation
What is saliva composed of?
Mucin & water = mucous Amylase (not carnivores or ruminants) Bicarbonate Phosphate (ruminants) Lysozymes/antibodies Protein binding tannins (leaf eaters) Urea (ruminants)
In non-ruminants, describe the tonicity of saliva at normal, low and high saliva flow rate.
Normal: isotonic
Low: hypotonic
High: remains isotonic
In ruminants, describe the tonicity and which compounds predominate at normal, slow and fast salivary flow rate.
Always isotonic
Low- PO4 predominates
High- HCO3 predominates
Salivary secretion is under what type of control?
Neural
What are the two types of reflex that cause saliva secretion, and what stimulates them?
Congenital: smell, taste, feel of food in mouth
Conditioned: learned and associated with noise/sight
Swallowing,chewing and defaecating are under voluntary control. What type of muscle controls this?
Skeletal muscle
Digestive contractions are under involuntary control. What type of muscle controls this?
Smooth muscle
Where are enzymes that breakdown carbohydrates released from?
Saliva
Pancreas
Intestinal mucosal surface
Where are enzymes that breakdown protein released from?
Stomach glands
Pancreas
Intestinal mucosal surface
Where are enzymes that breakdown fat released from?
Pancreas
Intestinal mucosal surface