Gastrointestinal Flashcards
(19 cards)
Role of mastication
To mix food with saliva
Where does mechanical digestion start
What is food converted to
What is chyme
Mouth
Starts in mouth
When bolus mixes with gastric juice
Why doesn’t lipase digest fats in mouth
Because we need emulsification
Main function of digestive system
Prepares for for use by cells through
Ingestion taking in food
Mixing and movement of food : muscular contractions that mix food with secretions
Digestion: breakdown of food by chemical and mechanical processes.
Absorption : movement of digested food from GI tract into the cardiovascular and lymphatic system for use by cells
Defecation: removal elimination of indigestible substances
List 3 accessor y organs it GI tract
Mouth, tongue, pancreas
What is the role of saliva
Moisturizing
Protects against pathological bacteria due to lysosymes and IgG
All tubular organs have smooth muscle except
Mouth esophagus
What part of the esophagus is not a smooth muscle
Upper 1/3 is striated muscle
Middle 1/3 is mixed
Anal sphincter is striated
Advantage of striated muscle
it is under control
What is the function of lips and cheeks
To keep the food between the upper and lower teeth
What is the role of the tongue
aids in swallowing by increasing the pressure between bubbles
Forces food to move to the back of the mouth
Also participates in speech
Functions of salivary glands
To moisturize the food and form bolus
Role of saliva
Contains IgA and lysosomes which destroys bacteria thereby preventing infections
Mucus in saliva lubricates food for easy swallowing
Salivary lipase begins the digestion of carbohydrates
What is salivation and what system controls it
It is under the control of the sympathetic and parasympathetic system 
Salivation is the secretion and formation of saliva
What is the role of the parasympathetic system in salivation?
It ensures continuous production of saliva, making the mouth always moist
What is the role of the sympathetic nervous system?
Less saliva is produced during stress, accounting for dryness of the mouth
What happens in the mouth during dehydration?
less saliva is produced which leads to dryness and thirst sensation 
Explain mastification
This is the mechanical breakdown of food where food is mixed with saliva and reduced to a soft flexible mass known as bolus and can easily be swallowed
What is the role of the isthmus faucium
It is the border between the oral cavity and the pharynx whereby when bolus crosses this part, it is impossible to be controlled
