Lesson 2.4.2 The Mouth, Pharynx, and Esophagus Flashcards
Where is ptyalin produced?
Ptyalin is an amylase enzyme in saliva.
What does ptyalin do?
It begins the breakdown of carbohydrates into glucose.
What type of digestion occurs in the stomach?
The stomach is where the greatest active chemical digestion begins.
What action assists the digestion of food in the stomach?
Stomach-muscle contractions assist the digestive process by kneading the partially digested food.
What are the gastric juices composed of?
Gastric juices contain hydrochloric acid (HCl), enzymes, and water.
What protects the stomach from the gastric juices?
This potent mix of chemicals is so strong that the stomach’s membrane lining secretes a protective mucus barrier to prevent these corrosive gastric juices from damaging the walls of the stomach. Without adequate mucosal protection, the stomach lining would be burned by the stomach’s own acids, creating painful stomach ulcers.
How long does digestive action in the stomach take?
Digestive activity in the stomach lasts anywhere from one to four hours per meal depending on the combination and amounts of food ingested
In what order do the nutrients pass through the stomach?
Liquids pass through the stomach most quickly, next comes carbohydrates, then proteins, and finally, fats.
What is the semi digested food called?
Chyme.
What releases chyme from the stomach?
The pyloric sphincter.
