Alimentary Canal Flashcards
Explain the part of the alimentary canal, “Stomach” and what it does.
Stomach:
Protease enzymes break down proteins in chemical digestion. The food is also churned to break it up even more by mechanical digestion. Hydrochloric acid is also present in the stomach to kill off bacteria by creating extremely acidic conditions.
What process allows the oesphagus to move food down from the mouth to the stomach?
Peristalsis.
What does the salivary glands do in the mouth?
The salivary glands release saliva which contains carbohydrase enzymes which begins the chemical digestion of strach.
How is food mechanically digested in the mouth?
Food is mechanically digested in the mouth by the teeth.
What are the 2 parts of the small intestine and what role do they play?
The small intestine contains the duodenum and ileum. In the duodenum, the acidity from the stomach is neutralized and protease, lipase and amylase enzymes are secreted to break down molecules. The ileum is the final part of the small intestine and this is where the products of digestion are absorbed in the blood.
What substance does the pancreas secrete, where is it secreted and what enzymes does it contain?
The pancreas secrets pancreatic juices into the small intestine. this contains, lipase, protease, and amalyse enzymes to break down food so that it can be absorbed.
What alkaline substance does bile make, where is it secreted and what are the functions of this substance?
The liver makes bile. Bile is secreted in the small intestine and has 2 functions: Firstly, it neutralizes the acidic conditions from the stomach because it’s alkaline to provide a suitable ph for enzymes to work at. It also emulsifies fats, increasing their surface area so enzymes can digest them more quickly.
Where is the bile stored before it is secreted into the small intestine.
Bile made in the liver is stored in the gall bladder before being secreted into the small intestine.
What is the purpose of the large intestine
Indigestible food passes through the large intestine which consists of colon, retum and the anus. Remaining salts are absorbed here (most of it is absorbed in the small intestine) The anus then pushes food out of the body as feaces because the body can no longer make use of the indigestible foods.
Explain the whole process of the alimentary canal and how food is chemically and mechanically digested?
Once food is ingested, it goes under both chemical and mechanical digestion as it is broken down. Mechanical digestion breaks down the food into smaller molecules without chemical change. This occurs in the mouth due to chewing and in the stomach, the food is churned. Chemical digestion is the breaking down of larger, insoluble molecules into smaller soluble molecules with the use of enzymes, so that the product can be absorbed. Absorption occurs as the smaller molecules and the ions pass through the walls of the small intestine into the blood. These molecules then travel around the body, where they are assimilated into cells and used in metabolic reactions. Food that is not digested and absorbed is egested as faeces.
