6.1 Digestion and absorption Flashcards
What is the alimentary canal?
The alimentary canal consists of organs through which food actually passes. This includes the stomach, oesophagus, large intestine and the small intestine.
What are the accessory organs?
The accessory organs consist of organs that aid with digestion but food is not transferred.
What is the role of the oesophagus?
To connect the oral cavity to the stomach. Food is mixed with saliva and moved in a bolus via the action of peristalsis.
Where does protein digestion begin?
The stomach
What is the role of the stomach?
The role of the stomach is to act as a temporary storage tank where food is mixed by churning. Protein digestion begins in the stomach.
The stomach is lined with gastric pits that secrete digestive juices that lower the pH of the stomach and create an acidic environment.
What is the role of the small intestine?
The small intestine is where usable food substances are absorbed.
What does the small intestine consist of?
It consists of the duodenum, the jejunum and the ileum.
What is the role of the large intestine?
Where water and mineral ions are absorbed. Consists of the sigmoidal colon as well as the rectum.
What is the role of the salivary glands?
The role of the salivary glands is to moisten food and to release enzymes to help with the breakdown of starch. Eg amylase. Salivary glands include the parotid gland, submandibular gland and sublingual gland
What is the function of the pancreas?
The pancreas secretes a broad range of enzymes such as protease, amylase and lipase. Through the use of the duodenum connects to the stomach where these enzymes are used. Secretes hormones such as insulin and glucagon which control blood-glucose concentrations.
What is the function of the liver?
The liver produces bile, storage, metabolism. The liver takes the raw materials absorbed by the small intestine and uses them to make key chemicals.
What is the function of the gall bladder?
Gall bladder stores the bile produced by the liver. The gall bladder uses the bile duct to transfer the bile to the small intestine.
What are the two ways by which digestion takes place?
Digestion takes place through chemical and mechanical digestion.
What takes place in the mouth (digestion)
Food is initially broken down in the mouth through chewing by the grinding action of teeth. Tongue pushes food to the back of the mouth where it travels down the oesophagus as a bolus.
Examples of mechanical digestion
Mastication, also known as chewing is how food is broken down in the mouth. The food is pushed to the back of the mouth where it travels down the mouth as a bolus. The epiglottis prevents the bolus from entering the trachea, while the uvula prevents the bolus from entering the nasal cavity.
What is a caudal direction?
From the mouth to the anus
What is peristalsis
SLOPG - LSM
Occurs in the stomach, gut and the oesophagus. It the movement. Continuous segments of longitudinal smooth muscle contract and relax.
What is segmentation?
Segmentation contains circular smooth muscle and is multidirectional for the chyme (the chyme is a product of churning in the stomach), this allows for a greater mixing of foods with digestive tissue. Takes place in the intestine. Non-adjacent segments of circular tissue that are contracted and relaxed. Though segmentation allows for better physical digestion of food particles, it is very slow.
What do stomach acids allow?
Stomach acids allow gastric glands to release digestive acids which will lower the pH of the stomach. this low pH will denature proteins and other macromolecules that will aid in their digestion. contains a mucous membrane that will
What do bicarbonate ions do?
neutralise stomach acid
