1. Salivary glands: These glands are located in the mouth and secrete saliva, which helps in moistening food and initiating the process of digestion.
2. Gastric glands: These glands are located in the stomach and secrete gastric juice, which contains hydrochloric acid, pepsin, and mucus. Hydrochloric acid kills bacteria and creates an acidic environment necessary for the activation of pepsin, which breaks down proteins. Mucus protects the stomach lining from the acidic environment.
3. Intestinal glands: These glands are located in the small intestine and secrete intestinal juice, which contains enzymes such as amylase, lipase, and protease. Amylase breaks down carbohydrates, lipase breaks down fats, and protease breaks down proteins.
4. Goblet cells: These cells are located throughout the alimentary canal and secrete mucus, which helps in lubricating food and protecting the lining of the digestive tract.
5. Brunner's glands: These glands are located in the duodenum, the first part of the small intestine, and secrete alkaline mucus, which helps in neutralizing the acidic chyme coming from the stomach and creating a more suitable environment for the enzymes in the small intestine to work.
6. Crypts of Lieberkühn: These are small tubular glands located in the lining of the small intestine and colon. They secrete mucus, enzymes, and water, which help in the digestion and absorption of nutrients.
7. Paneth cells: These cells are located at the base of the crypts of Lieberkühn and secrete antimicrobial substances called defensins, which help in protecting the intestine from harmful microorganisms.
8. Liver: The liver is not directly part of the alimentary canal but plays a crucial role in digestion. It produces bile, which is stored in the gallbladder and released into the small intestine when needed. Bile helps in the emulsification and digestion of fats.
9. Pancreas: The pancreas is also not directly part of the alimentary canal but secretes pancreatic juice, which contains enzymes such as amylase, lipase, and protease, as well as bicarbonate ions, which help in neutralizing the acidic chyme coming from the stomach.